The July full "Buck Moon" rises tonight to lead Saturn, Mars and Mercury in a spectacular mini planetary parade through the summer sky. Here's what you need to know.

July's full moon phase occurs at 10:36 a.m. EDT on July 29 (1436 GMT), when the lunar disk will appear fully illuminated. It's often called the Buck Moon, to reflect the time when young male deer grow out their antlers. It has also been named the Berry Moon by the indigenous Anishinaabe people and as the Thunder Moon by the Western Abenaki people, according to the Old Farmer's Almanac.

Look to the southwestern horizon at sunset to catch the full Buck Moon as it creeps slowly into the summer sky. The moon may appear particularly large at moonrise thanks to a phenomenon known as the "Moon Illusion", where our brains trick us into perceiving it as larger than it actually is while close to the horizon. You might also see it adopt a yellow-orange hue as Earth's atmosphere scatters the bluer wavelengths of its light as it travels low in the sky.

Sunlight strikes the moon head on during July's full moon phase, leaving no shadows to emphasize the presence of the countless craters that litter the lunar surface. It's a perfect time to explore the dark lunar seas that scar the moon's surface, where ancient lava flows once flooded networks of impact basins, then hardened billions of years ago, repaving vast swathes of Earth's natural satellite.

Grab a pair of binoculars or a telescope and look a little closer. You'll find a network of bright streaks intersecting as they travel outward from youthful impact craters. These features are known as ejecta rays, and were created when material cast out in violent impacts fell back onto the lunar surface. Every crater on the moon once had its own set of ejecta rays. However, all but the most recent have since faded into obscurity due to space weathering.

Venus will appear as a bright evening star to the west after sunset, serving as the opening act for a magnificent planetary procession in the hours that follow. Saturn, Mars and Mercury will rise in the east to trail the moon in a majestic arc as it treads a ponderous path from east to west through the summer sky.

Want to capture the incredible predawn lineup for yourself? Then be sure to check out our guide to photographing the planets, along with our expert tips on photographing the moon. You can also read our roundup of the best cameras and lenses for astrophotography to ensure that you're ready for the next big skywatching event.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Look west sky after sunset on June 17 to witness a slender crescent moon gleaming alongside the stars of the Beehive Cluster at the head of a dazzling planetary parade.

Mercury's steady light will shine low on the western horizon in the glow of the setting sun, as while Jupiter glistens close to its upper left, with Venus and the moon lining up beyond to create a spectacular planetary display.

You may notice the soft glow of earthshine infusing the night side of the moon on June 17, as light bounces off our planet to illuminate the lunar crescent while it glides silently through the 1,000-strong stellar population of the Beehive cluster.

A pair of 10x50 binoculars will reveal dozens of the brilliant, young stars surrounding the three-day-old moon, while a 4-inch telescope will provide the magnification needed to highlight the cloud bands of Jupiter and its four large Galilean moons.

Mercury will be the first of the parade members to slip from view, less than two hours after sunset, while the moon will remain visible for another hour after that for stargazers in the U.S., before it dips below the western horizon.

The following night sees the waxing moon leave Venus and the Beehive Cluster behind, as it sweeps towards the blue-white light of Regulus — a multi-star system that glistens at the heart of the constellation Leo.

Mercury, meanwhile, will sink closer to the horizon with each passing night in the weeks that follow, as Venus rises away from Jupiter to chart a course through the constellation Cancer, before passing just 1 degree from Regulus on July 9.

Interested in snapping your own photos of the night sky? Then be sure to read our roundups of the best cameras and lenses for astrophotography, along with our beginner's guide to imaging the post sunset realm.

Editor's Note: Want to share your planetary photos with Space.com's readers? Then please send your image(s) and comments, along with your name and location to spacephotos@space.com.

Mercury reaches greatest elongation on June 15, placing the elusive planet at its farthest apparent distance from the sun in the evening sky. That makes this one of the best opportunities of the year to spot Mercury after sunset, shining below Venus and Jupiter in the western sky.

As an "inner" planet, Mercury never strays particularly far from the horizon compared to the outer planets like Mars and Jupiter, which shine brightly overhead from dusk to dawn at opposition, when they sit opposite the sun in Earth's sky.

Mercury's tight orbit around the sun sees it yo-yo back and forth between the evening and morning sky throughout the year. As such is it often lost from view in the glare of our parent star. The rocky world will reach its point of greatest elongation on June 15, when it will appear about 17 degrees away from our parent star — marking one of the best times to see it in its current evening apparition.

How to find Mercury on June 15

Look to the western sky at sunset to find Mercury shining less than 20 degrees above the horizon, with Jupiter and Venus forming a line to its upper left. The razor-thin crescent of the waxing moon will also be present to the lower right of Mercury, all but impossible to spot in the glow of the setting sun.

The weeks that follow will see Mercury's steady light move inexorably closer to the horizon with each passing night, leading up to its inferior solar conjunction on July 12, when it passes between the sun and Earth before transitioning to a morning object.

Want to catch striking images of the night sky? Then be sure to read our picks of the best cameras and lenses for astrophotography, along with our beginner's guide to imaging the night sky.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Mercury, Venus, and Jupiter align low over the western horizon after sunset tonight, creating a satisfying mini planetary parade and a perfect astrophoto opportunity using a wide-angle lens or even just a smartphone.

Even though Venus and Jupiter have drifted apart slightly since their tight embrace on June 9, Mercury has climbed up beautifully from the sun's glare to join the party. Together, they form a striking slanted line along the ecliptic in the west-northwestern sky right after sunset.

This is a high-speed game. The optimal viewing window starts exactly 30 minutes after your local sunset and lasts for only about 30 to 45 minutes before Jupiter and Mercury follow the sun below the horizon.

Look for blazing Venus first — it will pop out while the sky is still bright. Drop your eyes down and slightly to the right to easily spot Mercury and Jupiter.

For observers using telescopes or imaging equipment, June 12 also offers an interesting opportunity to compare the appearance of the three worlds. Venus will show a small, intensely bright, 80%-illuminated gibbous disk, while Mercury will present a stark contrast with its 50%-illuminated "half-moon" phase. Resolving a clean, tiny half-Mercury in twilight is an elite visual feather in any amateur's cap. Jupiter will appear as a much larger disk, although its low position above the horizon means atmospheric turbulence may blur some detail. Under steady conditions, advanced imagers may be able to capture hints of the planet's famous equatorial cloud belts alongside Mercury's sharply defined silhouette.

For photographers, however, June 12 is all about landscape composition. Put away the prime-focus telescope adaptors and grab a 50 mm to 85 mm prime lens on a DSLR/mirrorless camera. Expose for the deep twilight sky colors and frame the three planets as a slanted cosmic ladder ascending over a crisp local silhouette — like a mountain ridge, a distant city skyline, or a line of pine trees.

If you're looking for a telescope or binoculars to observe the night sky in more detail, our guides for the best binocular deals and the best telescope deals can help. Our best cameras for astrophotography and best lenses for astrophotography can help you get ready to capture the next stunning skywatching event.

Get ready for a spectacular sight tonight (June 9), as Jupiter and Venus make a close approach in the evening sky, while Mercury shines close to the western horizon in the glow of the setting sun.

Stargazers in the U.S. will see the bright light of Venus glowing less than 20 degrees above the horizon at sunset — roughly the width of two clenched fists held at arm's length — with Jupiter to its lower left. Mercury, meanwhile, is more challenging to spot, as it shines approximately 10 degrees below and to the lower right of the pair, requiring a clear view to the west.

Venus and Jupiter will be separated by less than 2 degrees in the night sky — close enough to share the field of view of a pair of 10x50 binoculars. You may also be able to spot Jupiter's four Galilean moons — Io, Europa, Callisto and Ganymede — appearing as tiny star-like points of light surrounding the gas giant.

The following nights will see Venus rise above Jupiter as it tracks a path toward the heart of the nearby constellation Cancer, where it will shine with the open star cluster Messier 44 — also known as Praesepe or the Beehive Cluster — on June 20.

Jupiter, meanwhile, will be progressively harder to spot following its rendezvous with Venus on June 9, appearing fractionally lower on the horizon with each passing night. By early July, the gas giant will be a challenge to spot in the glow of the setting sun, and won't be seen again until mid-August, when it reappears in the eastern morning sky.

Want to get a closer look at the planets? Then be sure to read our roundup of the best telescopes available in 2026. If you're a photographer, then you may also want to read our guide to the top smart telescopes for capturing the night sky, along with our picks of the most capable cameras and lenses for astrophotography.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

The June evening sky this year is exceptionally interesting.

A spectacular gathering of three planets, two bright stars, plus, later this month, a slender crescent moon, will be the chief celestial attraction in the evening sky during the next few weeks. It will, in fact, be possible for anyone with a clear and unobstructed view of the western sky to see all three planets at a single glance.

And two of these planets — Venus and Jupiter — are by far the brightest of those that are readily visible with the unaided eye. In fact, on one particular evening, Tuesday, June 9, these two worlds will seem to "call attention to themselves," even to those who normally do not look up into the night sky.

Jupiter and Venus draw together

No doubt during the past week or so, even casual sky watchers have already taken note of Venus and Jupiter in the guise of two very bright "stars" that have been evident in the west-northwest sky for at least a couple of hours after sunset.

Both shine with a silvery-white luster and one — Venus — appears considerably brighter. And especially noticeable over the course of recent nights is that they seem to be drawing closer to each other. In fact, at this moment in time, from our earthly viewpoint, they literally are like two celestial ships passing in the night. Jupiter will appear about one-seventh as bright as Venus.

On June 7, the two planets will appear side-by-side as they descend toward the horizon, with Jupiter on the left and Venus on the right. They'll be separated by 2.3 degrees. On June 8, Venus will have moved to the upper right of Jupiter, the gap between them having been reduced to 1.8 degrees.

As we have just noted, the two planets will appear closest on June 9. The actual closest approach, with Venus sliding just 1.6 degrees above (north) of Jupiter, will take place at 12 hours Universal Time (UT), which is during the daytime for North America. At that time, just over three times the apparent width of the full moon will separate these two planets. Nonetheless, even though they will already be in the process of slowly separating as darkness falls later that evening, the two planets will still appear practically as close as they were just hours before.

Thereafter, Jupiter will appear to drop rapidly away from Venus, setting progressively earlier and becoming more and more deeply immersed in the bright evening twilight during the balance of June. It will likely disappear in early July.

Venus, on the other hand, reaches its highest altitude in the western evening twilight during June for this current apparition and captures the gaze of millions. All through June, it will appear each evening more than 25 degrees high in the west right after sunset and will not drop below the horizon until at least 2.5 hours later. During this time, Venus will be setting unusually late in the evening, not disappearing beyond the west-northwest horizon until after 11 p.m.

Mercury joins the lineup

While all this is taking place, a third planet will be evident below Venus and Jupiter. That third planet will be Mercury.

Mercury is often cited as the most difficult of the five bright planets to see. Called an "inferior planet" because its orbit is nearer to the sun than the Earth's, Mercury –scarcely more than half as far from the sun as Venus is — always appears from our vantage point to be in the same general direction as the sun and it's usually lost in the sunlight. Yet it's not really that hard to see. You simply must know when and where to look and find a clear horizon.

And for those living in the Northern Hemisphere, a great "window of opportunity" for viewing this rocky little world in the evening sky has just opened. That window, in fact, will remain open through at least June 22, giving you an ample number of chances to see this so-called "elusive planet" with your own eyes.

Currently, Mercury is visible about 45 minutes after sunset. You can use Venus to guide you to Mercury. Just look low toward the west-northwest horizon and you'll readily see Venus shining brightly in the twilight sky. Then look about 15 degrees below and to the right of Venus — your clenched fist held at arm's length measures 10 degrees. Much fainter Mercury will be roughly "one and half fists" from Venus and will be shining with just a trace of a yellowish-orange tinge.

And Mercury will be shining at a very respectable magnitude of -0.2, rivaling orange Arcturus, the fourth brightest star in brilliance. Venus, however, will appear some 33 times brighter.

In the evenings that follow, Mercury will slowly diminish in brightness, but it will also slowly gain altitude as it gradually moves away from the vicinity of the sun. It will achieve its greatest eastern elongation — its greatest angular distance when it will be 25 degrees removed from the sun at magnitude +0.4 — on June 15.

By the evening of June 23, Mercury's brightness will have dropped to magnitude +1.3, equal to the star Regulus in Leo; only one-quarter as bright as it was on June 5. In telescopes, it will appear as a narrowing crescent phase. This will probably be your last view of it. Thereafter, the combination of its lowering altitude, plus its descent into a much-brighter sunset glow, should finally render Mercury invisible. It will pass through inferior conjunction — between the sun and Earth — on July 12.

Enter Gemini's twin stars

Amidst this planet array is a pair of bright stars: Pollux and Castor. They are often considered winter stars, though they remain evident in the west-northwest sky well into the spring. They are the brightest stars in the zodiacal constellation of Gemini, the Latin word for "twins." The two stars represent their heads.

Pollux is slightly brighter (1st magnitude with a slight orange-yellow color) and Castor (2nd magnitude, white). They are a scant 4.5 degrees apart, making good measuring points. In telescopes, Castor is more interesting: it is one of the many "double" stars in the sky. As a matter of fact, it's a triple star, and each of its three components is a double star (six in all!). Through it all, the Twins serve as bystanders, seemingly watching as Venus, Jupiter and Mercury scurry past them during the first three weeks of June.

The moon completes the show

The moon, our nearest neighbor in space, will join the planetary/stellar parade during the third week of June. On June 16, it will appear as a slender sliver of light, just two days past new phase and sitting a little less than 3 degrees above Mercury and 5 degrees to the lower right of Jupiter. Then on June 17, the slightly wider lunar crescent will appear just a couple of degrees to the left of brilliant Venus; the two brightest objects in the night sky adorning the west-northwest evening sky.

Here is a chance to see for yourself that nearby solar system objects generally seem to move faster than more distant ones. Indeed, on June 16 and June 17, as darkness falls, we will have a configuration laid out before us consisting of the moon at 224,000 miles (361,000 km) from Earth; Mercury at 75 million miles (120 million km); Venus at 107 million miles (171 million km) and Jupiter at 568 million miles (914 million km). The motion of the moon can be detected with the naked eye in less than an hour, that of Mercury and Venus from night to night, but Jupiter's travel among the background stars is not very noticeable in even a week. In small telescopes, each object has high interest: Mercury and Venus for their phases, Jupiter for its cloud belts and four Galilean satellites, and finally the moon for its rich surface detail.

The planets in the night sky are always shifting in and out of celestial liaisons and a wide variety of different conjunctions and configurations typically occur during any given year. It is highly unusual, however, when three or more bright planets appear to reside in the same area of the sky. So, in the evenings ahead, everyone should make a concerted effort to go out and look, since similar planet gatherings will be few and far between in the future.

Incidentally, the next time such a favorable June gathering of Mercury, Venus and Jupiter along with Pollux and Castor and the crescent moon occurs again won't come until the year 2085! In fact, on June 14 of that year, those three planets will form an eye-catching compact triangle less than 2 degrees wide.

Mark your calendars.

If you're looking for a telescope or binoculars to observe the night sky, our guides for the best binocular deals and the best telescope deals can help. Our best cameras for astrophotography and best lenses for astrophotography can help you get ready to capture the next stunning skywatching event.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, Sky and Telescope, The Old Farmer's Almanac and other publications.

A single colossal impact may have rapidly spread water across Mercury and locked much of it into permanently shadowed polar craters — all within the span of a single Mercurian day, or 176 Earth days, according to a new study.

Being the closest planet to the sun, Mercury seems like the last place in the solar system where water ice should survive. The sun appears nearly three times larger in Mercury's sky than it does from Earth, while daytime temperatures on the scorched world can soar above 800 degrees Fahrenheit (427 degrees Celsius).

Yet observations from Earth-based telescopes in the 1990s, later confirmed by NASA's MESSENGER spacecraft, revealed vast pockets of frozen water hidden inside deep craters near Mercury's poles that never receive direct sunlight. Exactly how that ice formed, however, has remained a mystery.

One leading hypothesis suggests the polar ice was delivered during a relatively recent impact by a water-rich comet or asteroid — possibly in scale and age to the one that carved Hokusai crater, a prominent 60-mile-wide (97-kilometer-wide) crater in Mercury's northern hemisphere. Hokusai is known for its bright rays of debris that stretch thousands of kilometers across the planet, created when material blasted from beneath Mercury's surface was hurled outward during the impact.

"How is water transported and redistributed in the aftermath of an impact on Mercury?" the researchers write in the new paper. "The results presented here indicate that the answer depends in part on the scale of the impact."

To investigate the idea that much of Mercury's present-day ice may have been delivered by a large, volatile-rich collision, a team co-led by scientist Parvathy Prem of Johns Hopkins Applied Physics Laboratory in Maryland ran computer simulations recreating a Hokusai-like impact.

The simulated collision matched a roughly 17-kilometer-wide impactor slamming into Mercury at speeds of up to 30 kilometers per second, generating a dense, temporary atmosphere rich in water vapor around the planet, the team reports in the new study.

"Within just over an hour after impact, the impact-generated water vapor has expanded to entirely surround the planet," the study notes, adding that "the bulk of ice deposition occurs within one solar day (176 Earth days)."

The surprisingly rapid spread of water was possible because the dense, impact-generated atmosphere effectively protected itself from the sun's intense ultraviolet radiation, according to the study.

The temporarily thick cloud of water vapor acted like a shield, the researchers say, slowing the breakdown of water molecules and allowing much larger amounts of water to survive long enough to migrate into Mercury's permanently shadowed polar craters.

The findings suggest Mercury's ice was deposited rapidly rather than supplied gradually over long periods of time — a scenario that also helps explain the apparent purity of the ice deposits, the study notes.

Scientists hope upcoming observations from the joint European-Japanese BepiColombo mission will provide new clues about the origin of Mercury's polar ice. The $1.8 billion spacecraft — only the second mission ever sent to orbit Mercury after MESSENGER — experienced an 11-month delay after a thruster glitch forced engineers to redesign part of its trajectory to compensate for reduced thrust.

BepiColombo is now scheduled to enter orbit around Mercury in November, when the mission's two probes will separate and begin studying the planet from different orbits.

This research is described in a paper published May 12 in the Journal of Geophysical Research: Planets.

Look west after sunset tonight (May 21) to see the crescent moon shining alongside the Beehive Cluster in the constellation Cancer, while Jupiter, Venus and elusive Mercury line up nearby in the evening sky.

The silvery curl of the crescent moon will hang low over the western horizon as the sun slips from view, less than 5 degrees to the upper left of the Beehive star cluster, which is also known as Messier 44, or Praesepe.

Jupiter will shine brightly about 20 degrees to the lower right of the moon, while Venus and Mercury form a diagonal line beyond. Mercury — the lowest of the planetary trio — will sit less than 5 degrees above the horizon. You'll need a clear view to the west, but even then you may struggle to spot it in the yellow glow of the retreating sun.

Both the moon and the Beehive Cluster will fit neatly in the field of view of a pair of 10X50 binoculars, which help reveal the brightest of its young stars in the waxing glow of the 36%-lit lunar disk.

A small backyard telescope will bring a plethora of diverse craters and dark lunar seas into view. Look out for Theophilus crater, which sits close to the line separating night from day — known as the terminator — and the Piccolomini impact site, which scars the lunar surface further to the south.

Both craters feature prominent central peaks formed from rock that rebounded inwards following the violent impact that heralded their creation. Their terraced eastern walls will also appear filled with shadow on May 21, making for a dramatic sight.

The moon will gently drift away from M44 as the hours wear on, before finally setting below the horizon in the early hours of May 22.

Interested in capturing glorious photos of the night sky for yourself? Then be sure to read our beginner's guide to photographing the night sky, along with our picks of the best lenses and cameras for astrophotography.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Astronomers using the James Webb Space Telescope have, for the first time, directly analyzed the surface of a planet beyond our solar system,

The James Webb Space Telescope's (JWST) exoplanet subject, LHS 3844 b, is a so-called "super-Earth" about 30% larger than our planet and located nearly 50 light-years away. Unlike most exoplanet studies, which focus on atmospheres, astronomers analyzed heat emitted from this planet's surface.

The findings reveal a dark, airless world that may resemble Mercury. Scientists say this kind of direct interpretation of a distant planet's geology marks "the next step in unveiling their nature."

"Thanks to the amazing sensitivity of JWST, we can detect light coming directly from the surface of this distant rocky planet," Laura Kreidberg of the Max Planck Institute for Astronomy in Germany, who served as the principal investigator of the JWST observations, said in a statement. "We see a dark, hot, barren rock, devoid of any atmosphere."

Discovered in 2019, LHS 3844 b orbits a cool red dwarf star in just 11 hours and is tidally locked, meaning one side constantly faces the star while the other remains in darkness. The dayside reaches temperatures of about 1,340 degrees Fahrenheit (725 degrees Celsius), the scientists say.

In 2023 and 2024, Kreidberg and her team observed three secondary eclipses, when the planet moved behind its star. Using the JWST's Mid-Infrared Instrument (MIRI), they measured the infrared light emitted from the planet's intensely hot dayside and used it to study its surface.

By comparing the signal with known rocks and minerals from Earth, the moon and Mars, the team ruled out an Earth-like crust rich in silica and granite. Such crusts typically form through water-driven geological processes and plate tectonics, which recycle rock and allow lighter minerals to rise to the surface, the study notes.

Instead, the data point to a surface dominated by basalt, a dark volcanic rock rich in iron and magnesium commonly found on the moon and Mercury, the researchers say.

"This planet likely only contains little water," study lead author Sebastian Zieba of the Center for Astrophysics, Harvard & Smithsonian in Massachusetts said in the statement.

One possible explanation, the researchers say, is that LHS 3844 b has a relatively young surface shaped by recent volcanic activity, where fresh lava has not yet been broken down by micrometeorite impacts. However, such activity is known to release gases such as carbon dioxide or sulfur dioxide, which were not detected by MIRI, the study notes.

"If present on LHS 3844 b in reasonable amounts, MIRI should have detected it," the statement read. "Still, it found nothing."

Alternatively, the planet may be covered in a thick layer of dark, fine-grained material formed over long periods by radiation and meteorite impacts, similar to the moon or Mercury. Without an atmosphere, the surface would be especially vulnerable to this process, known as space weathering, which gradually breaks down and darkens rock.

"This alternative relies on longer periods of geological inactivity, thereby requiring conditions opposite to the first scenario," the statement read.

Follow-up JWST observations are planned to further refine the planet’s surface properties and determine whether it is solid rock or loose, weathered material, the study notes.

"We are confident the same technique will allow us to clarify the nature of LHS 3844 b's crust and, in the future, other rocky exoplanets," Kreidberg said in the same statement.

A study about these results was published Monday (May 4) in the journal Nature Astronomy,

The April new moon has arrived bringing several nights of spectacular dark skies perfect for observing the planets of the solar system, majestic constellations and the galaxies that lie beyond.

April's new moon occurs at 7:52 a.m. EDT (1152 GMT) on April 17, when the moon is positioned between the sun and Earth, rendering it lost from sight in the daytime sky, with the entirety of its near side bathed in shadow.

The moonless nights surrounding this phase are the perfect time to indulge in skywatching and night sky photography, as subtle constellations and deep sky objects often lost behind a veil of moonlight glisten in the twilight realm.

Visible planets

Look to the west shortly after sunset on April 17 to find Venus appearing as a bright evening star 15 degrees from the horizon, with the blue-white stars of the Pleiades open star cluster glowing 10 degrees above — roughly the width of your clenched fist held at arm's length.

The ice giant Uranus can be found a little under 5 degrees to the lower left of the star cluster. It'll be too dim to spot with the naked eye — without exceptionally dark skies and perfect vision — but a pair of binoculars or a small telescope will allow you to spot its disk as a tiny greenish dot, according to telescope manufacturer Celestron.

Jupiter, meanwhile, will shine high overhead, below Castor and Pollux — the brightest stars of the constellation Gemini. Turn a 6-inch telescope on Jupiter and you may notice a line of bright dots extending outward from the gas giant's colorful disk. Those are the Galilean moons Io, Ganymede, Europa and Callisto!

Head out an hour before sunrise on April 18 and find yourself a clear view to the eastern horizon for a chance to catch a planetary triangle rising in the glow of the coming dawn.

Mars will sit higher in the sky,with Saturn below and Mercury off to the right. Neptune will also be present to the upper right of Mercury, though the distant ice giant will be far too dim to spot with the naked eye.

Stars and constellations

The dark nights surrounding the new moon are a perfect time to explore some of the subtler constellations that glisten in the northern hemisphere sky.

First, locate the sickle-like formation of stars representing the head and chest of the great lion represented in the constellation Leo, which can be found high above the southern horizon in April with the bright star Regulus at its base.

Next, look to the lower right of Regulus to find a circlet of stars representing the head of the great serpent in the constellation Hydra, along with a string of stars that wind down and to the east towards the horizon, which mark its tail. Hydra is the largest constellation in the night sky, though it's often overlooked due to its lack of bright stars.

Perched along Hydra's back are the compact constellations Corvus (the crow) and Crater (the cup). To their east is the blue-white light of Spica — the brightest star in the constellation Virgo.

For a spot of deep sky viewing, why not head out to a dark sky location and sweep your telescope over the patch of sky where Leo, Virgo and the constellation Coma Berenices meet?

First, find Denebola, the star that marks the tail of the lion in Leo, and Vindemiatrix using a handy stargazing app. Roughly halfway between the two is Markarian's Chain — a spectacular string of galaxies whose ancient light can be spied with the aid of a modest telescope.

Read more: Galaxy season: Spring brings deep space wonder to the northern hemisphere night sky.

You could also capture spectacular images of the stars with the help of our beginner's guide to photographing the night sky. Be sure to check out our picks of the best telescopes and binoculars for exploring the night sky, along with our roundups of the top cameras and lenses for astrophotography available in 2026.

Editor's Note: If you would like to share your night sky photography with Space.com's readers, then please send your photo(s) along with your name, location and comments to spacephotos@space.com.

Jupiter, Saturn, Venus, Neptune, Uranus and Mercury are staring in a "planetary parade" this week, but your ability to actually spot them will depend on preparation, equipment and, as always, a spot of luck with the weather.

Most of this week's naked-eye planetary action will take place low in the western sky, which is where the aforementioned preparation comes in. Be sure to stake out a raised location with a clear view of the horizon well ahead of time — you can use a smartphone stargazing app to figure out exactly where the planets will be in your local environment, so there's no need to guess.

Do so, and you'll be granted a rare, if challenging opportunity to spot Mercury shining 10 degrees — roughly the width of your clenched fist held at arm's length — above the late winter skyline, with Venus close to its left, floundering in the glow of the setting sun. Saturn, meanwhile, will glow less than 10 degrees to the upper left of Venus, with a distant cousin lurking nearby, but more on that later.

Mercury and Venus will follow the sun out of sight roughly an hour after sunset, briefly becoming more visible as the sky darkens and they grow closer to the horizon. Jupiter, meanwhile, will shine high in the eastern sky, with the waxing gibbous moon below, obscuring the stars of the constellation Cancer with its reflected light.

The next two planets will need a little added magnification to spot — and even then, you'll have the odds stacked against you.

The ice giant Neptune will be positioned two degrees to the right of Saturn, but will be too dim to spot with the unaided eye. Under dark skies, a telescope with an aperture of 8 inches (200 millimeters) or more can reveal its tiny bluish disk. However its position low on the horizon and close to the glare of our parent star will make it a challenge to spot on the nights surrounding Feb. 28. As always the utmost care must be taken to ensure that the sun is firmly below the horizon before pointing telescopic equipment in its general direction.

Uranus, meanwhile, can be found by sweeping your scope across the patch of sky 5 degrees below the Pleiades open star cluster, to the right of the "V" formation of stars in the constellation Taurus in the hours following sunset. Again, those new to the night sky may want to use a smartphone astronomy app, which makes use of augmented reality technology to help you pinpoint everything from constellations and planets to galaxies and meteor shower radiants.

Award-winning night sky photographer Josh Dury grappled with the sheer scope of the scene along with the glow of the setting sun and other challenges to capture a gorgeous long exposure view of the planetary parade earlier this week as it brightened the sky over the south of England.

For more, check out our handy guide on the equipment needed to see and photograph the planets. If you're into photography, then why not also read our roundups of the best cameras and lenses for capturing the night sky?

Editor's Note: If you would like to share your planetary astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

If there is one thing that has bothered me over my nearly 60-some years as an amateur astronomer, it is the way that most astronomy books give the impression that the planet Mercury is very difficult, if not almost impossible, to see. It has, in fact, earned this planet the nickname of the "Elusive Planet."

Here, for example, is a passage taken from the book "All About the Planets," by Patricia Lauber (Random House, NY 1960):

"Mercury is difficult to study because it is a small planet that lies between us and the sun. Most of the time, it is hidden by the sun's glare. It never crosses our night sky but appears for short periods just after sunset and just before sunrise. It can be seen only if the sky is very clear."

This certainly doesn't sound very inviting for someone who might want to try and see Mercury for themselves. And yet, the viewing prospects are not as grim as this passage suggests. In fact, on certain occasions, Mercury is not so elusive at all. You simply must know when and where to look and find a clear horizon. It is important, for instance, that Mercury be positioned as directly above the sun's place as possible, a condition that is best fulfilled just after sunset in the late winter or early spring and before sunrise in autumn or early winter.

And for those living in the Northern Hemisphere, just such a "window of opportunity" for viewing Mercury in the evening sky is about to open. In addition, it will also be very near to a slender waxing crescent moon on Feb. 18, which can serve as a benchmark for making a positive identification of this, the smallest and innermost planet to the sun.

Bright and accessible

On Feb. 6, Mercury begins its best evening apparition of the year for viewers at mid-northern latitudes. Although only 12 degrees from the sun, this little planet shines as bright as -1.1 magnitude (nearly as bright as Sirius, the brightest star), albeit it is quite low in the west and only setting about 55 minutes after the sun. On each of the next 13 evenings, however, Mercury gets progressively higher and sets a bit later.

If your sky is clear and there are no tall obstructions to your view of the western horizon (like trees or buildings), you should have no trouble seeing it as a very bright "star" shining with just a trace of a yellowish-orange tinge.

By Feb. 19, Mercury attains its greatest elongation (maximum angular separation), 18 degrees from the sun. What is notable for observers near latitude 40 degrees north is that almost all this separation is vertical: Mercury stands nearly 17 degrees above the horizon at sunset. Also on that evening, this rocky little planet does not set until after the end of astronomical twilight — in other words, in a dark night sky. Shining at magnitude -0.4 (brighter than the star Arcturus, in the constellation of Boötes), Mercury sets more than 1½ hours after the sun, making this its best evening appearance of 2026.

Lunar courting

As noted earlier, on the evening of Feb.18, Mercury will keep close company with a slender waxing crescent moon. About 45 minutes after sunset on that evening, look low toward the west-southwest to sight the moon, only 1½ days past new phase and 2 percent illuminated. It will mimic the smile of a celestial Cheshire Cat. And hovering very closely, directly above it, you'll see a very bright "star," which will be Mercury. And if you live in Texas, Arkansas, Louisiana, Mississippi, Alabama, Georgia or Florida, you might even get a chance to glimpse the moon passing directly in front of Mercury at around 7:37 p.m. EST/6:37 p.m. CST. Binoculars will enhance this very striking view against the fading twilight sky, a beautiful celestial tableau. You'll be surprised how easy it will be to sight the "elusive planet."

Finally, the denouement: Mercury drops rapidly and fades quickly, ultimately vanishing into the sunset fires.

Phase diminishes = Fade out

Mercury, like Venus, appears to go through phases like the moon. When February began, its disk was 97 percent illuminated by the sun, imparting the appearance of an almost fully illuminated disk in telescopes, which is also why it starts the month appearing so bright. Telescopes show Mercury 50 percent illuminated when it arrives at greatest elongation, and in the following days, its rapidly decreasing phase results in a dramatic loss in brightness. Whereas the planet burns at -0.4 magnitude on Feb. 19, by Feb.24 it has faded more than a whole magnitude, to magnitude +0.6 and soon afterward it is lost in the bright twilight sky.

In fact, just two days later, on the evening of February 26, Mercury's brightness will have dropped to magnitude +1.3, just a trifle brighter than the star Regulus in Leo; only about one-fifth as bright as it was on Feb. 19. In telescopes, it will appear as a slender crescent phase, 17% illuminated by the sun. My guess is that Feb. 26 will probably be your last chance to see it. The combination of its lower altitude, plus its descent into the much-brighter sunset glow, should finally render Mercury invisible during the final days of February. It will pass through inferior conjunction — between the sun and Earth — ending its evening run, on March 7.

The two planets that are in prime position for evening visibility this month are, ironically, the two planets on opposite ends of the spectrum concerning size. The solar system's biggest planet, Jupiter, is in excellent position for observation this month of February, high in the east-southeast sky at nightfall and soaring high into the sky during the mid-to-late evening hours. Meanwhile, the smallest planet — Mercury — will enjoy its finest evening apparition, readily available to those who seek it out about three-quarters of an hour after sunset, low in the west-southwest sky, for a three-week interval beginning on Feb. 6.

There are two other planets in the evening sky: Saturn is also in the west-southwest sky, but getting progressively lower with each passing day. The combination of low altitude and increasingly bright twilight will make it rather difficult to sight during the final week of the month. If only Saturn were a bit brighter, it would be easier to see. Which is why dazzling Venus, in the same general vicinity as Mercury and Saturn, will slowly emerge into prominence during the last half of February and on into March.

The only planet completely out of the viewing loop is Mars, which is much too close to the glare of the sun to be seen all month long.

In our schedule, remember that when measuring the angular separation between two celestial objects, your clenched fist held at arm's length measures roughly 10-degrees. Here, we present a schedule below which provides some of the best planet viewing times, as well as directing you to where to look to see them.

Mercury

Mercury, moving from superior conjunction, begins a fine apparition on the evening of Feb. 6, low in the west-southwest for skywatchers at mid-northern latitudes. During the first part of February, it comes into view higher in the fading dusk each evening. Currently, magnitude -1.1 (among the stars, only Sirius is brighter), and 12 degrees east of the sun, the planet will set an hour after sundown. On the evening of Feb. 18, about 45 minutes after sunset, look low toward the west-southwest horizon for a hairline-thin waxing crescent moon, just 2 percent illuminated by the sun. Sitting less than one degree above it will be Mercury. The pair is even closer together as seen from the Midwest and still closer together as seen from the western U.S.

The view through binoculars should be stunning. As a bonus, for parts of Texas, Arkansas, Louisiana, Mississippi, Alabama, Georgia and Florida, the moon will appear to pass directly in front of Mercury. On the following evening, Mercury attains its greatest elongation, only 18.1 degrees from the sun. So small an angle for an eastern elongation will not be matched until 2039. And yet around this time Mercury will be in the sky throughout evening twilight, the only such occasion in 2026. At this time, the speedy little planet shines at magnitude -0.4, and telescopes show its tiny disk exactly half lit — which isn't always the case at most of Mercury's greatest elongations. In the following week, Mercury fades by nearly a factor of five and soon sinks out of view. Inferior conjunction occurs on March 7.

Venus

Venus was at superior conjunction with the sun on Jan. 6; farthest from Earth on Jan. 8; and at aphelion — farthest from the sun in space — on Jan. 22. As February begins, Venus will be very challenging to glimpse even with optical aid, for it will be less than 4 degrees high at sunset and will set less than a half hour after the sun.

By Feb. 15, Venus may be evident to the eye without any optical aid. About 15 minutes after sunset, search very low near the west-southwest horizon. If you still can't find it, scan with binoculars, then once found, you should be able to see it with your unaided eyes shining radiantly through the bright evening twilight. On the other hand, by month's end, this brilliant -3.9-magnitude planet appears about 10 degrees high at sunset and should be reasonably easy to find before it sets about an hour after sundown.

Mars

Mars during February lies only 6 to 12 degrees west of the sun and, as such, is hopelessly lost in the solar glare.

Jupiter

Jupiter was at opposition on Jan. 10. So, February finds it already well up in the east as the sky darkens. It shines in Gemini, dimming a bit this month from magnitude -2.6 to -2.4 as it slowly retrogrades (moves westward relative to the background stars). The big planet is high for most of the night as seen from mid-northern latitudes; it's highest around 10:20 p.m. as February begins and 8:30 p.m. as the month ends. And although its apparent diameter shrinks slightly by about 6% during this month, Jupiter always appears large enough through a medium-sized telescope to see a lot of detail in its clouds if the air is sufficiently steady. As darkness falls on Feb. 26, look high in the eastern sky for the waxing gibbous moon and hovering about a half-dozen degrees below it will be "Big Jupe."

Saturn

Saturn is losing altitude rapidly with each passing night. At the beginning of the month, it's visible low in the west-southwest sky as darkness descends. Now Saturn's lower position will make locating it trickier, so tonight, use the moon as your benchmark. In telescopes, the still-narrow rings will be slowly opening like some late-winter flower, but by month's end, it will be difficult to get an image of them unruffled by Earth's quavering atmosphere. The crescent moon, which on Feb. 19 will have widened to 7% illuminated after its close encounter with Mercury on the previous evening, will sit about 4 degrees to the right of first-magnitude Saturn.

Jupiter, the largest planet in the solar system, currently shines as a brilliant silvery "star" in Gemini the Twins, low in the east-northeast sky as dusk slowly fades. It forms an eye-catching scalene triangle configuration with the "Twin Stars" Pollux and Castor; you really can't miss it.

And at 4 a.m. EST (0900 GMT) on Saturday (Jan. 10), Jupiter will arrive at that point in the sky directly opposite to the sun, called "opposition." If all the planets' paths around the sun were true circles, this would also coincide with Earth's closest approach to Jupiter, 393.3 million miles (632.9 million kilometer). That, however, occurs 25 hours earlier, at 3 a.m. EST (0800 GMT) on Friday (Jan. 9).

Opposition occurs when Earth, moving faster in its orbit than Jupiter, overtakes the giant planet. In the four months centered on each opposition, Jupiter appears to swirl backward in a loop against the background stars. After opposition, we will leave Jupiter behind. Jupiter is also currently moving away from the sun on its own elliptical path, while, less than a week ago, Earth passed its closest point to the sun (perihelion).

Jupiter will reach its farthest point from the sun — its aphelion point, which takes it 507 million miles (815.7 million km) from our star — on Dec. 28, 2028.

'Big Jupe' almost became a star

Jupiter constantly is the most interesting object in the solar system after the moon and the sun and has always held a special place in the hearts of telescope viewers. Jupiter provides telescope users with a feast of features: a restless atmosphere and a retinue of bright satellites.

This giant planet — which has nearly 2.5 times more mass than all of the other planets put together — takes nearly 12 Earth years to go once around the sun. Thus, it spends roughly a year within each of the 12 zodiacal constellations, since the constellations are of unequal width.

With an equatorial diameter of 88,846 miles (142,984 km), Jupiter is the largest planet: a colossal ball of hydrogen and helium without a solid surface. Scientists are currently uncertain about the exact nature of Jupiter's core, but modern data suggests it is not the solid, compact rocky ball once imagined. Recent findings from NASA's Juno mission and updated scientific models suggest that, instead of a sharp boundary between a solid core and the rest of the planet, Jupiter likely has a "dilute" core. This means that heavy elements like rock and metal are dissolved and encased in a thick mantle of metallic hydrogen enveloped in a massive atmospheric cloak of multi-colored clouds of ammonium hydrosulphide.

And, in a strange sense, Jupiter might even be referred to as a stillborn star, for it has the makings (mostly hydrogen) if not the mass of a stellar body. Its relative smallness, however, prevents the initiation of the nuclear processes that could have turned it into a full-fledged star. Had Jupiter been born a bit bigger, we would have the distinction of living within a binary star system.

Cloud bands and satellites

Binoculars show Jupiter as a tiny disk, while a medium-size telescope reveals numerous dark belts, light zones and a wealth of festoons, garlands, ovals and other features extending here and there. Jupiter's rotation is the fastest of all the solar system's planets. It completes a rotation on its axis in slightly less than 10 hours, which creates an equatorial bulge easily perceived through most telescopes. And January offers nearly optimum views of its intricate cloud features; it's even possible at mid-northern latitudes to observe every longitude of the planet during the long night.

Besides its prominent cloud belts, Jupiter's greatest telescopic treasure are its four Galilean moons that run a merry race with each other around the planet, changing their respective positions from hour to hour and night to night. The smallest of telescopes – even steadily held 7-power binoculars – will reveal these four bright satellites of Jupiter as tiny stars nearly in line and changing their places in the line as they revolve around the planet in orbits nearly edgewise to us. Typically, at least two or three are visible at any given moment.

On Saturday (Jan. 10), for example, we will see three satellites on one side of Jupiter (going outward from the planet: Ganymede, Io and Europa), while the fourth (Callisto) remains all by itself on Jupiter's opposite side.

Coming attractions

Jupiter will appear to climb higher in the evening sky in the weeks to come. Currently, the giant planet is ready for telescopic observation by 7 p.m., when it will stand one-third of the way up from the eastern horizon to that point directly overhead (called the zenith). It reaches its highest position in the south around midnight and is heading toward its setting in the west during dawn. After the glory of its opposition on the midnight meridian, Jupiter will appear a bit higher in the east each evening and will engage its stellar neighbors, Pollux and Castor in a sort of celestial pas de trois in the coming weeks.

On the evening of Feb. 27, the scalene triangle will have changed into a narrow isosceles, and nearly aligned with Pollux and Castor will be a waxing gibbous moon. But the real show occurs in late May and early June, when a fascinating dance of three planets and the moon will provide evening enchantment. On the evening of May 20, a crescent moon will be positioned well to the upper left of Jupiter. During the final week of May, one hour after sunset, you can watch how Venus climbs to meet Jupiter. On June 9, they'll call attention to themselves low in the west-northwest sky. Finally, on June 16, a slender crescent moon will appear to the right of Jupiter, and below the moon will sit yet another planet, Mercury.

The heavenly ballet continuously being performed by these "wandering stars" has played a crucial role in the celestial lore of all people. It is not surprising that they were regarded as deities. The five naked-eye planets (Mercury, Venus, Mars, Jupiter and Saturn) have been known since antiquity, and it is also interesting that the members of this quintet have all been examined closely by space probes. Of course, before the advent of the telescope, virtually all peoples regarded planets as a special category of star.

Over the following month, Jupiter sinks into the sun's glare. Emerging into the morning sky of August, he will progress into the constellation of Cancer the Crab, and on Sept. 24 he will cross over into the western boundary of Leo the Lion, where he will remain for the balance of the year. A spectacular eclipse (occultation) of Jupiter will await early risers across much of North America on Oct. 6, and a brightening Mars will closely pass north of Jupiter on Nov. 16. On Dec. 13, Jupiter will begin to swirl backward into the next loop that will climax in the opposition of Feb. 10, 2027.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, Sky and Telescope and other publications.

Want to know when each planet will be at its best or when you can catch eye-catching planetary pairings in 2026?

This guide breaks down the major planetary events of the year, from conjunctions to oppositions to close planet-star encounters.

Related: Night sky tonight live blog

Mercury

Mercury, the smallest of the planets visible to the naked eye, appears as an evening star in the western sky, setting about an hour after the sun. As a morning star, it rises about an hour before the sun in the eastern sky. To view the planet, a clear, unobstructed view of the horizon is essential. Mercury usually appears as a bright "star" with a yellowish or ochre tint.

Visibility windows in 2026

• Evenings: Feb. 5–26; June 1–22; Sept. 28–Oct. 19
• Mornings: March 27– April 17; July 26– Aug. 16; Nov. 13– Dec. 4

When will it be at its best?

• Evening: Feb. 5–26
• Morning: Nov. 13– Dec. 4

On the evening of Feb. 18, about 30 minutes after sunset, Mercury will sit just 1 degree above a slender waxing crescent moon low in the west-southwest.

Venus

Venus, with its nearly circular orbit and a diameter only 400 miles (640 kilometers) smaller than Earth's, shines with a brilliant, steady silvery light.

Visibility windows in 2026

• Evenings: March 8– Oct. 14
• Mornings: Nov. 3– Dec. 31

When will it be at its best?

Venus reaches greatest brilliancy in the evening sky on Sept. 19 and in the morning sky on Nov. 29. In late September through mid-October, and again through most of November, Venus will show a striking crescent phase in telescopes and steady binoculars.

Notable conjunctions:

• March 8: Venus passes 1 degree to the upper right of Saturn.
• June 9: Venus passes 1.6 degrees to the upper right of Jupiter — a brilliant sight in the west-northwest 45 minutes after sunset.
• Nov. 7 (morning): Shortly before sunrise, look low to the east-southeast for Venus, a crescent moon, and the star Spica, all fitting within 2.5 degrees.

Mars

Mars, long associated with Ares, the Greek god of war, shines like a star with a yellowish-orange hue and can vary considerably in brightness.

Visibility in 2026

• Mornings: March 18- Dec. 31

When will it be at its best?

This is an "off" year for Mars. The planet begins 2026 lost in the sun's glare and reaches solar conjunction on Jan. 9, sitting on the far side of the solar system about 223 million miles from Earth.

Mars begins to reappear in the third week of March, rising before sunrise among the faint stars of Aquarius. It moves into Taurus for the first half of summer, shining only around magnitude +1.3.

Sky highlights:

• Sept. 25: Castor and Pollux point directly toward Mars.
• Oct. 11: Mars passes through the Beehive Cluster in Cancer — an attractive sight in binoculars.
• Nov. 26: Mars passes 1.7 degrees above Regulus in Leo, creating a dramatic color contrast.
• By late December, Mars brightens to magnitude –0.1 and will rival Arcturus in both color and brightness.
• Feb. 19, 2027: Mars reaches its next opposition, so it steadily approaches Earth late in 2026.

Notable conjunctions:

• April 20: Mars aligns closely with Saturn and Mercury.
• July 4: Mars passes just 0.1 degree south of Uranus, offering a superb guidepost for locating Uranus.
• Nov. 16: Mars passes 1.2 degrees to the upper left of Jupiter.

Jupiter

Jupiter, the giant planet with a diameter about 11 times bigger than Earth's, shines with a bright silver-white luster.

Visibility windows in 2026

• Mornings: Jan. 1–9; Aug. 19– Dec. 31
• Evenings: Jan. 10–July 7

Jupiter reaches opposition on Jan. 10 and shines brightest from Jan. 1–22 at magnitude –2.7 in Gemini. It enters Cancer on June 22 and Leo on Sept. 24, where it remains through year's end.

On June 9, Jupiter pairs with Venus in a stunning "double planet" display low in the west-northwest at dusk.

Oct. 6 lunar occultation

On the morning of Oct. 6, observers across most of North America (excluding the far West) and northern Cuba will witness a spectacular lunar occultation of Jupiter. A waning crescent moon will slide directly in front of Jupiter, hiding it for up to an hour depending on location. Jupiter disappears behind the bright limb and reemerges dramatically from the moon's dark side.

Saturn

Saturn shines as a yellowish-white "star" of moderate brightness. Its famous rings, invisible to the naked eye, turned edge-on in 2025 and were nearly impossible to see for weeks. They are now slowly opening up again.

Constellation path in 2026:

• Starts in Aquarius (to Jan. 14)
• Enters Pisces (Jan. 14– April 8)
• Moves through Cetus (April 9– June 2)
• Back into Pisces (June 3–Sept 4)
• Back into Cetus (from Sept. 5 onward)

Visibility windows in 2026

• Evenings: Jan. 1–March 8; Oct. 4–Dec. 31
• Mornings: April 12– Oct. 3

Saturn reaches opposition on Oct. 4 and is brightest Sept. 24–Oct. 9.

Notable conjunctions:

• Feb. 15: Saturn sits less than 1 degree from Neptune, though Neptune is much fainter.
• Apr. 20: Saturn aligns with Mars and Mercury.

Uranus

Uranus can be glimpsed with the naked eye under very dark skies by keen-eyed observers. At magnitude +5.6, it is easily found with binoculars; small telescopes show a tiny greenish disk.

Uranus spends all of 2026 in Taurus.

Visibility windows in 2026

• Evenings: Jan. 1–May 5; Nov. 25– Dec. 31
• Mornings: June 9–Nov. 24

Uranus reaches opposition on Nov. 25 and is brightest Oct. 24–Dec. 30.

On July 4, Uranus sits only 0.1 degree north of Mars, making Mars an ideal pointer to the seventh planet. Mars will outshine Uranus by a factor of about 158.

Neptune

Neptune remains in Pisces throughout 2026. At magnitude +7.8, it is visible only in binoculars or a telescope and appears bluish-gray.

Visibility windows in 2026

• Evenings: Jan. 1–March 6; Sept. 25–Dec. 31
• Mornings: April. 8– Sept. 24

Neptune reaches opposition on Sept. 25 and is brightest July 28–Nov. 24.

On Feb. 15, Neptune lies less than 1 degree to the upper right of Saturn, though Neptune is only about 1/525 as bright.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, Sky and Telescope and other publications.

If there ever was a planet that has gotten a bad rap for its inability to be readily observed it would have to be Mercury, known in some circles as the "elusive planet."

Mercury is called an "inferior planet" because its orbit is nearer to the sun than the Earth's. Therefore, it always appears from our vantage point to be in the same general direction as the sun. So near to the sun that it is often difficult to see with the unaided eye. In fact, Copernicus complained that he had never been able to enjoy a view of it, and this was doubtless because he lived at Frombork in northern Poland, near the Vistula River, where the sky near the horizon is often hazy owing to local mists and fog.

Nonetheless, during the first three weeks of December we will be presented with an excellent opportunity to view Mercury in the early morning dawn sky. If you've never sighted this rocky little world for yourself, you'll never get a better opportunity than right now to see it. So set your alarm clock for around 5:30 a.m. and head outside to a location with a clear and unobstructed view of the east-southeast sky.

Rise to prominence

On Nov. 20, Mercury was at inferior conjunction with the sun, passing roughly between the sun and our Earth. Four days later on Nov. 24, Mercury passed just one degree north of brilliant Venus, but the pair were only 10 degrees from the sun and rising about 50 minutes before sunrise, shining at a magnitude of +2.4. Mercury was still impossible to see through the brightness of dawn.

But only three days later on Thanksgiving Day (Nov. 27), Mercury was rising 75 minutes before the sun and increased by a factor of 3.6 times in brightness to magnitude +1.0. It was then fairly easy to locate, close to the east-southeast horizon about an hour before sunrise.

Mercury's visibility continued to improve rapidly and by Friday morning, Dec. 5 it will rise shortly before morning twilight begins — in a dark sky — and will have brightened markedly to magnitude -0.3. Now all you have to do is just look low above the east-southeast horizon from 40 to 80 minutes before sunrise for a bright yellowish-orange "star."

An unusually favorable greatest elongation occurs on Sunday, Dec. 7, even though Mercury is only 21 degrees from the sun. At magnitude -0.4 (among the stars only Sirius and Canopus are brighter), it rises in a dark pre-twilight sky about one hour and 50 minutes before the sun. In the 2025 Observer's Handbook of the Royal Astronomical Society of Canada, Alister Ling stresses that this will be the "best morning apparition of 2025 for Northern Hemisphere observers."

Mercury, like Venus, appears to go through phases like the moon. On Thanksgiving Day, Mercury was a slender crescent, 20 percent illuminated by the sun. By Dec. 7, it will appear 62 percent illuminated and the amount of its surface illuminated by the sun will continue to increase in the days to come. So, although it will begin to turn back toward the sun's vicinity after Dec. 7, it will brighten a bit more to magnitude -0.5 by Dec. 9, which should help keep it in easy view over the next couple of weeks.

Mercury passes 5.5 degrees to the upper left of 1st-magnitude Antares on Dec. 19 but that ruddy star will only shine about one-quarter as bright as Mercury, so you'll probably need binoculars to spot it. Mercury itself will become difficult to see in bright twilight by around Christmas.

The circumstances that make it happen

There are four reasons why Mercury will be so favorably placed for viewing in the morning sky this month:

1. At sunrise in autumn, the ecliptic — the apparent path the sun, moon and planets take across the sky over the course of a year — makes a steeper-than-average angle with the horizon for Northern Hemisphere observers.
2. Since Mercury passed the ascending node of its orbit on November 18th, it is north of the ecliptic through much of December.
3. In addition, its orbital speed is near maximum, since perihelion (its closest point in its orbit to the sun) occurred on Nov. 23.
4. Around the time of inferior conjunction, Mercury is much closer to the Earth, and its angular motion relative to the sun is much greater than around superior conjunction (when it's on the far side of the sun as seen from Earth).

Exceedingly hot ... frigidly cold

In old Roman legends, Mercury was the swift-footed messenger of the gods. The planet is well named for it is the closest planet to the sun and the swiftest of the sun's family, averaging about 30 miles per second; making its yearly journey in only 88 Earth days. Interestingly, the time it takes Mercury to rotate once on its axis is 58.7 days, so that all parts of its surface experiences periods of intense heat and extreme cold. Although its mean distance from the sun is only 36 million miles, Mercury experiences by far the greatest range of temperatures: 790º F (420° C) on its day side; -270º F (-170° C) on its night side.

Planet with a double identity

In the pre-Christian era, this planet actually had two names, as it was not realized it could alternately appear on one side of the Sun and then the other. Mercury was called Mercury (Latin Mercurius) when in the evening sky, but was known as Apollo when it appeared in the morning. It is said that Pythagoras, about the fifth century B.C., pointed out that they were one and the same.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, Sky and Telescope and other publications.

Look low on the southwestern horizon at sunset on Nov. 12 for a chance to see swift Mercury close to the red light of Mars in the evening sky, but fair warning — you'll need to be quick to spot the elusive planets before they slip quickly out of sight.

Mercury will be positioned roughly 5 degrees above the horizon at sunset on Nov. 12, with Mars shining roughly 1 degree to its upper right. Remember: the width of your three middle fingers held at arm's length accounts for 5 degrees in the night sky, while the span of your little finger is the equivalent to roughly 1 degree.

Both objects will be challenging to spot in the glare of the setting sun, becoming more visible as the sun passes deeper below the horizon. As such, you'll need to find a clear view to the southwest to give yourself the best shot at seeing the planets before they set less than an hour after the sun.

Mercury will have leapt to the right of Mars by the following evening and will continue its journey westward in the nights that follow. Mars and Mercury are positioned close to the sun in November and so the utmost care must be taken not to point a telescope or binoculars in their direction until the sun is safely below the horizon. You can check sunset times for your location using the website TimeandDate.

The past month has seen Mercury and Mars perform a delicate dance, during which the innermost planet tracked a path from right to left beneath the Red Planet in Earth's sky, before appearing to retrace its steps, as its tight orbital leash brought it closer to the sun. This visual effect is known as retrograde motion and occurs in November as faster Mercury draws alongside and passes Earth in its orbit, making the planet temporarily travel east to west in our sky. Mars, meanwhile, continues its apparent 'prograde motion', moving west to east through the starfield beyond.

Both worlds will appear progressively lower on the horizon at sunset in the coming months ahead of their respective solar conjunctions, when they will be at their closest to the sun in Earth's sky — an event that will occur on Nov. 20 for Mercury and in January 2026 for Mars.

Editor's Note: If you would like to share your planetary astrophotography with Space.com's readers, then please send your photo along with any comments, your name and the location of your shoot to spacephotos@space.com.

Mercury will reach its greatest eastern elongation on Oct. 29, marking one of the best evenings to see the planet this fall as it appears farthest from the sun's glare in the twilight sky.

As the solar system's innermost planet, Mercury travels an extremely tight orbit around our parent star, with an average separation of under 36 million miles (58 million kilometers). As a result, it never appears far from the sun in Earth's sky and is only ever visible near the horizon in the hours following sunset or preceding dawn, depending on the time of year.

Mercury will reach its most distant point from the sun in its current evening appearance at 4:28 p.m. EDT (2028 GMT) on Oct. 29, when it will be separated by roughly 24 degrees from our parent star, according to the practical astronomy website in-the-sky.org. Remember, the width of your clenched fist held at arms length accounts for 10 degrees of sky.

That evening, the rocky world will appear as a bright "evening star" above the southwestern horizon at sunset for viewers in the U.S, with the stars of the constellation Scorpius to its left and Libra on its right, though they will initially be lost in the glow of the setting sun.

Mercury will have an altitude of just 7 degrees at sunset on Oct. 29, so it's best to find a viewing location with a clear line of sight to the southwestern horizon to ensure that you get a good glimpse at fleet-footed World. The planet will remain visible for less than an hour after sunset, so timing is key. Atmospheric turbulence brought about by Mercury's low position on the horizon may cause it to shimmer like a star as its light makes a prolonged journey through Earth's dense atmosphere.

Observing the planet through a telescope with an aperture of 4 inches or more under dark sky conditions will reveal the moon-like phases of the distant world, though utmost care must be taken to ensure that the sun is safely below the horizon before pointing telescopic equipment in its direction. Mercury currently has the appearance of a waxing gibbous moon, with its right side lit by direct sunlight and its left bathed in shadow.

Stargazers hoping to get a closer look at Mercury should check out our roundups of the best telescopes and binoculars for observing the planets. Those new to exploring the night sky should also read our guide to the top smartphone astronomy apps, which can help pinpoint the locations of stars, galaxies and a treasure trove of other deep sky and solar system objects using augmented reality technology.

Look to the southwestern horizon at sunset on Oct. 23 to see the slender form of the crescent moon shine close to Mercury and Mars in the evening sky.

The 6%-lit waxing crescent moon will be visible roughly 5 degrees above the horizon as the sun sets on Oct. 23, with Mercury appearing as an "evening star" to the upper right of its sickle-like form and the red light of Mars shining just beyond, to form a cosmic lineup in the evening sky.

All three worlds will lie within 10 degrees of each other — roughly the width of your clenched fist held at arm's length against the night sky — with Mercury and Mars close enough to comfortably share the field of view of a pair of 10x50 binoculars. But remember - even just glancing at the sun with a pair of binoculars can lead to permanent loss of vision. Be sure to use a trusted website like TimeandDate to check sunset times for your locale and ensure that our parent star is well below the horizon before attempting to view the moon beside these planets with a magnifying aid.

The razor-thin form of the crescent moon will make for a challenging target to spot against the glow of the setting sun on Oct. 23, just two days out from its new moon phase on Oct. 21. The moon, Mercury and Mars will set less than an hour after the sun, so be sure to stake out a vantage point with a clear view of the southwestern horizon to ensure a good view of the solar system parade.

Mercury's tight orbit around the sun will see it depart Mars to travel leftward in the direction of the constellation Scorpius in the days ahead, as the crescent moon grows thicker ahead of its first quarter phase on Oct. 29, when its entire right side will be lit by direct sunlight.

Stargazers interested in getting a closer look at the wonders of the night sky should check out our roundups of the best telescopes and binoculars available in 2025, while those new to the hobby should read our roundup of the best smartphone astronomy apps for navigating the post sunset realm.

Editor's Note: If you would like to share your astrophotography with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

Look to the east slightly ahead of dawn on Sept. 2 to catch a fleeting glimpse of fleet-footed Mercury alongside the bright star Regulus, before it becomes lost in the light of the rising sun.

Stargazers hoping to catch a brief glimpse of Mercury should find a viewing spot with a clear view of the eastern horizon and be in position an hour before sunrise in order to stand a chance of spotting the elusive planet as it rises slightly before the sun.

The rocky world will appear as a bright morning star hugging the horizon among the stars of the constellation Leo, with the bright star Regulus — also known as the "heart of the lion" — located less than 2 degrees to its lower right. Remember, the width of your little finger held at arm's length is approximately 1 degree in the night sky.

Venus will be visible as a bright point of light to the upper right of Mercury on Sept. 2, with mighty Jupiter positioned beyond to form a diagonal line of solar system planets. A 6-inch telescope will allow you to resolve the cloud bands on Jupiter, along with the moon-like phases of Venus, though we would strongly advise against turning binoculars or a telescope on Mercury owing to its proximity to the rising sun.

As the closest planet to the sun, Mercury's tight orbit prevents it from ever rising particularly high in Earth's sky. On the morning of Sept. 2, Mercury will reach an altitude of just 6 degrees at sunrise from the perspective of viewers in New York, and will quickly be overwhelmed by the glow of the sun as it draws closer to the horizon.

Mercury will be nearly impossible to spot for the remainder of the month as it draws closer to the sun in the sky ahead of its superior solar conjunction on Sept. 13, when it will pass on the opposite side of the sun relative to Earth. The months that follow will see Mercury appear as a bright evening star, which will be visible low on the western horizon in the hours after sunset.

Early risers are in for a spectacular show next week, when Jupiter, Venus and Mercury form a planetary lineup in the predawn sky on Sept. 1.

Look above the eastern horizon in the hours preceding dawn on Sept. 1 to find Venus shining among the stars of the constellation Cancer, with Jupiter visible as a bright point of light roughly 20 degrees to the amber planet's upper right. It's useful to remember the width of your clenched fist held at arm's length accounts for roughly 10 degrees of sky.

Mercury, meanwhile, will rise roughly an hour before the sun to form a near-perfect diagonal line with Venus and Jupiter that traces the path of the ecliptic — the narrow plane in Earth's sky that contains the orbits of all eight solar system planets. The latecomer will swiftly become lost in the glare of the morning sun, so be sure to find a spot with a clear view of the eastern sky to ensure a view of the planetary formation.

The planetary trio will indeed present a spectacular sight to the naked eye, but a telescope with an aperture of 6-inches or more will help reveal the four large Galilean moons surrounding the gas giant Jupiter, and display the moon-like phases of Venus and Mercury.

As always, the greatest care must be taken to never point a telescope or binoculars in the direction of the rising sun — particularly when viewing Mercury, which never strays far from the horizon — as doing so will permanently damage your eyesight.

Stargazers interested in seeing the planets for themselves should read our guides detailing the best telescopes and binoculars for exploring the post-sunset sky. Photographers looking to upgrade their equipment ahead of the next big skywatching event should also check out our roundups of the best cameras and lenses for astrophotography.

Editor's Note: If you capture an image of Mercury with Venus and Jupiter and want to share it with Space.com's readers, please send your photo(s), comments, name and the location of your shoot to spacephotos@space.com.

Mercury will be farthest from the sun on Tuesday (Aug. 19), granting early risers a perfect opportunity to spot the fleet-footed world somewhat separated from the glare of our parent star.

Mercury treads such a tight orbit around the sun that it never strays far from the horizon. This makes it one of the trickiest planets to see, especially compared to Mars, Jupiter, Saturn, Uranus and Neptune, whose distant orbits beyond Earth allow them to appear high in the night sky depending on the time of year.

Astronomers call Mercury's farthest point from our the sun in the morning sky the point of "greatest western elongation," which will next occur at 8:25 a.m. EDT (12:25 GMT) on Tuesday.

Greatest elongation is the ideal time to spot Mercury during its morning appearance. Even then, it won't climb very high. For observers in New York, for example, the planet will rise a mere 16 degrees above the eastern horizon by the time the sun slips into view, making it a challenging yet rewarding target to hunt through the summer sky.

To spot Mercury, look to the east in the hour preceding dawn. The rocky world will shine low among the stars of the constellation Cancer, with Venus and Jupiter forming a line to its upper right, below a 14%-lit waning crescent moon.

The light of the rising sun will begin to swamp Mercury when it is a mere 10 degrees above the horizon, about the width of your outstretched fist, so be sure to find a location with a clear view to the east to give yourself the best chance of spotting the elusive planet.

Mercury will appear as a bright "morning star" to the unaided eye on the morning of Aug. 19. Viewing the rocky world through a telescope with an aperture of 4 inches or more under good atmospheric conditions may reveal Mercury's moon-like phases. On the morning of Aug. 19, the world will appear as a tiny 41%-lit crescent, though utmost care must be taken to never point your telescope near the rising sun, as doing so can permanently damage your vision.

Stargazers interested in seeing the phases of Mercury and other solar system worlds up close should check out our guide to the best telescopes available in 2025

Editor's Note: If you capture an image of Mercury and want to share it with Space.com's readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.

What do many baked goods and the planet Mercury have in common? They shrink as they cool.

Evidence suggests that since it formed about 4.5 billion years ago, Mercury has continuously contracted as it has lost heat. And somewhat like a fresh-baked cookie or cheesecake, Mercury also cracks as it cools: Thrust faults cut through the planet’s rocky surface to accommodate the ongoing shrinking.

By observing how faults have uplifted parts of Mercury’s surface, researchers can begin to estimate how much Mercury has contracted since it formed. However, prior estimates have varied widely, suggesting that thanks to faulting resulting from cooling, Mercury’s radius has shrunk by anywhere from about 1 to 7 kilometers.

To resolve this discrepancy, Loveless and Klimczakemployed an alternative method for estimating shrinkage caused by cooling-induced faulting on Mercury.

Prior estimates all relied on a method that incorporates the length and vertical relief of uplifted landforms, but that produces different shrinkage estimates depending on the number of faults included in the dataset. In contrast, the new method’s calculations are not reliant upon the number of faults. Rather, it measures how much the largest fault in the dataset accommodates shrinkage, then scales that effect to estimate the total shrinkage.

The researchers used the new approach to analyze three different fault datasets: one including 5,934 faults, one including 653 faults, and one including just 100 faults. They found that no matter which dataset was used, their method estimated about 2 to 3.5 kilometers of shrinkage. Combining their results with prior estimates of additional shrinkage that may have been caused by cooling-induced processes other than faulting, the researchers concluded that since Mercury’s formation, the planet’s radius may have shrunk by a total of 2.7 to 5.6 kilometers.

The new estimates could help deepen the understanding of the long-term thermal history of Mercury. Meanwhile, the authors suggest, the same methodology could be used to investigate the tectonics of other planetary bodies, like Mars, that feature faults. This paper was published in AGU Advances.

This article was originally published in Eos. Read the article here.

Mercury may be small, but it's mighty, zipping around the sun faster than any other planet.

And despite being so close to the sun, it's not the hottest planet. Venus still holds that title!

Scientists have been working hard to unlock Mercury's secrets. What's inside this dense little world? Why does it have a magnetic field? And how did it end up with such a wild orbit?

Whether you're a space enthusiast or just dipping your toes into the cosmic pool, this Mercury quiz is your chance to shine.

Try it out below and see how well you score!

Think you know your way around the solar system?

From the scorching surface of Mercury to the icy edges of Neptune, our planetary neighborhood is full of wonders. The order of the planets isn't just trivia—it tells a story about temperature, composition, and even the possibility of life. Understanding the planets' sequence helps us grasp how the solar system formed and how it functions today.

In this quiz, you'll be challenged to put the eight planets in their correct order from the Sun.

Whether you're a seasoned space explorer or just dipping your toes into astronomy, it's time to test your cosmic knowledge!

Try it out below and see how well you score!

Mercury reaches its point of greatest eastern elongation on Friday (July 4), presenting an excellent opportunity to spot the rocky planet during its evening apparition in the post-sunset sky.

Astronomers describe Mercury as an "inferior planet", because its orbital path around the sun is much closer than that of Earth. As a result, Mercury never strays far from the sun in our sky and always appears low on the horizon compared to planets like Jupiter and Mars, whose distant orbits allow them to ride high on the line of the ecliptic (the plane of the major planets' path around the sun).

The point at which Mercury appears most distant from the sun in Earth's sky, known as its point of greatest elongation, will occur at 00:37 a.m. EDT (0437 GMT) on July 4, according to stargazing website in-the-sky.org. Viewers in the U.S. will have a golden opportunity to spot Mercury shining low above the western horizon immediately after sunset over the coming days.

The rocky world will appear as a bright "evening star" approximately 15 degrees above the western horizon in the constellation Cancer at sunset for viewers in New York on July 4. For context, 10 degrees is roughly the same as the span of your clenched fist when held at arms length against the night sky.

Mercury's low altitude could make it a challenging target for those in built-up areas, so we would advise scoping out a spot with a clear horizon ahead of time if you want to catch a glimpse of the fleet-footed planet before it sets less than an hour and a half after sundown.

The "Great Bear" of the constellation Ursa Major will become visible around the time Mercury slips out of view, with the stars of Leo and the red light of Mars beating a path toward the western horizon as the night wears on.

Stargazers hoping to explore the wonders of the cosmos for themselves should check out our roundup of the best telescopes and binoculars available in 2025. If you're new to the hobby you should also check out our roundup of the top paid and free smartphone astronomy apps, many of which use augmented reality tech to help you find your way around the night sky.

Editor's Note: If you snap a picture of Mercury and want to share it with Space.com's readers, then please send it alongside your comments, name and location to spacephotos@space.com.

The new moon occurs on June 25. A day later, Mercury reaches its highest point in the evening sky, and on June 27, the young moon will make a close pass to the planet.

The exact moment of the new moon phase occurs at 6:31 a.m. Eastern Daylight Time (1031 UTC), in New York, according to the U.S. Naval Observatory. A new moon describes the moment when the sun and moon share a celestial longitude (called right ascension by astronomers), a projection of Earth's longitude lines on the sky measured eastward from the point where the sun crosses the celestial equator.

This position is also called a conjunction, and it can only happen when the moon is directly between Earth and the sun.

Sometimes the sun, moon and Earth line up perfectly, and the result is a solar eclipse. No eclipse is scheduled for this new moon, though – the next one is due on Sept. 21. Outside of solar eclipses, new moons are not visible.

Lunar phases are determined by the moon's position in its orbit around Earth, so they occur at the same time everywhere; the difference in the hour is solely due to one's time zone. The new moon thus occurs at 3:31 a.m. in Los Angeles, 11:31 a.m. in Paris, and 7:31 p.m. local time in Tokyo.

Visible planets

On June 25 the sun sets at 8:31 p.m. in New York, according to the U.S. Naval Observatory; just five days after the solstice (June 20), so in the Northern Hemisphere days are still quite long. The sky starts to get dark enough to see bright objects by about 9:15 p.m. At that point, one can see Mercury if there is a clear horizon. From New York City the planet will be about 8 degrees above the horizon; tricky to spot, but still possible if conditions are right.

On June 26, Mercury reaches its highest elevation for Northern Hemisphere observers; at 9:15 it is still about 8 degrees high; that day the moon will be a thin crescent on the right side of the planet. On June 27, in the wee hours of the morning in New York (2:03 a.m.), the moon passes within 3 degrees of Mercury; while the conjunction itself won't be visible (both the moon and Mercury are below the horizon) by the evening the moon will appear to the left of the planet and above it.

Mars, meanwhile, will be low in the west, as the planet sinks a bit each day towards the evening sun; by August, Mars will be lost in the solar glare. One can spot it easily by its reddish color; while the planet is not as bright as it can be (it is at a point in its orbit where it is further from Earth) the color remains distinct.

Saturn rises after midnight at 12:48 a.m. EDT, (June 26) followed by Venus at 2:56 a.m. By sunrise at 4:53 a.m. Saturn is at 40 degrees and Venus at about 23 degrees; a good exercise is to see how close to sunrise one can still spot the two planets.

For those located closer to the equator, Mercury is a bit higher; from Bridgetown, Barbados, it is at 22 degrees at sunset (6:28 p.m.) and won't be visible until about a half hour later. The planet sets at 8:10 p.m. June 25. The June 27 conjunction with the moon is more visible as one goes far westwards from New York; in Honolulu, Hawaii, the conjunction is at 8:03 p.m. and Mercury will still be 12 degrees above the western horizon with the thin crescent moon above it at about 22 degrees. In the tropics, the effect of seasons on day length is much less pronounced – sunset on June 25 in Honolulu is at 7:17 p.m., rather earlier than in New York.

From the Southern Hemisphere, Mars will be in the northwest after sunset. As it is the austral winter, sunsets are early. In Santiago, Chile, for example, sunset is at 5:43 p.m. local time on June 25. By 6:30 p.m. local time Mars is 40 degrees above the northwestern horizon in the constellation Leo.

Closer to the horizon is Mercury which, as in the Northern Hemisphere, is a challenge to observe, but it is slightly higher for austral sky watchers; about 10 degrees high, so with a clear horizon and no trees or buildings one can catch it. Mercury sets in Santiago by 7:33 p.m. local time.

In Santiago, Saturn rises on June 26 at 12:48 a.m. Venus rises at 4:20 a.m.; by 6 a.m. Saturn is about 53 degrees high in the north-northeast and Venus is at 20 degrees in the northeast. Sunrise isn't until 7:47 a.m., by 7 a.m. as the sky is getting light one can see Venus in the northeast and Saturn just west of north.

Constellations

In June in the Northern Hemisphere, the sky doesn't get fully dark until about 10 p.m. at the latitude of New York, Denver, San Francisco or Tokyo. In New York City, astronomical twilight, when the sun is between 12 and 18 degrees below the horizon and the last of the daylight disappears, is between 9:47 and 10:37 p.m. on June 25.

At 10 p.m., as one can look south and see the red star Antares, about 21 degrees high; one can distinguish it from Mars because the planet will be in the west (to the right). Another way to know the difference immediately is that on nights when stars visibly twinkle planets shine with a steady light. At this time of year one can see the entirety of Scorpius, the Scorpion, from mid-northern latitudes, though the very end of the Scorpion's tail is brushing the horizon and is only visible if there's nothing in the way. That said, one can easily catch the three stars to the right of Antares that mark the claws.

Turning eastwards (left) and even closer to the horizon one can see the "teapot" shape of Sagittarius the Archer rising; it gets more visible as the night progresses and gets to its highest altitude (about 20 degrees) by about 1 a.m. June 26.

Further left, almost due east at 10 p.m. and about 23 degrees high is Altair, the eye of Aquila the Eagle, which is the southernmost point of the Summer Triangle. The other two are Vega, or Alpha Lyrae, which is upwards and to the left of Altair, more than halfway to the zenith in the east-northeast. The third star is Deneb, the brightest star in Cygnus, the Swan, located a bit higher than Altair and towards the northeast. All three stars form a right triangle shape with the 90-degree corner at Deneb and are bright enough that they are visible even in light-polluted areas.

The Big Dipper, which is a common orientation point for Northern Hemisphere sky watchers, is in the northeast, about two thirds of the way to the zenith from the horizon. At 10 p.m. it will be to the left as one faces north, almost vertical with the bowl on the downward side. On the bottom side of the bowl in this orientation are the stars called Dubhe and Merak that point to Polaris. Dubhe will be on the right; one finds Polaris, the Pole Star, by making a line between the two and continuing until one reaches it. The Big Dipper is not a constellation in itself; it is part of the larger group that is the constellation Ursa Major, the Great Bear. Polaris is the end of the handle of the Little Dipper, the asterism that makes up most of Ursa Minor, the Little Bear.

Following the handle of the Dipper one can "arc to Arcturus" –a sweeping motion along the curve of the handle gets you there, to the brightest star in Boötes, the Herdsman. Continuing that arc one hits Spica, the brightest star in Virgo. If one draws a line between Dubhe and Merak away from Polaris one reaches Leo, the Lion.

Arcturus is high at 10 p.m. – 62 degrees above the southwestern horizon. Looking a bit to the left, one can see an arc of stars with a brighter one at the halfway point of the arc; this is Corona Borealis, the Northern Crown. The bright star Alpha Corona Borealis is called Alphecca; at this point one is looking almost directly overhead.

Further left (east) from Corona Borealis is a square of fainter stars that makes up the central part of Hercules. The square is sometimes called the Keystone. If one moves south (toward the horizon) one meets Ophiuchus, the Serpent Holder, a large and faint constellation above Scorpius. Ophiuchus makes a large, narrow, five-sided shape – rather like a tall A-frame house.

Starting with Antares, if one looks up and to the left of it, there is a star called Pi Ophiuchi, or Sabik, that is the bottom left corner of the main body of Ophiuchus, and to the right and above that is Zeta Ophiuchi. Look slightly to the left and upwards and one sees Kappa Ophiuchi, the right upper corner of the "box" that is Ophiuchus' body (think of it as his shoulder). Look leftward and one sees the slightly brighter star Ras Alhague, Alpha Ophiuchi, the head, and to the left and downward is the other shoulder, Beta Ophiuchi or Cebalrai (pronounced with a hard C).

In the Southern Hemisphere, the sky gets dark enough to see stars by 7:00 p.m. Observers in mid-southern latitudes can see Scorpius 40 degrees high in the east; by 11 p.m. the constellation is almost directly overhead. Looking due south and upwards – two thirds of the way to the zenith – is Crux, the Southern Cross. The cross will be upright, so the bottom star is Acrux (Alpha Crucis), while on the left is Mimosa (Beta Crucis), the top is Gacrux (Gamma Crucis) and the right point is Imai (Delta Crucis).

Draw a line between Imai and Mimosa to the left and one hits Hadar, the second brightest star in Cetaurus, the Centaur. To the left of that and slightly downward is Alpha Centauri, also called Rigil Kentaurus, our nearest stellar neighbor.

Turning right towards the southwest, one can see Canopus at about 25 degrees high; it's the brightest star in Carina, the Ship's Keel. Above Canopus is a large ring of about seven stars (nine from a darker sky location) that is Vela, the Sail.

During the final week of June and continuing into the first week of July, we'll have a fair chance at sighting Mercury, the innermost planet to the sun.

Many people have never noticed that Mercury swings rapidly back and forth relative to the sun in our sky, while moving along in an orbit scarcely more than half as far from the sun as Venus.

This fastest-moving and smallest major planet (only 1.4 times wider than the moon) orbits the sun 4.15 times a year, but from our own moving vantage point it appears to go around only 3.15 times. Each year it makes about 3.5 swings into the morning sky and as many times into the evening — excursions of highly unequal character because of its eccentric orbit and the varying angles from which we view it.

Typically, as seen from the Northern Hemisphere for after-sunset views of Mercury, its spring treks into the evening skies prove to be the best. Although it did not occur officially within the spring season, this year's first evening apparition that ran from Feb. 23 through March 15 was an excellent one, since for a few days centered around the date of its greatest elongation from the sun (March 8), Mercury set just after the end of evening twilight against a dark sky.

Another opportunity

Now, this speedy, rocky little world is again available to view in the evening sky, although on this occasion, not a "spring" apparition, but more like early summer, encompassing the timeframe from June 20 through July 11. This time, Mercury's greatest elongation from the sun will come on July 4. During this current evening apparition, Mercury's climb out of the west-northwest horizon comes at a steeper angle and yet it will attain an altitude essentially as high above the setting sun as it did in late February and early March.

What is different this time around is that it is now early summer, not late winter. So, from mid-northern latitudes, the duration of evening twilight is longer by about 30 minutes. As such, unlike in early March, we cannot hope to glimpse Mercury against a dark sky.

However, during its evening appearances, Mercury always appears brightest in the days leading up to its greatest elongation. On June 20, it shone at magnitude -0.2, brighter than the similarly-hued star Arcturus, the second brightest behind Sirius as seen from northern latitudes. By July 3 it will have faded to a still respectably bright magnitude of +0.5, which would rank it among the top ten brightest stars in the sky. So, it should not be too difficult to sight against the twilight sky, low in the west-northwest about 45 minutes to one hour after sunset.

And during this week, we'll have some help in identifying it thanks to some other celestial landmarks.

First lineup: June 24

On Tuesday evening, June 24, Mercury will form a nearly straight line with two bright stars; the Gemini Twins, Pollux and Castor. Going from right to left, the distance between Castor and Pollux measures 4.5 degrees. If you were to draw an imaginary line between these two stars and extend it another 6.5 degrees to the left, you will come to Mercury.

Or, put another way, if you make a clenched fist and hold it out at arm's length, that will measure roughly 10 degrees. The distance from Mercury to the star Castor (going from left to right) should measure a bit more than one fist width, or about 11 degrees.

In addition, keep in mind that Mercury will appear much brighter than either Pollux and Castor. On this night, Mercury will shine at zero magnitude, while Pollux will appear only about a third as bright at magnitude +1.1 and Castor only about one quarter as bright at magnitude +1.6. So, while it's likely that you'll be able to see Mercury with your naked eye, Pollux and Castor will likely be more difficult to see amidst the twilight glow. So be sure to have a pair of binoculars on hand to help you see these Twin Stars teamed up with Mercury.

Remember: if you're looking for a telescope or binoculars to observe Mercury or any other night sky event, our guides for the best binoculars deals and the best telescope deals now can help.

Second lineup: June 26

Two evenings later, on Thursday, June 26, another celestial wanderer will appear on the scene — the moon. Only a little over 1.5 days past the new moon phase, it will appear as a very narrow, wire-thin crescent, a mere 3 percent illuminated by the sun. Here again, binoculars will prove most beneficial in helping to find not only Pollux and Castor, but this exceedingly slender lunar sliver.

But what an amazing scene awaits you if you are successful in making a sighting.

On this evening, Pollux and Castor will be pointing directly at the moon and the gap separating this trio will be equidistant: From Castor to Pollux will measure 4.5 degrees and from Pollux to the moon will measure another 4.5 degrees; a celestial triple play.

But don't forget Mercury.

It will be shining about 4.3 degrees to the left and ever-so-slightly above the moon. In short, four prominent celestial objects — the moon, a bright planet and two bright stars — stretched out across a little more than a dozen degrees of the west-northwest sky.

A celestial quadruple grouping!

But please keep in mind that in many parts of the country, June has a reputation for being a sultry, hazy and humid month. So unfortunately, visibility of objects so low to the horizon might hinder seeing this "celestial summit meeting." But if your local sky is clear and transparent, try not to miss it, for gatherings like this of the moon accompanied by bright stars and planets are unusual and wonderful sights.

An August encore for early risers

Mercury will quickly move away from the Gemini Twins in the days following June 26, and will rapidly fade after July 4, transitioning into the morning sky on July 31. On balmy mornings in August, get up early to see this elusive planet climbing almost straight up above the point of sunrise.

By Aug. 19, about an hour before sunrise, it will reach its highest, with the "dynamic duo" of Venus and Jupiter, respectively 15 and 22 degrees higher still. Pollux and Castor will also be nearby and on the mornings of Aug. 20 and 21, the moon will again join in too!

Mark your calendars ...

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, Sky and Telescope and other publications.

The nights surrounding June 7 will see Jupiter and Mercury crowd together close to the horizon in the northwestern sky.

Stargazers in the U.S. will need a clear horizon to spot the planetary duo hanging less than 10 degrees (about a fist's width at arm's length) above the western horizon when the sun sets on June 6, with Jupiter positioned to the upper left of Mercury. The planets will only be visible for around 45 minutes after sunset, at which time they will follow our star below the horizon.

The following evenings will see fleet-footed Mercury draw level with Jupiter, before rising above and away from the gas giant in the night sky as a result of the smaller world's tight orbit around the sun. On June 7, the planets will pass a little over two degrees from each other - close enough to fit comfortably inside the field of view of a pair of 10x50 binoculars. Ensure that the sun has set entirely below the horizon before you point any binoculars or telescopic gear in its direction.

Side by side in the night sky, the two points of light appear similar in nature, belying the extreme differences of the solar system bodies they represent. Jupiter is a gas giant and the largest planet in our solar system, capable of fitting the smallest planet - rocky Mercury - within its expanse many thousands of times over.

Their orbits are similarly divergent. It takes Jupiter 12 Earth years to complete a single lap of our star while travelling at an average orbital distance of 484 million miles (778 million kilometers). Counterintuitively, the gas giant has the shortest day of any planet in the solar system, taking a mere 9.9 hours to spin on its axis, according to NASA.

Mercury, on the other hand, is separated on average by 29 million miles (47 million kilometers) from our star and completes a circuit of the sun every 88 Earth days  — much shorter than the 176 Earth days that it takes for the tortured world to complete a full day-night cycle.

Night sky enthusiasts hoping to explore the planets of our solar system for themselves should check out our guides to the best binocular and telescope deals. Those new to the night sky should also read our guide detailing the top smartphone stargazing apps available in 2025.

Editor's Note: If you capture a picture of Jupiter and Mercury and want to share it with Space.com's readers, then please send it along with your comments, name and the location of the shoot to spacephotos@space.com.

The predawn hours of April 28 will see a planetary triangle form in the night sky, as Venus makes a close approach to Saturn following a conjunction, while Neptune, invisible to the naked eye, will sit just a few degrees away towards the horizon.

Saturn and Venus will be below the horizon for viewers in the U.S. when they reach the point of conjunction in the hours before their appearance on the morning of the 28th. A planetary conjunction occurs when two worlds share the same right ascension  —  a value similar to longitude that is used by astronomers to chart the locations of objects in the night sky  —  when viewed from the night sky from Earth.

At this point the planetary duo will be separated by a little under 3.5 degrees in the sky, according to stargazing website in-the-sky.org (the width of your first at arm's length equals about 10 degrees).

To catch Saturn, Venus and Neptune at play, stargazers need only find a clear, unobstructed view of the horizon, and look eastward in the hour preceding sunrise on April 28.

Venus will be visible as a bright magnitude -4.42 morning star near the horizon, while Saturn will appear just a few degrees away to the bottom left, significantly dimmer than its planetary neighbor.

Neptune will be altogether invisible to the naked eye, but can be picked out with a decent pair of binoculars, or a telescope, appearing as a small blueish green point of light below and slightly to the left of Venus. However, as always the utmost care must be taken to never point a pair of binoculars or telescope at the sun, or to look directly at the stellar body with the naked eye.

Mercury will also be present close to the eastern horizon in the hour before dawn, but will be quickly hidden by light from our rising sun.

Looking to explore the solar system for yourself? well our guides for the best binoculars deals and the best telescope deals now can help. Our guides on the best cameras for astrophotography and best lenses for astrophotography can also help you prepare to capture the next skywatching sight.

Editor's note: If you want to share your planetary photographs with our readers at Space.com, please email them to spacephotos@space.com.

We now have a fine opportunity to view the planet that many astronomy guide books refer to as the most difficult of the naked-eye planets to see. The planet in question is Mercury.

Beginning now and running through the end of the second week of March, this somewhat overgrown version of the moon will have an evening appearance about as favorable as we northerners ever get to see.

In general, the most favorable elongations of Mercury — morning or evening — are those when the planet rises or sets in a dark sky, and that situation will occur for a five-day interval beginning later this week. From March 5 through March 10, Mercury will set at, or shortly after the end of evening twilight, more than 1 hour 30 minutes after sunset for mid-northern latitudes.

A bad rap

Mercury is popularly known as the "elusive" planet. Read what the New Handbook of the Heavens — considered one of the best guides to the stars for the amateur astronomer — said about Mercury:

"It stays close to the sun like a child clinging to its mother's apron strings, because you must look for it so soon after sunset or before sunrise, there was a famous astronomer, Nicolaus Copernicus, who never saw the planet in all of his life."

And yet, despite its reputation, Mercury is not really that difficult to spot; just find a reasonably unobstructed horizon. A clear, haze-free sky also helps. The remark about Copernicus is rather ironic, for he was the man who pushed hard for placing the sun and not the Earth at the center of our solar system.

Although the climate of Copernicus' homeland (Poland) tended to be rather cloudy and misty, one would have to believe that such a noteworthy figure in the field of astronomical calculation must have surely tried on those occasions when the weather was more favorable. Indeed, Mercury was far from impossible to glimpse during elongations as favorable as the upcoming one.

Venus and the moon direct you to Mercury

During the first two weeks of March, Mercury will have an advantage in that it will be positioned not very far from the most dazzling of all the planets, Venus. In fact, we strongly encourage you to use Venus as your landmark to locate Mercury. And on March 1, another celestial object will help point the way to this rocky little planet: the moon.

Currently, Mercury sets about 90 minutes after sunset; about a half hour after sundown look for it about 10 degrees above the west-southwest horizon. Your clenched fist held at arm's length measures roughly 10 degrees, so "one fist up" from the horizon should bring you to Mercury. You'll have no trouble in seeing it as a very bright "star" glowing with just a trace of a yellowish-orange tinge.

On March 1, Mercury is shining at a very bright magnitude of –1.0. In fact, among the stars and planets, Mercury will rank only behind Venus, Jupiter and Sirius (the brightest star) in terms of brightness.

But to make absolutely sure that you're looking at Mercury, brilliant Venus will be hovering about 15 degrees ("1.5 fists") above and slightly to the right of it, while floating about 10 degrees ("one fist") above and slightly to Mercury's left will be a slender, 5% illuminated, waxing crescent moon, almost mimicking the smile of a Cheshire cat against the twilight sky; a great occasion to make a positive identification of the so-called elusive planet using our nearest neighbor in space as a pointer.

After March 1, the moon will quickly move away to the east, but Mercury will continue to interact with Venus, drawing closer to it, while moving to its lower left. In the evenings that follow, Mercury will diminish — slowly at first — in brightness, but it will also be reaching its greatest elongation, 18-degrees to the east of the sun, on March 8. Shining then at a magnitude of -0.2 (just a trifle brighter than the similarly hued star Arcturus), Mercury should be readily visible, appearing low in the western sky and setting more than 1.5 hours after the sun.

Rapid fade out

Finally, on the evening of March 12, Mercury and Venus will be closest to each other, separated by 5.5 degrees, and appearing almost side-by-side — Mercury positioned to the left of Venus — as they descend down the western sky. By that time, Mercury will have faded to magnitude +0.7.

Mercury, like Venus, appears to go through phases like the moon. Right now, it resembles a gibbous phase, about 73% illuminated, which is why it currently appears very bright. By the time it arrives at its greatest elongation, it will appear less than half-illuminated (44%) and the amount of its surface illuminated by the sun will continue to decrease in the days thereafter. So, when it begins to turn back toward the sun's vicinity after March 8th, it will fade at a rather rapid pace.

In fact, on the evening of March 15, Mercury's brightness will have dropped to magnitude +1.6; as bright as the star Castor in Gemini and only 1/11 as bright as it is now. In telescopes it will appear as a narrowing crescent phase only 16% illuminated. This, in all likelihood will be your last view of it, for the combination of its rapid fading and its descent into the brighter sunset glow will finally render Mercury invisible after mid-March. With binoculars, you might try scanning to the left of Venus for a couple of more evenings after the 15th to try and extend your view of Mercury, but for all intents and purposes it will be gone by St. Patrick's Day.

A double identity

In old Roman legends, Mercury was the swift-footed messenger of the gods. The planet is well named for because it's the closest planet to the sun it's also the swiftest of the sun's family of eight planets, averaging about 30 miles per second and completing one circuit of the sun in only 88 Earth days.

Interestingly, the time it takes Mercury to rotate once on its axis is 59 days, so that all parts of its surface experiences periods of intense heat and extreme cold. Although its mean distance from the Sun is only 36 million miles (58 million km), Mercury experiences by far the greatest range of temperatures: nearly 900°F (482°C) on its day side; -300°F (-184°C) on its night side.

In the pre-Christian era, this planet actually had two names, as it was not realized it could alternately appear on one side of the sun and then the other. Mercury was called Mercury when in the evening sky, but was known as Apollo when it appeared in the morning. It is said that Pythagoras, about the fifth century B.C., pointed out that they were both one and the same.

Want to see planets like Mercury in the night sky? Our guides to the best telescopes and best binoculars are helpful tools for anyone hoping to get a closer look at the cosmos.

And if you're looking to take photos of the night sky or the planets, check out our guides on how to photograph the planets, how to shoot the night sky, and our guides to the best cameras for astrophotography and best lenses for astrophotography.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers' Almanac and other publications.

Editor's Note: If you get a good photo of Mercury, and would like to share it with Space.com's readers, send your photo(s), comments, and your name and location to spacephotos@space.com.

NASA has ordered a pause on all work by key planetary and astrophysics science committees due to recent executive orders by President Donald Trump.

In a series of memos sent from NASA headquarters late Friday (Jan. 31), the space agency directed the leaders of at least 10 planetary science assessment and analysis groups that cover a wide range of topics, from the exploration of the moon and solar system planets to "ocean worlds" like the icy moons of Saturn and Jupiter. According to SpaceNews, NASA's astrophysics assessment groups received similar memos, all of which cited a need to ensure the groups were in compliance with recent executive orders by Trump.

"As NASA continues to review and ensure compliance with presidential actions, we are requesting that you please pause all meetings and activities of Planetary Science Analysis/Assessment Groups," read one NASA memo to the Mercury Exploration Assessment Group, which was obtained by Space.com and was nearly identical to memos sent to other planetary science committees.

The memos cited six Trump executive actions, three of them aimed at ending diversity, equity and inclusion (DEI) programs in the federal government. Two others targeting so-called "gender ideology extremism," while another referred to "Unleashing American Energy" that roll back climate change-related executive orders by the Biden administration.

The pause order from NASA headquarters has already led to the cancellation of at least one planetary science meeting. The Mercury exploration group, known by the acronym MExAG was scheduled to hold its first in-person meeting this week from Feb. 4 to Feb. 6, but will no longer meet.

"We are forced, therefore, to cancel MExAG 2025," the Mercury committee's chair Carolyn Ernst, a planetary scientist with Johns Hopkins University Applied Physics Laboratory, wrote in a memo obtained by Space.com. "This turn of events is shocking and concerning, and is extra painful given the order comes four days before our first in-person meeting." Some committee members had already begun travel for the meeting, Ernst added.

The nearly three-day hybrid meeting was expected to include at up 200 scientists attending either in person of virtually, one scientist Ed Rivera-Valentin shared on the social media site Bluesky. It was expected to include a number of researchers connected to the BepiColombo Mercury mission run by the Japan Aerospace Exploration Agency and the European Space Agency. The probe just made its sixth flyby of Mercury on Jan. 8.

"The MExAG steering committee is heartbroken that our first in-person meeting was cancelled due to this," scientist Mallory Kinczyk wrote on Bluesky.

Vicky Hamilton, a planetary geologist with the Southwest Research Institute who chairs NASA's Mars Exploration Program Analysis Group, said in a memo to her committee that the group has stopped planning work for its own meeting scheduled for April.

"We will let everyone know as soon as we are able to resume work," she wrote in a memo obtained by Space.com.

NASA's assessment and analysis groups meet regularly to assess the latest discoveries and missions in their specific fields and report them back to the space agency's internal planetary science and astrophysics divisions. While they provide key insight into space science, the groups are not formal advisory committees overseen by the Federal Advisory Committee Act, according to SpaceNews. Many of the planetary science committees are overseen by the Lunar and Planetary Institute, which itself is managed by the Universities Space Research Association.

NASA's pause order to its analysis groups is one of several agency changes that have followed executive orders from the Trump administration.

The agency has begun restricting funding to programs related to diversity, equity and inequality, including to a Here to Observer program that connected students from underrepresented groups with NASA planetary science missions, according to SpaceNews.

SpaceNews also reported that the agency has removed a 2023 article about the NASA astronaut class of 1978, a team that included the agency's first Black, Asian-American and female astronauts, written by NASA's own history office. It appears to have been removed by Jan. 29, after being accessible as late as Jan. 25, SpaceNews added. You can still find the article on the Internet Archive.

Space.com has reached out to NASA headquarters for comment and will update this story if one is received.

The BepiColombo spacecraft has made its sixth and final flyby of the closest planet to the sun, Mercury, capturing some incredible images of the tiny world. The photos offer tantalizing hints about some of the mysteries BepiColombo will investigate when it moves into orbit around the planet next year.

The joint European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA) mission made its latest passage of Mercury on Wednesday (Jan. 8) at 00: 59 EDT (0259 GMT).

During the flyby, BepiColombo, which was launched on Oct. 20, 2018, came to within around 185 miles (295 kilometers) of Mercury's nightside, facing away from the sun. Around seven minutes later, the ESA/JAXA spacecraft flew over the tiny planet's north pole.

ESA Director General Josef Aschbacher wasted no time revealing images of Mercury captured by BepiColombo's monitoring cameras (M-CAMs) at the space agency's Annual Press Briefing on Thursday morning.

The six flybys of Mercury are a prelude to the spacecraft entering a polar orbit of the planet, which is when its actual mission will kick off. Orbital insertion is set to occur on Nov. 21, 2026.

"BepiColombo's main mission phase may only start two years from now, but all six of its flybys of Mercury have given us invaluable new information about the little-explored planet," BepiColombo's Project Scientist at ESA Geraint Jones said in a statement. "In the next few weeks, the BepiColombo team will work hard to unravel as many of Mercury's mysteries with the data from this flyby as we can."

Until then, the pictures of Mercury captured by BepiColumbo can tell scientists a great deal about the imaged regions of the solar system's smallest planet.

Shedding light on Mercury's dark craters and bright surface

The image below shows a view of Mercury's surface as BepiColombo crossed the "terminator line," the dividing line between the planet's night side and day side.

This view allowed scientists to get a view directly into the perpetually shadowed craters of Mercury. Featured in the image are the rims of Prokofiev, Kandinsky, Tolkien and Gordimer, as well as their shadowy depths.

Despite Mercury's proximity to the sun, the bottom of these craters are some of the coldest places in the solar system. These craters are of intense interest to scientists because there is some evidence that water ice exists within. This will be one of the key areas of investigation for BepiColombo when it enters orbit around Mercury.

Though Mercury looks well-illuminated in these images, the closest planet to the sun is actually surprisingly dark. The surface of Mercury only reflects around two-thirds of the light reflected by the moon.

This can be advantageous to scientists, though, as spotting a bright feature on Mercury's dark surface indicates a region where lighter material has recently been carried to the planet's surface.

The bright features in the image below indicate two possible mechanisms that carry material from Mercury's interior to its surface: volcanic activity and craters carved out by asteroid impacts.

Near the crest of Mercury in the image above is the Nathair Facula, created by the largest known volcanic explosion on the world. At the center of this volcanic fossil is a vent that is around 25 miles (40 km) wide. This has been the location of at least three major eruptions, leaving a volcanic deposit that is around 186 miles (300 km) in diameter.

To the left of the Nathair Facula is the Fonteyn impact crater, which was formed 300 million years ago, making it relatively young in relation to the 4.6-billion-year-old planet. The crater is ringed by bright ejecta, in reference to rocky debris thrown out by the asteroid impact.

During BepiColombo's time in Mercury's orbit, it will investigate the composition of lava and ejecta with scientists aiming to discover why material at the planet's surface darkens with age.

The below image shows Mercury's vast volcanic plains, the Borealis Planitia, which lies to the left of its north pole. This relatively smooth region was created by widespread lava eruptions around 3.7 billion years ago.

The lava poured into craters that had already been carved into the surface of Mercury, the Henri and Lismer craters. After the lava hardened, the cooling of the planet's interior caused its surface to contract, which embedded "wrinkles" in these plains. The BepiColombo images reveal that these plains extend across a wide proportion of Mercury's surface.

Prominent in the above image is the Mendelssohn crater, the outer rim of which barely extends above the lava which poured into it billions of years ago. Also with the Borealis Planitia is the Rustaveli crater. The surface of the solidified lava that fills both of these craters is scarred by smaller and more recent impact craters.

At the bottom left of the image is Mercury's Caloris basin, the tiny planet's largest impact crater which is over 930 miles (1,500 km) wide.

One of the oddest features in the new BepiColombo images is a boomerang-shaped lava flow above the Caloris basin. Seemingly connected to a deep trough, this lava is similar in color to that of the Caloris basin and the Borealis Planitia further to its north.

BepiColombo will collect data that scientists will use to determine if this lava moved into or out of the Caloris basin.

BepiColombo's fifth flyby of Mercury occurred on Dec. 1, 2024.

"This is the first time that we performed two flyby campaigns back-to-back. This flyby happens a bit more than a month after the previous one," said Frank Budnik, BepiColombo's Flight Dynamics Manager, in the statement. "Based on our preliminary assessment, everything proceeded smoothly and flawlessly."

BepiColombo just imaged Mercury in a whole new light — mid-infrared light, to be precise.

On the spacecraft's fifth flyby of Mercury earlier this month (out of a planned six flybys) BepiColombo pointed its Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS) at a swath of Mercury's northern hemisphere. Mid-infrared light is invisible to human eyes, but it carries a wealth of information about the mineral makeup and temperature of very hot rocks like those on Mercury's sun-baked surface. The Dec. 1 flyby marked the first time scientists have ever seen Mercury's surface in mid-infrared wavelengths, and the new view reveals some tantalizing hints about the planet's geology.

BepiColombo swooped past Mercury at a distance of 37,626 kilometers (about 23,400 miles) on Dec. 1. The most recent flyby isn't the spacecraft's closest encounter with Mercury; that happened on Sept. 4, when the spacecraft skimmed just 165 kilometers (103 miles) above Mercury's battered, scorched surface. When BepiColombo settles into orbit around Mercury in late 2026, it will pass within 590 kilometers (370 miles) of the planet at its closest point before swinging back out to 11,640 kilometers (7,230 miles). But to get there, the spacecraft has taken a spiraling route through the inner solar system, using the gravitational tug of Earth (once), Venus (twice), and Mercury (six times) to get itself on the right course at the right speed to end up in orbit around Mercury.

Those six Mercury flybys, the last of which will happen in January 2025, together offer researchers a chance to test out the spacecraft's instruments and gather scientific data that will help them refine their plan for the science BepiColombo will do while in orbit. One of the big questions scientists hope to answer about Mercury in the coming years is exactly what its surface is made of — and what that tells us about how the planet formed and evolved so perilously close to the sun’s heat and gravity. MERTIS is the instrument they hope will shed new (mid-infrared) light on that subject, because most of the minerals that combine to form rocks tend to radiate brightly in the mid-infrared wavelengths when they're very hot.

For the last two decades, MERTIS's science team has heated minerals, and combinations of minerals, to more than 400 degrees Celsius (752 degrees Fahrenheit) in the lab, then measured the mid-infrared radiation they emit. The result is a database of glowing fingerprints for several minerals, which the science team can compare to the MERTIS data to identify what different patches of Mercury's surface are made of, how hot they are, and how rough the terrain is.

"Because Mercury's surface is surprisingly poor in iron, we have been testing natural and synthetic minerals that lack iron," said Solmaz Adeli of the German Aerospace Center, project lead for the latest flyby, in a statement. "The materials tested include rock-forming minerals to simulate what Mercury's surface might be made of."

The latest flyby, MERTIS's first chance to shine, captured a swath of Mercury's northern hemisphere, including part of a wide volcanic plain and part of the Caloris Basin: a rocky plain inside a large impact crater, which, on every other orbit, passes directly beneath the sun while Mercury is at its closest point to our star. These images also contain a striking view of Bashō Crater, an impact crater previously photographed by the Mariner 10 (1974-1975) and Messenger (2011-2015) spacecraft.

"The moment when we first looked at the MERTIS flyby data and could immediately distinguish impact craters was breathtaking!" said Adeli. "There is so much to be discovered in this dataset – surface features that have never been observed in this way before are waiting for us."

From more than 37,600 kilometers (23,363 miles) away, MERTIS was able to image Mercury's surface with a relatively low resolution of 26 kilometers to 30 kilometers (16 miles to 19 miles) — enough to give the science team a broad overview, but not much detail about the planet's rocky geological history. Once BepiColombo finally settles into orbit, MERTIS will map the whole surface at a resolution of 500 meters (547 yards).

The BepiColombo Mercury probe flew close to our solar system's innermost planet this week, capturing another haunting image as it zoomed by.

On Sunday (Dec. 1), BepiColombo made its fifth of six flybys of Mercury. On this most recent rendezvous, the probe was 200 times farther from the planet than on its previous flyby, which saw it come within just 103 miles (165 kilometers) of Mercury's surface.

Despite the greater distance in this recent flyby, the probe was once again able to generate an eerie image of diminutive Mercury, shining alone in the darkness of space. This fifth flyby is the first during which the probe used its Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS) instrument, which measures the temperature and composition of the planet's surface and reveals what types of minerals are found on the planet's surface, which the European Space Agency (ESA) says is "one of the key Mercury mysteries that BepiColombo is designed to tackle."

BepiColombo is operated by the ESA and the Japan Aerospace Exploration Agency (JAXA). The probe launched in 2018 atop an Ariane 5 rocket on an eight-year voyage that will place it in orbit around Mercury.

The original mission plan had the spacecraft arriving in December 2025, but BepiColombo experienced thruster glitches that slowed things down; the probe is now set to be inserted into Mercury's orbit in November 2026.

Once there, the spacecraft will separate into two separate orbiters: ESA's Mercury Planetary Orbiter and JAXA's Mercury Magnetospheric Orbiter. The pair will then study the small, hot world with 16 different science instruments.

The spacecraft has been flying by Earth, Venus and Mercury since 2020, use the planets' gravity to help put it on the right course to enter Mercury's orbit.

BepiColombo made its first Earth and Venus flybys in 2020, and first swung past Mercury on Oct. 1, 2021. After one flyby in 2022 and 2023 each, the probe then made close approaches to Mercury on Sept. 4, 2024 and Dec. 1, 2024.

The probe's next Mercury flyby will occur on Jan. 8, 2025.

A 60-year-old tribute to America's first human spaceflight program is standing up to the test of time, but what about the contents of its time capsule not to be opened until 2464?

The Project Mercury Monument located at the Cape Canaveral launch pad from where NASA astronauts first flew into Earth orbit was dedicated on Nov. 10, 1964 "to the thousands of men and women of the free world who contributed to the success" of the United States' "pioneering man-in-space program." The primary feature of the installation is a 13-foot-tall (4 meters) sculpture of the symbol for the planet Mercury with the number "7" at its center representing the nation's original seven astronauts.

The symbol was made by Washington Steel of Pennsylvania using the same metal alloy as the company developed for the Atlas rockets that launched four of NASA's Mercury astronauts from Launch Complex-14 (LC-14).

"The monument is standing up surprisingly very well," said James Draper, director of the Cape Canaveral Space Force Museum, in an interview with collectSPACE.com. "The Cape Canaveral Space Force Station is one of the worst preservation environments in the world. We contend with challenges every day out here at the museum. We have intense sun; the salty ocean breeze — not only salty, but ionized; bad and intense tropical storms; exotic pests; and high humidity. All kinds of things that don't bode well for the preservation of anything."

"I'm astonished with the preservation of the Mercury monument," said Draper. "So whatever that steel is, it's some sort of miracle metal. I have inspected it fairly thoroughly and can't find any active corrosion or rust, while everything else on the Cape rots without significant attention."

Related: Project Mercury: America's 1st crewed space program

500 years

Encased in the monument's concrete base is a time capsule containing technical reports, photos, recordings and other memorabilia related to Project Mercury. The sealed metal box is not to be opened until 2464, 500 years after the monument's dedication.

"I'm a little skeptical to believe there's much integrity left to a lot of the materials that are in that time capsule," said Draper. "Now, if that box is made of that same 'miracle' steel, there is a possibility that things are fairly well protected from the exterior elements of Florida, but I will guarantee you that they are not protected from the inherent vice of the materials themselves."

"Wood, pulp, paper materials, films and photographic prints are all inherently unstable pieces that I guarantee, even if they did a nitrogen swab and sealed it so that Godzilla himself couldn't pry it open, the materials inside will eat themselves up over the course of 500 years," he said.

The items placed inside the time capsule were first sealed within "special plastic containers," according to documents from General Dynamics, the company that organized and underwrote the creation of the monument. Twenty-six still photos showing highlights from the Mercury program were "specially prepared" following the advice of the Eastman Kodak Company and the American Standards Association.

Other contents included (skip ahead now if you want to be surprised in 440 years):

• Proceedings of the Mercury-Atlas Booster Reliability Workshop conducted in San Diego, California on July 12 1963;
  
• The results of the first, second and third crewed orbital spaceflights, as well an overview of the entire Mercury project, including the fourth orbital flight;
  
• James Grimwood's "Project Mercury: A Chronology," published in 1963;
  
• Proceedings from a 1960 review of the space program held before the Committee on Science and Astronautics in the House of Representatives; a report on Project Mercury prepared by the same committee in 1961; and a 1962 report to the U.S. Congress on the status of the Mercury, Gemini and Apollo programs;
  
• A hardcover copy of "We Seven: By the Astronauts Themselves," published by Simon & Schuster in 1962;
  
• "Aeronautics: Past and Future" by J.R. Dempsey, president of General Dynamics and a collection of prophecies by "distinguished Americans of man's employment in space in 2063 A.D." as compiled for the fifth anniversary of the dedication of the General Dynamics/Astronautics facility in San Diego in 1963;
  
• One deck of General Dynamics "space cards;"
  
• "Friendship 7," an hour-long color film about John Glenn's Mercury-Atlas 6 orbital spaceflight and voice countdown excerpts from each of the Mercury missions;
  
• A 1:65th scale desktop model of a Mercury-Atlas launch vehicle.

Other examples of each of those items exist outside of the time capsule as well, with many, if not all of the photos, films and documents having been scanned and archived online. One irreplaceable artifact, though, is rumored, but not confirmed, to also be inside.

"According to a document in the UCF [University of Central Florida] archives, 'contents of the time capsule are said to include John Glenn's Marine Corps pilot wings...,' Draper told collectSPACE. "I have looked at a whole bunch of other sources trying to confirm that, and so far I have been unable to do so. So who knows? It could be in there. It could also be in hands of the family or tucked away in a museum."

Related: John Glenn: America's 1st space hero

'Si Monumentum Requiris Circumspice'

The Cape Canaveral Space Force Museum is today responsible for the care of the monument, but also has support from the station's cultural resource manager and a historian at nearby Patrick Space Force Base. While the Mercury 7 symbol remains in stable condition and there is nothing that can done about the time capsule, they are monitoring one other component of the 60-year-old installation.

"One of my concerns are the bronze plaques that accompany it. They are showing some surface-level patina damage," said Draper. "Different bronzes age in different forms and it's nothing aggressive, but we've tried working with our cultural resource manager on some surface treatments."

As the primary plaque reads, the monument stands 2,200 feet (670 m) west of LC-14. At the time of its dedication 60 years ago, the pad was in the process of being converted from supporting the Atlas rockets that launched astronauts Glenn, Scott Carpenter, Wally Schirra and Gordon Cooper to being used to launch the Atlas-Agena rockets that served as uncrewed targets for the subsequent Gemini program missions.

LC-14 was deactivated in 1967, abandoned in place in 1973 and declared a National Historic Landmark in 1984. Today, after seeing no launch activity for 58 years, the pad is being prepared for use again, this time by Stoke Space, a Washington-based company developing a reusable rocket intended to fly daily.

Unlike another historical marker that was located at the base of the LC-14 launch ramp and was recently moved into storage due to the work at the pad, there are no plans to relocate the Project Mercury Monument.

"It is in a fairly protected spot. There is no construction in the works or in the planning stages for that space that I see that could bring the monument or its time capsule into any form of peril," said Draper. "If something like that does arise, the museum is standing by to take an active role in securing it, either for a move to a safe location, to the museum, or whatever. That is a discussion for another day."

That is indeed fortunate given the other intention of the Project Mercury Monument, as noted by an inscription in Latin. Borrowed from the tomb of Sir Christopher Wren in St. Paul's Cathedral in London, "Si Monumentum Requiris Circumspice" translates in English to, "If you seek a monument, look about you."

The quote serves as a reminder that all of Cape Canaveral is a monument to the nation's achievements in space, as General Dynamics described in 1964.

Follow collectSPACE.com on Facebook and on X at @collectSPACE. Copyright 2024 collectSPACE.com. All rights reserved.

The BepiColombo spacecraft may have only made rapid flybys of Mercury, but it is already helping to unravel mysteries surrounding the closest planet to the sun.

In 2026, a European Space Agency (ESA)/Japan Aerospace Agency (JAXA) joint mission will fall into orbit around Mercury, the solar system's smallest planet. However, to do that, the spacecraft first needs to make several flybys of Mercury, Venus and Earth. Fortunately, these flybys are proving invaluable to science.

During a June 2023 flyby of Mercury, BepiColombo encountered several characteristics of the planet's magnetic field. This field forms a protective magnetic bubble around Mercury and guards the planet against charged particles in the solar wind similar to how Earth's magnetosphere shields our planet — but scientists are curious as to why this tiny inner planet's magnetic field is much weaker than ours.

Because Mercury is much closer to the sun than Earth is — Mercury is average distance of 36 million miles (58 million kilometers) away from the sun while Earth is about 93 million miles (150 million km) away — its magnetic bubble experiences a far more intense pummeling from the solar wind.

One of BepiColombo's main tasks will be to investigate this interaction and the properties of Mercury's magnetic field. The spacecraft will build a dynamic dual-picture of the space environment around Mercury by separating into different units: the ESA-controlled Mercury Planetary Orbiter (MPO) and the JAXA-led Mercury Magnetospheric Orbiter (MMO).

Related: BepiColombo probe captures stunning Mercury images in closest flyby yet

Rapid flybys of Mercury are helping scientists establish the final orbit of BepiColombo, but these passes have also granted operators tantalizing hints at the sort of science the mission will deliver when truly in place. The six planned flybys are also providing glimpses of Mercury that wouldn't be possible from orbit.

"These flybys are fast; we crossed Mercury's magnetosphere in about 30 minutes, moving from dusk to dawn and at the closest approach of just 146 miles (235 km) above the planet's surface," Lina Hadid, from the Laboratoire de Physique des Plasmas at Paris Observatory, said in a statement. "We sampled the type of particles, how hot they are, and how they move, enabling us to clearly plot the magnetic landscape during this brief period."

Surprises in the magnetic bubble of Mercury

Hadid and colleagues conducted their research with the aid of BepiColombo's Mercury Plasma Particle Experiment (MPPE) suite of instruments, which were active during the June 2023 flyby (the third of six encounters between the spacecraft and its target planet).

The team combined the data collected by MPPE with computer modeling, revealing the origins of interacting particles and features of Mercury's magnetic bubble.

"We saw expected structures like the 'shock' boundary between the free-flowing solar wind and the magnetosphere, and we also passed through the 'horns' flanking the plasma sheet, a region of hotter, denser electrically charged gas that streams out like a tail in the direction away from the sun," Hadid said. "But we also had some surprises."

Using BepiColombo's Mass Spectrum Analyzer, which has been designed especially for the complex space environment around Mercury, the team saw a turbulent boundary where the solar wind meets the planet's magnetic field. This was indicated by a region of turbulent plasma with the highest energies ever seen at Mercury.

"We also observed energetic hot ions near the equatorial plane and at low latitude trapped in the magnetosphere, and we think the only way to explain that is by a ring current, either a partial or complete ring, but this is an area that is much debated," Hadid added.

Ring currents like the one she describes are generated when charged particles are trapped by magnetic bubbles around planets. Earth's ring current is located at an altitude of tens of thousands of miles over its surface. Mercury's magnetosphere is more compressed against its surface than that of Earth, which means it is a puzzle how its magnetic bubble can trap particles a few hundred miles above the planet, as the team saw.

The team also studied the direct interaction between charged particles in the solar wind as well as plasma around Mercury and BepiColombo itself. This process is complicated by the fact that when the spacecraft is facing the sun, it is heated and cooled, and heavier charged particles called ions can't be detected because BepiColombo becomes electrically charged and repels them.

However, when BepiColombo slips into the shadow of Mercury, cool ions in a sea of plasma become detectable. This allowed BepiColombo to see ions of the elements oxygen, sodium and potassium around Mercury. The team thinks these particles originated from the surface of the tiny planet and were launched into space by meteorite strikes or solar wind bombardment. 

"It's like we're suddenly seeing the surface composition 'exploded' in 3D through the planet’s very thin atmosphere, known as its exosphere," MPPE instrument lead Dominique Delcourt, from the Laboratoire de Physique des Plasmas, said in the statement. "It's really exciting to start seeing the link between the planet's surface and the plasma environment."

"In this rare dusk-to-dawn sweep through the large-scale structure of Mercury's magnetosphere, we've tasted the promise of future discoveries," added Go Murakami, JAXA's BepiColombo project scientist, in the statement.

These findings emerge from the June 2023 flyby, meaning scientists still have data collected during last month's Mercury flyby to analyze. After this, BepiColombo will make its final two flybys of Mercury on Dec. 1 and Jan. 8, 2025, respectively.

When the BepiColombo Mercury probe made its closest approach yet to its target earlier this month, the spacecraft not only captured the first clear view of the planet's south pole but also collected valuable science data that underscores just how sharply and rapidly its local environment changes in response to the solar wind.

On Sept. 4, BepiColombo conducted its fourth successful swing past Mercury, in a flyby that reduced the European-Japanese probe's speed and altered its direction, taking it a step closer to entering orbit around the planet in 2026. A preliminary analysis of data collected by 10 of the spacecraft's 16 instruments shows that the environment around Mercury varies significantly with occasionally unexpected features, mission team members said last week at the Europlanet Science Congress in Berlin.

Although BepiColombo flew through the same regions around Mercury during each of the previous three flybys, the probe's instruments recorded varying counts of particles in the bubble-like magnetosphere carved out by the planet's magnetic field, said Hayley Williamson, a senior scientist at the Swedish Institute for Space Physics and a co-investigator on BepiColombo's SERENA instrument.

During the fourth and latest flyby on Sept. 4, which took BepiColombo just 103 miles (165 kilometers) above Mercury's surface, the probe for the first time recorded planetary ions, which are charged particles wafting in Mercury's magnetosphere after being blasted from its surface by the solar wind. Puzzlingly, those particles appeared to split into two different energy levels shortly after BepiColombo's closest approach, Williamson said. All in all, it seems that Mercury was sporting a slightly different magnetic environment during each flyby.

Related: BepiColombo probe captures stunning Mercury images in closest flyby yet

"They all look quite different," she said. "It really shows just how dynamic Mercury's space environment is."

A day before BepiColombo's latest close approach, a pocket of high-energy particles from the sun hit the spacecraft and Mercury. Those particles would have dramatically affected the planet's magnetosphere and may explain some of the unexpected features in the data, although further analysis is needed before drawing any conclusions, Williamson said.

The latest flyby "was the closest a spacecraft has ever flown by a planet, including Earth," said Ignacio Clerigo, who is BepiColombo's spacecraft operations manager at the European Space Agency (ESA) in Germany. He credited the mission's flight control and dynamics teams for successfully carrying out the complex encounter that was 21 miles (35 km) closer than originally planned. "It's really an engineering achievement." 

The unexpectedly close brush over Mercury's surface was due to the revised trajectory crafted by the mission team in an effort to overcome a glitch in the spacecraft's propulsion system. 

In April, engineers determined that the electric thrusters in the spacecraft's transfer module, which rely on electricity supplied by the module's solar panels, were not operating at full power. Anomalous electric currents flowing between the probe's transfer module and a unit that distributes power to the rest of the spacecraft left less power available for the thrusters, prompting the team to come up with a revised route requiring lower thrust levels.

"It's upsetting, but we have a simple solution," said Clerigo. The revised route means BepiColombo will enter into orbit around Mercury in November 2026, 11 months behind schedule. The delay will not affect the mission's science objectives, ESA said in a statement earlier this month.

The next milestone for the $1.8 billion spacecraft is a swing past Mercury on Dec. 1 and another on Jan. 8, 2025 — amounting to three flybys in about four months.

"We have a very intense year ahead," said Clerigo.

The BepiColombo Mercury probe made a flyby of its ultimate destination on Wednesday, capturing superb images of the planet's crater-covered crust.

The joint European-Japanese BepiColombo spacecraft, which launched in 2018, swooped in for its fourth Mercury flyby at 5:48 p.m. EDT (2148 GMT) Sept. 4, passing just 103 miles (165 kilometers) above the surface of the solar system's innermost planet.

The gravity assist maneuver is part of what will be the probe's eight-year voyage to enter orbit around Mercury, helping to reduce the spacecraft's speed to keep the trip on track. But beyond that, the maneuver also delivered some of the mission's best images so far, using BepiColombo's three monitoring cameras, or M-CAMs.

The images include two significant impact craters: Vivaldi, named after the famous Italian composer Antonio Vivaldi, and the newly named Stoddart crater, named for New Zealand artist Margaret Olrog Stoddart. 

Related: Thruster issues delay BepiColombo probe's Mercury arrival until November 2026

Both craters feature peak ring basins, created by large asteroid or comet impacts. The images help reveal more about the craters' complex history and Mercury's volcanic history. The image of Vivaldi also shows a discernible gap in the ring of peaks — this was created when more recent lava flows entered and flooded the crater.

"Mercury's peak ring basins are fascinating because many aspects of how they formed are currently still a mystery. The rings of peaks are presumed to have resulted from some kind of rebound process during the impact, but the depths from which they were uplifted are still unclear," David Rothery, professor of Planetary Geosciences at the U.K.'s Open University and a member of the M-CAM imaging team, said in a statement.

BepiColombo was scheduled to enter orbit around Mercury in December 2025. However, a propulsion system issue meant the spacecraft's thruster could no longer operate at full power. After months of assessment, ESA teams designed a revised trajectory, meaning Wednesday's flyby was closer than originally planned. BepiColombo is now planned to enter orbit in November 2026.

The flyby, while providing epic views of the results of 4.6 billion years of cosmic bombardment, also provided scientific measurements of Mercury's magnetic, plasma and particle environments, offering insights from areas that won't be accessible once BepiColombo officially enters orbit. Two final flybys are planned in December 2024 and January 2025.

"It is a world of extremes and contradictions, so I dubbed it the 'Problem Child of the Solar System' in the past," Jack Wright, ESA Research Fellow, Planetary Scientist and M-CAM imaging team coordinator, said in the statement. 

"The images and science data collected during the flybys offer a tantalizing prelude to BepiColombo's orbital phase, where it will help to solve Mercury's outstanding mysteries."

BepiColombo aims to spend at least a year, and possibly two, revealing the mysteries of Mercury with a suite of 16 instruments. These are spread across two orbiters, one each developed by ESA and the Japan Aerospace Exploration Agency (JAXA). The two will separate once in orbit around Mercury.

The joint European-Japanese BepiColombo spacecraft is set for a Mercury flyby late on Wednesday (Sept. 4), but thruster issues mean the probe faces a lengthy delay before entering orbit around the solar system's innermost planet.

BepiColombo launched in 2018 on an Ariane 5 rocket to seek out answers to mysteries surrounding Mercury. Its circuitous route to entering orbit around Mercury involves one Earth flyby, a pair of Venus flybys and six more around Mercury itself. The Sept. 4 flyby will be BepiColombo's fourth of Mercury to date. 

However, plans for the upcoming maneuver have been revised due to the spacecraft's thrusters no longer operating at full power, due to a glitch experienced in April this year. Engineers have since identified unexpected electric currents between BepiColombo's Mercury Transfer Module (MTM) solar array and the unit responsible for extracting power and distributing it to the rest of the spacecraft. 

"Following months of investigations, we have concluded that MTM's electric thrusters will remain operating below the minimum thrust required for an insertion into orbit around Mercury in December 2025," the European Space Agency's (ESA) BepiColombo mission manager, Santa Martinez, said in a Sept. 2 statement.

Related: BepiColombo: Exploring Mercury, the least visited planet of the inner solar system

Fortunately, the issue will not threaten the mission's chances of success over the long haul. ESA's Flight Dynamics team devised a workaround to counter the spacecraft's reduced thrust and still maintain the baseline scientific mission at Mercury by planning a new trajectory. The newly devised maneuver will see BepiColombo fly about 22 miles (35 kilometers) closer to the planet than originally planned, reducing the thrust requirements for the fifth flyby. The sixth flyby will then see the spacecraft embark on its new trajectory.

With this new trajectory, BepiColombo is now expected to arrive at Mercury in November 2026, the ESA statement noted. 

BepiColombo carries a suite of 16 instruments across two orbiters, one each developed by ESA and the Japan Aerospace Exploration Agency (JAXA). The two will separate and spend a year in orbit studying Mercury. This science phase could be extended to a second year.

"We get to fly our world-class science laboratory through diverse and unexplored parts of Mercury's environment that we won't have access to once in orbit, while also getting a head start on preparations to make sure we will transition into the main science mission as quickly and smoothly as possible," said Johannes Benkhoff, BepiColombo project scientist.

BepiColombo's main science camera is shielded until the ESA and JAXA orbiters separate. However,  three MTM monitoring cameras (M-CAMs) will snap images of the heavily cratered surface of Mercury during the upcoming flyby.

The solar system's tiniest planet may be hiding a big secret. Using data from NASA's MESSENGER spacecraft, scientists have determined that a 10-mile-thick diamond mantle may lie beneath the crust of Mercury, the closest planet to the sun. 

Mercury has long puzzled scientists as it possesses many qualities that aren't common to other solar system planets. These include its very dark surface, remarkably dense core, and the premature end of Mercury's volcanic era. 

Also among these puzzles are patches of graphite, a type (or "allotrope") of carbon on the surface of the innermost planet of the solar system. These patches have led scientists to suggest that in Mercury's early history, the tiny planet had a carbon-rich magma ocean. This ocean would have floated to the surface, creating graphite patches and the dark-shaded hue of Mercury's surface. 

The same process would have also led to the formation of a carbon-rich mantle beneath the surface. The team behind these findings thinks that this mantle isn't graphene, as previously suspected, but is composed of another much more precious allotrope of carbon: diamond. 

"We calculate that, given the new estimate of the pressure at the mantle-core boundary, and knowing that Mercury is a carbon-rich planet, the carbon-bearing mineral that would form at the interface between mantle and core is diamond and not graphite," team member Olivier Namur, an associate professor at KU Leuven, told Space.com. "Our study uses geophysical data collected by the NASA MESSENGER spacecraft."

MESSENGER (Mercury Surface, Space Environment, Geochemistry, and Ranging) launched in Aug. 2004 and became the first spacecraft to orbit Mercury. The mission, which ended in 2015, mapped the entire tiny world, discovering abundant water ice in shadows at the poles and gathering crucial data about Mercury's geology and magnetic field.

Related: Mercury was shrinking for at least 3 billion years — and it still might be today

Under pressure!

This new study also relates to a major surprise that came a few years ago when scientists re-evaluated the distribution of mass on Mercury, discovering the mantle of this tiny planet is thicker than previously thought.

"We directly thought that this must have a huge implication for the speciation [the distribution of an element or an allotrope amongst chemical species in a system] of carbon, diamond vs graphite, on Mercury," Namur said.

The team investigated this here on Earth by using a large-volume press to replicate the pressures and temperatures that exist within the interior of Mercury. They applied incredible amounts of pressure, over seven gigapascals, to a synthetic silicate acting as a proxy for the material found in the mantle of Mercury, achieving temperatures of up to 3,950 degrees Fahrenheit (2,177 degrees Celsius).

This allowed them to study how minerals like those that would have been found in Mercury's mantle in its early existence changed under these conditions. They also used computer modeling to assess data about Mercury's interior, which gave them clues to how the diamond mantle of Mercury could have been created.

"We believe that diamond could have been formed by two processes. First is the crystallization of the magma ocean, but this process likely contributed to forming only a very thin diamond layer at the core/mantle interface," Namur explained. "Secondly, and most importantly, the crystallization of the metal core of Mercury."

Namur said that when Mercury formed around 4.5 billion years ago, the core of the planet was fully liquid, progressively crystallizing over time. The exact nature of the solid phases forming in the inner core is not currently well known, but the team believes that these phases must have been low in carbon or "carbon-poor."

"The liquid core before crystallization contained some carbon; crystallization, therefore, leads to carbon enrichment in the residual melt," he continued. "At some point, a solubility threshold is reached, meaning the liquid cannot dissolve more carbon, and diamond forms."

Diamond is a dense mineral but not as dense as metal, meaning that during this process, it would have floated to the top of the core, stopping at the boundary of Mercury's core and its mantle. This would have resulted in the formation of an around 0.62-mile (1 km) thick diamond layer that then continued to grow over time. 

The discovery highlights the differences between the birth of the closest planet to the sun when compared with the creation of the solar system's other rocky planets, Venus, Earth, and Mars.

"Mercury formed much closer to the sun, likely from a carbon-rich cloud of dust. As a consequence, Mercury contains less oxygen and more carbon than other planets, which led to the formation of a diamond layer," Namur added. "However, Earth's core also contains carbon, and diamond formation in the Earth's core has already been suggested by various researchers."

The researcher hopes that this discovery could help reveal clues to some of the other mysteries surrounding the solar system's smallest planet, including why its volcanic phase was cut short around 3.5 billion years ago.

"A major question that I have about Mercury's evolution is why the major phase of volcanism lasted only a few hundred million years, much shorter than other rocky planets. This must mean that the planet cooled down very fast," Namur said. "This is partly related to the small size of the planet, but we are now working with physicists to try to understand if a diamond layer could have contributed to very fast heat removal, therefore terminating major volcanism very early."

Namur said that the team's next step will be to investigate the thermal effect of a diamond layer at the mantle/core boundary. This study could be supported by data from a mission that will follow in the footsteps of MESSENGER.

"We are also eagerly waiting for the first data collected by BepiColombo, hopefully in 2026, to refine our understanding of Mercury's internal structure and evolution," Namur concluded.

The team's research was published in the journal Nature Communications. 

A twice-flown SpaceX capsule has debuted on public display next to the second Mercury spacecraft to launch an American into Earth orbit and first Apollo command module to fly astronauts to the moon.

The last first-generation Dragon capsule that SpaceX built to ferry cargo to and from the International Space Station went on exhibit on Sunday (May 19), as part of a renovated gallery at the newly renamed Griffin Museum of Science and Industry in Chicago. A $125 million donation by hedge fund manager Kenneth C. Griffin — the largest contribution in the museum's history — helped to underwrite refreshing the Henry Crown Space Center, including adding the SpaceX display.

"This is the first major renovation to the Henry Crown Space Center since it opened in 1986," said Voula Saridakis, curator at the Griffin Museum of Science and Industry, in an interview with collectSPACE.com. "Before this, the gallery was current up until the space shuttle and the crewed and uncrewed missions through the 1990s."

"We have now updated all the content," Saridakis said. "It is still an exhibit about space exploration since the 1950s, but now it emphasizes space exploration from the past 20 to 30 years."

Related: SpaceX: Facts about Elon Musk's private spaceflight company

Astronaut Scott Carpenter's 1962 "Aurora 7" Mercury spacecraft and the Apollo 8 command module that flew Frank Borman, Jim Lovell and Bill Anders to the moon in 1968 remain star attractions, but so is now the SpaceX Dragon and other, more recent artifacts added to the gallery.

"When you first walk into the Henry Crown Space Center, that is where we have the Apollo and Mercury and you take in that history," Saridakis said. "Then, as you move towards the back, that is where you see the entry to the Dragon enclosure, go into it and experience the more recent missions, see what they represent and why they are important."

Dragon C113, which was donated by SpaceX and delivered to the museum two years ago, logged 64 days on its two missions to the space station. It was used for the 12th and 17th commercial resupply services (CRS) flights launched under contract for NASA in 2017 and 2019, respectively. Among its deliveries were the Cosmic-Ray Energetics and Mass (CREAM) science instrument and the STP-H6 demo, the latter built to perform the first space-based X-ray band communications.

C113 is the only second Dragon spacecraft to go on permanent public display after another of the first generation capsules at the Kennedy Space Center Visitor Complex in Florida. SpaceX also exhibits a flown Dragon inside its Hawthorne, California headquarters.

As part of the renovation, the Dragon and Apollo 8 were placed in custom-built conical glass cases that surround visitors in the capsules' journeys using lighting effects and video walls.

"We have created these new glass cases for both the Apollo and Dragon that provide 360 [degree] views. Both are backdropped by videos, media pieces that are very immersive, such that you feel like you're actually in space," Saridakis told collectSPACE. "Radial lights extend in line throughout the exhibit, and there are also lights inside the cases that work with the backdrop videos as you watch the footage from their launch, time floating through space and reentry."

Other artifacts in the Henry Crown Space Center benefit from new effects as well. "Aurora 7" has its own video wall, and an Apollo lunar module test article has been placed into a recreation of its original surroundings.

"It is a fantastic, unique artifact in that it's the only one used by all 12 astronauts [to walk on the moon] to train at the Kennedy Space Center. We reimagined that space so it looks more like the training area, rather than trying to present the lunar module like it was actually on the moon."

Visitors to the Henry Crown Space Center can also now see tools and food used by Apollo-era astronauts and a prototype garment and biofeedback belt worn by Mae Jemison, the first U.S. woman of color to fly into space and a Chicago native.

Saridakis said that she plans for even more to come.

"The Apollo and Mercury are on loan from the Smithsonian's National Air and Space Museum, but we are definitely looking to add more space artifacts to our permanent collection here at the Museum of Science and Industry," she said.

Follow collectSPACE.com on Facebook and on Twitter at @collectSPACE. Copyright 2024 collectSPACE.com. All rights reserved.

The BepiColombo spacecraft, operated by the European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA), could be feeling the heat even before it reaches its destination: Mercury. Thanks to a glitch, the spacecraft's thrusters are no longer operating at full power. The team has yet to determine how this will impact upcoming maneuvers, like a Mercury flyby set for later this year.

Destined to become just the second mission to orbit Mercury when in December 2025, BepiColombo is composed of two probes and something called the "Mercury Transfer Module" that scientists hope will answer many perplexing questions about the smallest planet in our solar system. (To be clear, BepiColombo has performed Mercury flybys before, but is yet to actually enter Mercury's orbit.)

These questions include things like how Mercury can be so blisteringly hot, yet have ice in its polar craters, why the planet has a weak magnetic field, and what the mysterious hollows seen on its surface are. 

The 48-million-mile-long (77-million-kilometer-long) journey to Mercury is far from straightforward for BepiColombo; the spacecraft will make a total of nine planetary flybys before being inserted into the relatively tiny planet's orbit. And, as ESA reports, the glitch experienced by the spacecraft on April 26 has complicated this journey further.

Related: Venus is leaking carbon and oxygen, a fleeting visit by BepiColombo reveals

BepiColombo, which launched on October 20, 2018, from ESA's launch facility in Kourou, French Guyana, atop an Ariane 5 rocket, experienced the glitch as it was preparing to execute a maneuver in space that would help prepare it for its fourth flyby of Mercury on Sept. 5, 2024.

The Mercury Transfer Module is equipped with solar arrays and an electric propulsion system used to generate thrust. As the spacecraft was about to begin its April 26 maneuver, however, operators found that the Transfer Module had failed to deliver enough electrical power to its thrusters.

As soon as the fault was identified, ESA operators set about rectifying it. By May 7, the team had restored power to the thrusters such that they reached 90% full capacity, but the power available from the Mercury Transfer Module is still below what it should be. This means BepiColombo is continuing to operate without its full thrust. 

ESA said the main priorities of the BepiColombo team currently are to keep the spacecraft's thrust stable at its current sub-optimal levels, and to work out how the spacecraft will handle upcoming maneuvers at less than full propulsion. Operators are also working to determine what caused the drop in power and assess if full power can indeed be restored.

During its journey to Mercury, BepiColombo completed one flyby of Earth on April 10, 2020, and two Venus flybys on Oct. 15, 2020, and Aug. 10, 2021. During these later flybys, the spacecraft collected important scientific data about Venus, which is the second planet from the sun and hottest world in the solar system. 

BepiColombo made its first Mercury flyby on Oct. 1, 2021, with its second and third flybys following on June 23, 2022, and June 19, 2023. As mentioned above, the fourth flyby of Mercury is set for Sept. 5 this year, with a fifth and sixth flyby of the first planet from the sun set for Dec. 2, 2024, and Jan. 9, 2025.

ESA has yet to reveal if or how the thruster glitch will affect these operations or the overall timeline of the mission, which is set to end on May 1, 2028, after BepiColumbo will have spent 10 Mercury years in orbit around the tiny planet.

Update, 9 p.m. EDT: Boeing Starliner's launch has been scrubbed due to a valve issue on the United Launch Alliance Atlas V rocket. Here is the link to our scrub story.

Boeing's Starliner capsule will join a very exclusive club today (May 6), if all goes according to plan.

A United Launch Alliance Atlas V rocket is set to launch Starliner and its two passengers, NASA astronauts Suni Williams and Butch Wilmore, from Florida's Cape Canaveral Space Force Station today at 10:34 p.m. EDT (0234 GMT on May 7). You can watch the action live at Space.com, courtesy of NASA.

The liftoff will kick off Crew Flight Test (CFT), a roughly 10-day shakeout cruise to the International Space Station (ISS) that will be Starliner's first-ever astronaut mission. Such crewed debuts to Earth orbit have happened just five times in American history, as NASA chief Bill Nelson noted during a press briefing on Friday (May 3).

"So, you think of it: The first time [NASA astronauts] have flown on a new spacecraft started with Mercury, then with Gemini, then with Apollo, then space shuttle, then Dragon and now Starliner," Nelson said. "So it is a historical day; it's a wonderful day."

Related: Boeing Starliner 1st astronaut flight: Live updates

Dragon is the capsule built by SpaceX, which, like Boeing, won a contract from NASA's Commercial Crew Program back in 2014 to carry agency astronauts to and from the ISS. 

The goal was to get at least one American crewed vehicle up and running as soon as safely possible in the wake of the space shuttle's 2011 retirement, which left NASA completely dependent on Russian Soyuz spacecraft for crewed transportation services to and from the ISS.

SpaceX launched its version of CFT, called Demo-2, in May 2020. Elon Musk's company has since completed seven operational astronaut missions to the station, and it's in the middle of its eighth, which launched in March. As that record shows, SpaceX has proven to be a reliable and prolific partner for NASA. But the agency is still excited to get a second American astronaut taxi online, given how complex and demanding human spaceflight is. 

"This will give us that additional capability, because we always look for a backup," Nelson said. 

If all goes well with CFT, Starliner could launch its first contracted, six-month crewed mission to the ISS as soon as early 2025.

CFT's launch will be historic in other ways as well. For example, it will be the first-ever astronaut liftoff for the venerable Atlas V, and the first crew-carrying mission for any member of the Atlas rocket family since May 15, 1963. On that day, an Atlas LV-3B launched Faith 7, the final mission of the Mercury program, which sent NASA astronaut Gordon Cooper into orbit for 34 hours and 20 minutes.

Nelson also noted another special aspect of tonight's liftoff: It will mark the first time since the May 1968 launch of Apollo 7 that a crewed mission leaves Earth from Cape Canaveral Space Force Station (or, in its former incarnation, Cape Canaveral Air Force Station).

Many astronaut missions have lifted off from Florida's Space Coast since then, including those flown by NASA's space shuttle and SpaceX's Dragon. But those flights all launched from NASA's Kennedy Space Center, which is next door to Cape Canaveral Space Force Station.

An abundance of gases, including carbon and oxygen, are being stripped away from Venus' atmosphere, according to flyby data from Europe's BepiColombo space probe. This data was obtained as the Mercury-bound spacecraft flew past Venus, and could shed new light on the leaky atmosphere of our planetary neighbor. Down the line, the findings could help scientists catalog the makeup of Venus' fragile magnetic environment as well.

Unlike Earth, a planet with an intrinsic magnetic field that protects its atmosphere from escaping into the depths of space, Venus does not possess its own, stable magnetic field. That is because its cooler interior cannot slosh around molten material, a swirling necessary to create and sustain a magnetic field. Rather, sunlight battering on the amber-hued orb charges up its atmospheric atoms, which then create electric currents that produce an unstable, sunlight-dependent magnetosphere.

In August 2021, BepiColombo flew through this weak, comet-shaped magnetosphere for 90 minutes to slow down and adjust its course while heading toward its ultimate target, Mercury. Scientists analyzing data from the spacecraft's fleeting visit, however, found some valuable Venusian information. Charged particles, or ions, appeared to be escaping the planet due to sunlight accelerating molecules in the atmosphere to extremely high speeds. Those speeds were high enough, in fact, that the ions even escaped the planet's gravity and flowed out into space.  

Related: Europe's BepiColombo spacecraft zooms within 150 miles of Mercury in close flyby

"These are heavy ions that are usually slow moving, so we are still trying to understand the mechanisms that are at play," Lina Hadid, a researcher at the Plasma Physics Laboratory in France who led the new analysis, said in a statement.

Venus' thick, hellish atmosphere is dominated by carbon dioxide, but also holds fewer amounts of nitrogen and other trace gases. Scientists previously knew tiny amounts of oxygen lofted in Venus' night-side and, last November, a different team of researchers detected the molecule on the planet's day-side too. The latter team further concluded that Venus' oxygen concentration drops in tandem with decreasing solar radiation.

Investigating the loss of these molecules and their escape mechanisms "is crucial to understand how the planet's atmosphere has evolved and how it has lost all its water," study co-author Dominique Delcourt, who is also a researcher at the Plasma Physics Laboratory, said in the same statement.

BepiColombo is nearing the end of its seven-year journey and is expected to reach Mercury in late 2025. Meanwhile, a fleet of robotic visitors are scheduled to visit Venus in the coming decade. Europe's Envision spacecraft aims to launch in 2031 while NASA's DAVINCI, originally slated for a 2029 launch, was delayed to 2031.

The resurrected VERITAS mission is now scheduled to launch no earlier than 2031 as well, although team members are still advocating for an earlier launch in November 2029.

This research is described in a paper published Friday (April 12) in the journal Nature Astronomy.

A gigantic, fiery eruption around 40 times wider than Earth recently exploded from the sun's hidden far side. The eruption hurled a massive cloud of plasma into space that later smashed into Mercury, scouring the planet's rocky surface and potentially triggering "X-ray auroras" on the unprotected world.

The eruption was likely triggered by a powerful solar flare, which occurred around 7 p.m. ET on March 9, Spaceweather.com reported. NASA's Solar Dynamics Observatory (SDO) spotted a large, partially obscured plasma filament exploding outward from behind the sun's northeast limb. Based on the amount of visible plasma, the eruption likely spanned around 310,000 miles (500,000 kilometers) across.

SDO data showed that the explosion, which likely left behind a massive "canyon of fire" on the sun's surface, also released a large coronal mass ejection (CME) — a fast-moving cloud of magnetized plasma and radiation — that collided with Mercury on March 10.

Related: Upcoming solar maximum may help solve the sun's gamma-ray puzzle

Mercury is often blasted with CMEs due to its proximity to our home star. The small planet has no atmosphere left as a result of this bombardment and is fully exposed to the full force of these solar storms. 

When electrons from CMEs hit Mercury's unprotected surface, they rapidly slow down. This deceleration causes the particles to release energy in the form of X-rays, which scientists can detect from Earth. The result is an aurora-like phenomenon that is visible in X-rays rather than visible light.

The gigantic eruption is the latest sign that the explosive peak of the sun's roughly 11-year solar cycle, known as solar maximum, may have already begun — much earlier than originally forecast.

During solar maximum, solar flares and other types of solar storms erupt more frequently and more powerfully as the sun's magnetic field weakens and eventually flips over. Scientists are already seeing signs of this happening.

In the last month, researchers have seen some of the biggest solar storms of the current cycle, including a monster X-class flare — the most powerful for more than six years — and a plume of plasma 15 times taller than Earth, which erupted from the sun's south pole.

One of the biggest concerns during solar maximum is that researchers can't properly monitor the far side of the sun, which can harbor giant sunspots that unleash surprise solar storms, like the one that just hit Mercury. It's possible that these sunspots could swing round to face Earth as the sun rotates, exposing our planet to flares and CMEs. For example, in January 2023, a hidden sunspot spat out an X-class flare without warning that narrowly avoided Earth.

One secret weapon NASA has up its sleeve to prevent being caught out by these unseen dark patches is the Perseverance rover, which can sometimes spy on the sun's far side from its home on Mars. But this only works when Earth and Mars are located on opposite sides of the sun. 

Originally published on LiveScience.com.

If there is one thing that has bothered me the most in more than 50 years of involvement in astronomy outreach, it is the way that most astronomy books give the impression that the planet Mercury is a very challenging, if not almost impossible object to see. It has, in fact, earned this planet the nickname as the "elusive planet." 

Here, for example, is a passage taken from the book "The ABC's of Astronomy" by Roy A. Gallant (Doubleday & Company, Inc. 1962): "Mercury is the most difficult planet to observe, has very little to offer, and is difficult to see because it is so small and so close to the sun." 

This certainly doesn't sound very inviting for someone who might want to try and see Mercury for themselves. And yet, the viewing prospects are not as grim as this passage suggests. In fact, on certain occasions, Mercury is not really so elusive at all. You simply must know when and where to look, and find a clear horizon. It is important, for instance, that Mercury be positioned as nearly directly above the sun's place as possible, a condition that is best fulfilled just after sunset in the late winter or early spring and before sunrise in autumn or early winter. 

Related: Night sky, March 2024: What you can see tonight

Mercury is called an "inferior planet" because its orbit is nearer to the sun than the Earth's. Therefore, it always appears from our vantagepoint to be in the same general direction as the sun. Thus, relatively few people have set eyes on it; there is even a rumor that Copernicus, living in northern Poland never saw it. Yet it's not really hard to see. You simply must know when and where to look, and find a clear western horizon.

A three-week window

And for those living in the Northern Hemisphere, right now we're in the midst of a fine "window of opportunity" for viewing Mercury in the evening sky. That window, which will close after March 31, will continue to provide good chances to see this so-called "elusive planet" with your own eyes. 

Currently, Mercury is visible about 45 minutes after sunset, very near to the western horizon. Yet, if your sky is clear and there are no tall obstructions to your view (like trees or buildings) you should have no trouble in seeing it as a very bright "star" shining with just a trace of a yellowish-orange tinge. At the moment, Mercury is shining at a very bright magnitude of –1.3. In fact, among the stars and planets, Mercury now ranks a very respectable fourth, behind Venus, Jupiter, and Sirius (the brightest star). 

In the evenings that follow, Mercury will diminish — slowly at first — in brightness, but it will also be arriving at its greatest elongation, 19 degrees to the east of the sun, on March 24. Shining at magnitude -0.1 (equal to the similarly hued star Arcturus in Boötes), Mercury will appear 22 degrees below and to the right of Jupiter. Your clenched fist held out at arm's length measures roughly ten degrees in width. So, Mercury will be positioned just over "two fists" to the lower right of Jupiter. Mercury will also be setting more than 90 minutes after the sun. In fact, from March 20 to 28, it will be setting after the end of evening twilight in a dark sky. 

As a result, this will be Mercury's best evening apparition of 2024. 

Mercury, like Venus, appears to go through phases like the moon. During early-March, just when Mercury started appearing very low in the western twilight sky, it was a nearly full disk, which is why it currently appears nearly as bright as Sirius. By the time it arrives at its greatest elongation, it will appear 43-percent illuminated, and the amount of its surface illuminated by the sun will continue to decrease in the days to come. So, when it begins to turn back toward the sun's vicinity after March 24, it will fade at a rather rapid pace. 

In fact, on the evening of March 31, Mercury's brightness will have dropped to magnitude +1.4; a trifle dimmer than the star Regulus in Leo and only 1/12 as bright as it is now. In telescopes it will appear as a narrowing crescent phase. This, in all likelihood will be your last view of it, for the combination of its rapid fading and its descent into the brighter sunset glow will finally render Mercury invisible by the start of April. 

More than a thousand degrees difference!

In old Roman legends, Mercury was the swift-footed messenger of the gods. The planet is well named for it is the closest planet to the sun and the swiftest of the sun's family, averaging about 30 miles per second; making its yearly journey in only 88 Earth days. 

Interestingly, the time it takes Mercury to rotate once on its axis is 59 days, so that all parts of its surface experiences periods of intense heat and extreme cold. Although its mean distance from the sun is only 36 million miles (58 million km), Mercury experiences by far the greatest range of temperatures: 790° F (420° C) on its day side; -270° F. (-170° C) on its night side.

Dual Identity

In the pre-Christian era, this planet actually had two names, as it was not realized it could alternately appear on one side of the sun and then the other. Mercury was called Mercury when in the evening sky, but was known as Apollo when it appeared in the morning. It is said that Pythagoras, about the fifth century B.C., pointed out that they were actually one and the same.

If you're hoping to catch a look at Mercury ,our guides to the best telescopes and best binoculars are a great place to start. If you're looking to snap photos of the night sky in general, check out our guide on how to photograph the planets, as well as our best cameras for astrophotography and best lenses for astrophotography.

Editor's Note: If you snap an image of Mercury and would like to share it with Space.com's readers, send your photo(s), comments, and your name and location to spacephotos@space.com.

Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for Natural History magazine, the Farmers' Almanac and other publications.  

The home of a famously sunken Mercury capsule and the spacecraft that brought the Apollo 13 crew back to Earth is getting an upgrade.

The Cosmosphere, a world-class space museum located in Hutchinson, Kansas, announced this week that it is ready to continue with the redesign and renovation of its Hall of Space, a series of galleries that together allows visitors to step back through the history of space exploration by way of an extensive artifact collection.

"We have done about a third of the museum, so starting with the V-2 Gallery, up through about 1961 and the Mercury-Atlas 1 capsule," Jim Remar, president and CEO of the Cosmosphere, said in an interview with collectSPACE.com. "We are now going back in and doing the final two thirds."

The work, which is set to get underway this month and be completed before the end of the year, encompasses some of the Cosmosphere's most popular exhibits, including the Mollett Early Spaceflight Gallery that opened in 2005 and the Apollo Gallery, with its unrivaled array of moon landing memorabilia. When done, the renovations will deliver a new sense of continuity when walking through the Hall's chronological presentations.

"What we're doing is creating a uniform look and feel," said Remar. "We're going to have similar graphic treatments, similar wayfinding audio and visuals. It will also open up a new brightness to the displays, so it will provide visitors with the same continuous story, but just do it in a more engaging way."

Related: Facts about NASA's Apollo program

Designed at different points during the Cosmosphere's own 60-year history, the galleries up to now have featured different aesthetics. The Apollo Gallery, for example, is dimly lit and sets its artifacts against dark backgrounds, evoking the blackness of space. By comparison, the Early Spaceflight Gallery, as the newest of the exhibitions to open, uses blue and red lighting to set apart the efforts of the United States and the former Soviet Union in the early years of the space race.

The hall's new look, as can already be seen in the completed V-2 Gallery and in renderings of the soon-to-be-redesigned rooms, opts for white and azure (or sky blue) backdrops set against darker blue or gray flooring. Black ceilings still provide a nod to the relationship the artifacts have with outer space.

"We are also incorporating a little more AV, as well as some interactivity into the gallery spaces," Remar said.

Visitors will soon be able to step onto a haptic plate to feel what happens when a rocket engine ignites and adjust the flow and aerodynamics around a vehicle while viewing the original model built to do just with the Mercury capsule.

"We'll also have a [new] replica command module placed up against the [Apollo-era] White Room to provide visitors with the sense of how the spacecraft and its entranceway connected and how the astronauts entered the command module for launch," Remar told collectSPACE. "So, a lot of fun and an opportunity for visitors to really be immersed in a great environment."

During the renovations, the plan is to keep as many of the Cosmosphere's iconic artifacts on public display as possible.

"It will be a rolling closure," said Remar. "Obviously when people come here, they do want to see [the Apollo 13 command module] 'Odyssey,' they do want to see [Gus Grissom's recovered Mercury capsule] 'Liberty Bell 7,' so we will try to keep those two iconic artifacts on display as long as we possibly can. There will be a period, obviously, during some of the demo and construction when we will have to take them off of exhibit, but that will be minimal."

Coinciding with the closures will be the opening of new exhibits in the public areas outside of the Cosmosphere's Justice Planetarium and Dr. Goddard's Lab interactive theater. Visitors will also still be able to enjoy films in the Carey Digital Dome Theater and take part in STEM activities in the CosmoKids area, as well as the shows in the planetarium and Dr. Goddard's Lab.

"We are also upgrading the public spaces in front of Dr. Goddard's Lab and the planetarium, we're taking care of some deferred maintenance and we're painting the exterior of the facility and the rockets," said Remar. "All told, we were able to raise about $4.7 million for the Hall of Space renovations and these projects."

In particular, funds were provided through federal appropriations spearheaded by Senator Jerry Moran, a SPRINT (State Park Revitalization and Investment in Notable Tourism) grant and most recently a significant donation from the Kansas City-based Sunderland Foundation.

Follow collectSPACE.com on Facebook and on Twitter at @collectSPACE. Copyright 2024 collectSPACE.com. All rights reserved.

The elusive planet Mercury reaches its furthest point from the sun on Friday (Jan. 12), with this separation allowing skywatchers a chance to spot the tiny planet. 

The fact that Mercury is the closest planet to the sun means that it is often washed out by the light from our star and thus not visible. When the planet reaches its largest separation from the sun during its orbit,  known as greatest elongation, it becomes more easily visible from Earth.

This greatest elongation will occur on Friday morning (Jan. 12) at around 10 a.m. EST (1500 GMT) when Mercury will be around 24 degrees away from the sun, according to EarthSky. 

At this time, Mercury, also the smallest planet in the solar system, will have a magnitude of around -0.5, with the minus prefix indicating a particularly bright object over Earth. Mercury will appear in the constellation of Sagittarius at the time of greatest elongation, according to In the Sky.

Mercury's points of greatest elongation happen during the tiny planet's 88-Earth-day orbit around the sun as it passes between our planet and our star. This happens roughly every 116 days, a cycle which astronomers call Mercury's synodic period. 

Following greatest elongation, Mercury speeds ahead of Earth, fitting for a world that shares its moniker with the equally fleet-footed messenger of the gods in Roman mythology.

Periods when Mercury is visible over Earth are referred to as "apparitions," and they generally last a few weeks, occurring in the evening or in the mornings, with these apparition times alternating between one another. 

The time of day at which the apparition of Mercury occurs depends on which side of the sun the planet is on as it approaches, reaches and then recedes from its point of greatest elongation. So, for instance, when Mercury is to the east of the sun, it rises and sets a short time after the sun and it is visible in the later afternoon/evening, its evening apparition. Conversely, when the planet is to the west of the sun, Mercury rises and sets before the star, and this is its morning apparition phase. 

Mercury climbs to between 9 and 21 degrees above the horizon at sunset during evening apparitions, and during morning apparitions, Mercury reaches between 11 and 19 degrees over the horizon at sunrise. These times depend on the time of year at which the apparitions occur. (10 degrees in the sky corresponds roughly to the width of your fist at arm's length.)

The current phase of Mercury's morning apparitions kicked off at the end of December 2023. Following the greatest elongation on Jan. 12, Mercury remains bright but will once again begin moving ahead of Earth, bringing the planet ever closer to the sunrise. The tiny planet will continue to brighten until February, at which time it slips back into the glare of the sun.

If you are hoping to catch a look at Mercury or anything else in the night sky, our guides to the best telescopes and best binoculars are a great place to start.

If you're looking to snap photos of the night sky in general, check out our guide on how to photograph the planets, as well as our best cameras for astrophotography and best lenses for astrophotography.

Editor's Note: If you snap an image of Mercury and would like to share it with Space.com's readers, send your photo(s), comments, and your name and location to spacephotos@space.com.

The new moon of January will be at 6:57 a.m. Eastern Time on January 11, according to the U.S. Naval Observatory, and a day later the planet Mercury will reach its greatest westward separation from the sun, showing itself as a "morning star." 

New moons happen when the sun and moon share the same celestial longitude, a position also called conjunction. At new phase, you can't see the moon from Earth because the illuminated side is facing away from us. 

New moons are only visible during solar eclipses; The only way to see the new moon is when it passes in front of the sun, causing a solar eclipse, which isn't happening this month (the next one is slated for April 8).

Related: New moon calendar 2024: When is the next new moon?

Visible Planets

The day after the new moon (Jan. 12), the sun rises at 7:19 a.m. Eastern Time in New York. Mercury rises at 5:40 a.m., so by 7 a.m. it will be about 12 degrees high in the southeast. The planet reaches greatest western elongation that afternoon at 2:18 p.m., according to skywatching site In-the-Sky.org. Mercury will still be hard to see, but one can use Venus, which will be about 19 degrees high, to find it. 

Venus is the single brightest star-like object in the sky, and it will be above and to the right of Mercury, which is fainter and only just visible as the sky starts to get light. One should try to spot Mercury as soon as possible after it rises, since the brightening sky will make it harder to see as sunrise approaches.

As one goes southwards the observing prospects for Mercury improve because the angle of Mercury's orbit (as viewed from Earth) with the horizon gets steeper. If one is in Miami, for example, Mercury rises at 5:29 a.m. and by sunrise, which is at 7:09 a.m., Mercury is a full 18 degrees high. The innermost planet won't be visible at that point as the sky is too bright, but by 6:30 a.m. it will be about 12 degrees above the southeastern horizon. 

The best observing prospects are near the equator. In Quito, sunrise on Jan 12 is at 6:15 a.m. and Mercury rises at 4:38 a.m. local time. By sunrise it is a full 23 degrees high in the southeast, and a half hour before sunrise at 5:45 a.m. Mercury is 15 degrees high. As one moves into the Southern Hemisphere the planet's elevation will decrease again; in Buenos Aires, the planet rises at 4:13 a.m., with sunrise at 5:53 a.m. A half hour before sunrise the planet is about 12 degrees high in the southeast; as in the Northern Hemisphere one can use Venus to find Mercury; Venus, about 22 degrees above the eastern horizon, will be above and to the left of Mercury.  

On the day of the new moon, Venus is still a bright morning star, and when the moon is not out it is the last celestial object one can see with the naked eye; it is a distinct, bright star even relatively close to sunrise. Venus rises at 4:45 a.m. on Jan. 11 in New York, with sunrise at 6:49 a.m. By sunrise the planet's altitude is 17 degrees. 

As with Mercury, the planet's appears further above the horizon as one approaches the equator and then starts to drop again as one gets into the Southern Hemisphere. In San Juan, Puerto Rico. For example, the planet rises at 4:27 a.m. local time and by sunrise (6:59 a.m.) the planet is a full 30 degrees above the eastern horizon. In Quito the planet rises earlier, at 3:46 a.m., and one would see the planet almost directly above Mercury in the east-southeast. And by sunrise at 6:17 a,m., Venus is 34 degrees above the horizon. 

The day of the new moon also is when Mars will start to emerge from the sun's glare in the predawn hours. From New York City (and locations of similar latitude) Mars rises at 6:23 a.m. local time, just 26 minutes before the Sun – count oneself lucky if you can spot it. In more southerly locations Mars rises further ahead of the sun, but not by much; in Quito, for example, the planet rises at 5:12 a.m. local time, but sunrise is at 6:18 a.m., and a half hour before sunrise the planet is only about 8 degrees high. As January progresses the planet will appear further west of the Sun, as the Sun moves eastwards against the background stars, making it more visible and part of a line of three terrestrial (or rocky) planets stretching from the horizon upwards in the predawn hours. 

In the evening sky, Jupiter and Saturn are both visible from locations at about 41 degrees North – New York, Chicago, Omaha, or Madrid (Spain) -- in the evening, and both are in the southern half of the sky. By about 6:30 p.m., when the sky is fully dark, Jupiter will be just west of due south, a bright yellow-white "star" about 61 degrees above the horizon. Saturn will be fainter, and much closer to the southwestern horizon as the planet sets at 8:22 p.m. in New York. Jupiter sets at later at 1:34 a.m. on Jan. 12. For Southern Hemisphere sky watchers the situation is similar in the mid-latitudes; in Melbourne, Australia, for example, on the evening of Jan. 11 Saturn sets at 11:05 p.m. local time, and the planet is about 17 degrees high in the west by 9:30 p.m. (sunset in Melbourne is at 8:46 p.m.) with Jupiter 36 degrees above the horizon in the north-northwest. Jupiter is in the northern half of the sky because from the Southern latitudes the sky is "reversed" (though in fact it's just that one is seeing the stars from the opposite side of the equator).

Stars and Constellations

Winter constellations are in full swing for Northern Hemisphere observers in January. By about 6 p.m. Orion, the Hunter, is completely above the Eastern horizon, and one can watch its stars appear as the sky darkens. Orion faces Taurus, which early in the evening is above the Hunter (the constellation is actually to the west and north). One can see the Hyades, a cluster of bright stars that is the "face" of the bull. 

Looking left, above Orion's head, one sees Gemini, the Twins, and the two stars Castor and Pollux. Castor is the uppermost of the two stars, as the Twins are on their "side" just after they get above the horizon. North and west of the Twins – above them in the early evening -- is Auriga, the Charioteer. Auriga contains the bright star Capella, which from the latitude of New York City and above never sets – it is one of the circumpolar stars. 

By about 9 p.m. on Jan. 21, Canis Major and Canis Minor, the "hunting dogs" of Orion, have both cleared the horizon and are in the southeast. Canis Major is below Orion (to its south) while Canis Minor is to the east (on Orion's right, the observer's left). Canis Major, the Big Dog, contains Sirius, the brightest star in the sky. Looking left and above Sirius one will see Procyon, the brightest star in the Little Dog. Procyon, Sirius and Betelgeuse in Orion form the Winter Triangle asterism that is easy to see even from light-polluted locations in cities and suburbs. 

By 11 p.m. Leo the Lion is fully above the horizon; one can spot it by looking for Sirius which by that point is almost due south, and turning to the left (eastwards) and upwards; one will see Procyon to the southeast. Continue left from Procyon and downwards slightly until one is facing nearly eastward; one should be ablw to see Regulus, or Alpha Leonis, also called Cor Leonis, the Heart of the Lion. Continue diagonally towards the horizon and one encounters Denebola, the Lion's tail. 

By this time of night Orion is fully "upright" with the Belt stars making a line from east to west angled slightly upwards; it's much easier to see the shape that forms Orion's shoulders and legs. If one looks at the three stars of the Belt, Betelgeuse is the one above and to the left, while Rigel, Orion's foot, is below and to the right. If the local city lights are not too bright one can spot a fainter star just above and to the right of Rigel; this is the start of Eridanus, the River, and the star is called Cursa or Beta Eridani, as it is the second-brightest star in the constellation. Eridanus' brightest star, Achernar, isn't visible at all from north of 33 degrees latitude. In the continental U.S. that means one must be in one of the states along the Gulf Coast, the southern half of Arizona or New Mexico, or San Diego. 

For Southern Hemisphere observers, January is when Puppis, Carina and Vela, the three constellations that make up the ship (connected to the Argo, the famous ship of Jason and the Argonauts) are prominent. As it is the austral summer the sun doesn't set until after 8 p.m.; for the sky to get fully dark one must wait until about 9:30 p.m. At that point in the northeastern sky one would see an "upside down" Orion, with the Belt stars above Betelgeuse, which from Melbourne is below and to the right. 

Rigel, meanwhile, is upwards and to the left, and this time when one follows the River from Cursa, one goes up a full 62 degrees to a point just west of north to Achernar. If one uses Betelgeuse and Sirius as "pointers," one can draw a line between them southwards (this will be to the right) and above that line is the bright Canopus, the brightest star in Carina, the Ship's Keel, about 52 degrees high and due east. Carina is one of three constellations that make up the legendary Argo, the ship Theseus the hero of Greek legend sailed. Between Canopus and Sirius is a group of seven fainter stars that forms a long shape something like a foot and an ankle; that's Puppis, the Poop Deck. Look just south (to the right) and one can see a ring-shaped group of stars that is Vela, the Sail.

Turning a bit further south – it will be to the right – one can see Crux, the Southern Cross, just between 12 and 17 degrees high in the south-southeast. From the latitude of Melbourne Crux is circumpolar – it never sets. Crux is one of the smallest of the 88 constellations in the sky; at that hour in January it is pointed towards the horizon. If one turns nearly due south one will see Rigil Kentaurus, otherwise known as Alpha Centauri. The Centaur is mostly below the horizon, but by midnight the constellation has almost completely risen. 

If you are hoping to catch a look at the planets or anything else in the night sky during new moons, our guides to the best telescopes and best binoculars are a great place to start.

And if you're looking to snap photos of any of these or the night sky in general, check out our guide on how to photograph the moon, how to photograph the planets, as well as our best cameras for astrophotography and best lenses for astrophotography.