The night sky tonight and on any clear night offers an ever-changing display of fascinating objects you can see, from stars and constellations to bright planets, often the moon, and sometimes special events like meteor showers. Observing the night sky can be done with no special equipment, although a sky map can be very useful, and a good beginner telescope or binoculars will enhance some experiences and bring some otherwise invisible objects into view. You can also use astronomy accessories to make your observing easier, and use our Satellite Tracker page powered by N2YO.com to find out when to see the International Space Station and other satellites. Below, find out what's up in the night sky tonight (Planets Visible Now, Moon Phases, Observing Highlights This Month) plus other resources (Skywatching Terms, Night Sky Observing Tips and Further Reading).
Monthly skywatching information is provided to Space.com by Chris Vaughan of Starry Night Education, the leader in space science curriculum solutions. Follow Starry Night on Twitter @StarryNightEdu.
Editor's note: If you have an amazing skywatching photo you'd like to share for a possible story or image gallery, please contact managing editor Tariq Malik at firstname.lastname@example.org.
Yearly Night Sky Guides:
Calendar of Observing Highlights
Wednesday, August 1 evening — Vesta Resumes Prograde Motion
On Wednesday, August 1, the large asteroid designated (4) Vesta will resume its regular eastward orbital motion after completing a retrograde loop that began in early May. After dark, look for the magnitude 6.2 object sitting 24 degrees above the southern horizon and just two degrees above the naked-eye star Garafsa (Theta Ophiuchi), which marks the eastern foot of Ophiuchus.
Sunday, August 2 from 20:16 to 20:54 UT — Double shadow transit on Jupiter
From time to time, the small round black shadows cast by Jupiter's four Galilean moons become visible in backyard telescopes as they cross (or transit) the planet's disk. For observers in Europe and western Africa only, on Sunday, August 2, Europa's shadow will begin to transit at 18:40 UT. At 20:15 UT, Io's shadow will join Europa's and the duo will transit for 39 minutes until Europa's shadow moves off the planet at 20:54 UT. Io's shadow will continue to transit Jupiter until 22:26 UT.
Saturday, August 4 at 2:18 p.m. EDT — Last Quarter Moon
At its last quarter phase, the moon rises around midnight and remains visible in the southern sky all morning. At this phase, the moon is illuminated on its western side, towards the pre-dawn sun. Last quarter moons are positioned ahead of the Earth in our trip around the sun. About 3½ hours later, Earth will occupy that same location in space. After this phase, the waning moon traverses the last quarter of its orbit around the earth, on the way to new moon.
Saturday, August 4 early evening — Ceres traverses the Triplet
In the western sky on the evening of Saturday, August 4, the eastward orbital motion of the dwarf planet Ceres (red line) will carry it between two of the spiral galaxies making up the Leo Triplet of galaxies. Magnitude 8.8 Ceres will be easy to see in binoculars or small telescopes (green circle), but the galaxies will require a larger aperture telescope and darker skies away from urban lighting. Observers in mid-Northern latitudes should attempt this challenge around 9:30 p.m. local time, when the sky has darkened somewhat and the grouping is still 10 degrees above the horizon. For Southern Hemisphere observers, the sky will darken earlier while the objects are higher and more easily seen.
Tuesday, August 7 after midnight — Uranus stationary
On Tuesday, August 7, Earth's faster orbit will cause Uranus to cease its eastward motion (red path) with respect to the distant stars and begin a westward retrograde loop that will last until early January, 2019. Look for the bluish-green magnitude 5.8 planet in southwestern Aries, sitting less than 5 degrees east of the naked-eye star Torcular (Omicron Piscium).
Thursday, August 9 from 22:13 to 23:32 UT — Double shadow transit on Jupiter
From time to time, the small round black shadows cast by Jupiter's four Galilean moons become visible in backyard telescopes as they cross (or transit) the planet's disk. For observers in eastern South America and western Africa only, on Thursday, August 9, Europa's shadow will begin to transit at 21:20 UT. At 22:13 UT, Io's shadow will join Europa's and the duo will transit Jupiter for 79 minutes. Europa's shadow will end its transit at 23:32 and Io's shadow will continue to transit Jupiter until 00:21 UT.
Friday, August 10 at 2 p.m. EDT — Moon at perigee
On Friday, August 10 at 2 p.m. EDT, the moon will reach its closest point to Earth for this month, a distance of 224,499 miles (358 078 km). Because perigee occurs mere hours before the moon's new phase, the combined gravitational tugs of the sun and moon pulling from the same direction in space will generate large tides on Earth over the following several days.
Saturday, August 11 at 5:58 a.m. EDT — New Moon and Partial Solar Eclipse
At its new phase, the moon is travelling between Earth and the sun. Since sunlight is only reaching the far side of the moon, and the moon is in the same region of the sky as the sun, the moon will be completely hidden from view. This new moon will feature a partial solar eclipse that will require proper eye protection to view. The Moon's shadow for this partial solar eclipse (brown circle) will contact Earth at dawn in Labrador, Canada and sweep across Greenland, Iceland, and the North Pole, then southwards across northern Europe, Siberia and eastern Asia. Greatest eclipse occurs off the coast of northeastern Siberia at 09:46:15 UT, at which time 68% of the Sun will be obscured.'
Sunday, August 12 overnight — Perseid meteors peak
The Perseid meteor shower, which runs annually between July 13 and August 26, will peak on Sunday evening, August 12. The best time for seeing Perseid meteors is after midnight, when the shower's radiant is higher in the northeastern sky. Derived from debris dropped by Comet Swift-Tuttle, it is always the most reliable shower of the year, delivering up to 100 meteors per hour at the peak. This year, the new moon phase at the peak will leave dark skies ideal for meteor watching.
Monday, August 13 evening – Jupiter passes Zubenelgenubi
During the week of Monday, August 13, Jupiter's eastward orbital motion (red line) will carry it just above the bright double star Zubenelgenubi in Libra. Look for the star just below the bright planet in the southwestern sky after dusk. The pairing can be seen in binoculars and will easily fit together in the field of view of a small backyard telescope (green circle).
Tuesday, August 14 evening – Crescent Moon above Venus
In the western sky on the evening of Tuesday, August 14, the young waxing crescent moon will take up a position 6 degrees above Venus, making a lovely wide field photo opportunity.
Wednesday, August 15 from 05:37 to 06:30 UT — Double shadow transit on Jupiter
From time to time, the small round black shadows cast by Jupiter's four Galilean moons become visible in backyard telescopes as they cross (or transit) the planet's disk. For observers in Hawaii and the west coast of North America only, on Wednesday, August 15, Ganymede's shadow will begin to transit the northern latitudes of Jupiter at 04:48 UT. At 05:37 UT, Io's shadow will appear at a more southerly latitude and the duo will transit Jupiter for 53 minutes. Ganymede's shadow will end its transit at 06:30 and Io's shadow will continue to transit Jupiter until 07:46 UT.
Thursday, August 16 afternoon and evening – Moon near Jupiter in Daylight
On the afternoon of Thursday, August 16, the planet Jupiter will rise in the northeastern sky at about 1:30 p.m. local time. At that time, the waxing crescent moon will be located 9 degrees above Jupiter. Over the course of the afternoon and early evening, the moon's orbital motion will carry it to within 7 degrees of the planet and the rotation of the sky will drop the moon to Jupiter's right. It's possible to see Jupiter in daylight with binoculars (orange circle) by using the moon as a reference. After dusk, the pair of objects will sink into the west and set at 11:30 p.m. local time.
Thursday, August 16 from 8:05 to 10:10 p.m. EDT — Double shadow transit on Jupiter
From time to time, the small round black shadows cast by Jupiter's four Galilean moons become visible in backyard telescopes as they cross (or transit) the planet's disk. On Thursday, August 16, Europa's shadow will begin to transit at 7:56 p.m. EDT (in evening twilight). At 8:05 p.m. EDT, Io's shadow will join Europa's and the duo will transit Jupiter until they both move off the planet at 10:10 p.m.
Friday, August 17 evening — Venus at Greatest Eastern Elongation
On Thursday, August 12, Venus will officially reach its widest separation east of the Sun. Viewed in a telescope (inset), the planet will exhibit a half-illuminated phase and will set shortly before 10 p.m. local time. After today, our sister planet will continue to brighten and swell in diameter as it swings back toward the sun and inferior conjunction in late October.
Saturday, August 18 at 3:49 a.m. EDT — First Quarter Moon
After the moon has completed the first quarter of its orbit around Earth, the relative positions of the Earth, sun, and moon cause us to see it half-illuminated — on its eastern side. A first quarter moon always rises around noon and sets around midnight, so it is also visible in the afternoon daytime sky. The evenings around first quarter are the best times to see the lunar terrain when it is dramatically lit by low-angled sunlight.
Saturday, August 18 at 9:32 p.m. EDT — Algol at Minimum Brightness
The "Demon Star" Algol in Perseus is among the most accessible variable stars for beginner skywatchers. Its naked-eye brightness dims noticeably for about 10 hours once every 2 days, 20 hours, and 49 minutes because a dim companion star orbiting nearly edge-on to Earth crosses in front of the much brighter main star. On Saturday, August 18 at 9:32 p.m. EDT, Algol will reach its minimum brightness of magnitude 3.4 and will sit just above the northeastern horizon. By 2:30 a.m. EDT, it will be halfway up the eastern sky and will have brightened to its usual magnitude of 2.1.
Monday, August 20 evening — Moon meets Saturn
In the southern sky after dusk on the evening of Monday, August 20, the waxing gibbous moon will sit 4 degrees to the upper right of bright, yellowish Saturn. The two objects will cross the sky together during the night and will easily fit within the field of binoculars (orange circle). Before they set in the west at about 2 a.m. local time, the moon's separation from the ringed planet will have noticeably decreased due to the moon's eastwards orbital motion (green line).
Thursday, August 23 from 9 to 11 p.m. CDT — Double shadow transit on Jupiter
From time to time, the little round shadows cast by Jupiter's four Galilean moons become visible in backyard telescopes as they cross (or transit) the planet's disk. On Thursday, August 23, Io's shadow will begin to transit at 9 p.m. CDT (in evening twilight). At 9:35 p.m. CDT, Europa's shadow will also begin to cross, but closer to Jupiter's northern pole. The duo will transit Jupiter until they both move off the planet as Jupiter is setting at about 11 p.m. CDT.
Sunday, August 26 at 7:56 a.m. EDT — Full Corn Moon
The August full moon, known as the "Corn Moon", "Sturgeon Moon", "Red Moon", "Green Corn Moon", and "Grain Moon", always shines in or near the stars of Aquarius or Capricornus. Full moons always rise around sunset and set around sunrise.
Sunday, August 26 pre-dawn — Mercury at Greatest Western Elongation
On Sunday, August 26, Mercury (orbit shown as a red curve) will reach an angle of 18 degrees west of the Sun, its widest separation for this apparition. Due to the steeply dipping morning ecliptic (green line), this will be an excellent pre-dawn apparition for Northern Hemisphere skywatchers, but a poor one for those in the Southern Hemisphere.
Tuesday, August 28 evening — Mars stationary
On Tuesday, August 28, Mars will cease its westward motion retrograde with respect to the distant stars (red path) and resume regular eastward motion. Mars will appear as a bright reddish star-like object sitting low in the southern sky.
Thursday, August 30 evening — Saturn among the Jewels of the Milky Way
Towards the end of August, Saturn will move to within 2 degrees of several spectacular deep sky objects, including the open star cluster designated Messier 21, the Trifid Nebula (Messier 20), and the Lagoon Nebula (Messier 8). All of these objects will fit within the same field of view of binoculars (orange circle) under very dark skies. The Messier objects 22, 23, 24, and 28 will also be within a binoculars' field diameter of Saturn.
Thursday, August 30 from 7:14 to 8:04 p.m. HST — Double shadow transit on Jupiter
From time to time, the little round shadows cast by Jupiter's four Galilean moons become visible in backyard telescopes as they cross (or transit) the planet's disk. For observers in Hawaii and environs only, on Thursday, August 30 at 7:14 p.m. HST (in evening twilight), Europa's shadow will join an Io shadow transit that commenced in daylight. The duo will transit Jupiter for 52 minutes. Io's shadow will end its transit at 8:04 p.m. HST and Europa's shadow will continue to transit Jupiter until 9:22 p.m. HST.
Friday, August 31 after sunset — Venus Kisses Spica
Low in the west-southwestern sky after sunset on the evening of Friday, August 31, the bright planet Venus will land only 1.25 degrees below the bright naked-eye star Spica in Virgo. The pair of objects will be visible in binoculars and will fit together in the field of a small telescope at low magnification (orange circle).
Mercury, which reaches inferior conjunction with the sun on August 9, will remain hidden from view for most of August. After mid-month, the planet will enter the eastern pre-dawn sky and will begin an apparition that peaks at greatest western elongation (18 degrees from the sun) on August 26. On that date, the optimal time for seeing Mercury will be at about 5:30 a.m. local time. Due to the steep morning ecliptic and Mercury moving through its ascending node on August 28, this will be an excellent morning apparition for observers in the Northern Hemisphere, and a poor one for Southerner Hemisphere observers. The planet will decrease in visual brightness during this apparition. Viewed in a telescope, Mercury's apparent disk size will shrink and wax to a gibbous phase at month-end.
During August, Venus will start to wrap up a long apparition in the western evening sky. The extremely bright planet will swing wider of the sun until August 17, when it will reach its greatest eastern elongation 46 degrees from the sun, and then it will begin to swing sunward again. The planet will spend the entire month among the stars of Virgo, and finish August only 1.25 degrees below that constellation's brightest star Spica. Meanwhile the combination of a lower evening ecliptic and Venus' orbital motion, will bring the planet lower in our sky, shortening our observing time. Venus will continue to brighten during August, starting the month at magnitude -4.31 and reaching magnitude -4.61 at month-end. At the same time, the planet's apparent disk size will increase as it moves toward Earth, and its illuminated phase will decrease from 57% to 40%. In the western sky on the evening of Tuesday, August 14, the young waxing crescent moon will take up a position 6 degrees above Venus, making a lovely wide field photo opportunity.
Mars, after reaching opposition and closest approach to Earth at the end of July, will spend August moving through the stars of western Capricornus. In early august, Mars will be a bright reddish naked-eye object visible all night long. At month-end it will peak in the south during late evening and set at 3 a.m. For mid-northern latitude observers, Mars will reach a maximum elevation of only 20 degrees above the southern horizon. Observers farther south will see Mars higher in the sky and through less of Earth's distorting atmosphere. On August 28, the Red Planet will complete a retrograde loop and resume regular eastward motion through the distant stars. As Earth slowly increases our distance from Mars, the planet will decrease in brightness; from magnitude -2.75 on August 1st to magnitude 2.1 on August 31st. At the same time, Mars' apparent disk diameter will decrease from 24.3 arc-seconds to 20.9.
Very bright Jupiter will remain easily observable during August in the western evening sky, moving eastward through the stars of western Libra. In early August it will set at around midnight. By month end, it will set 90 minutes earlier. The planet will pass 0.5 degrees above the bright double star Zubenelgenubi (Alpha Librae) around mid-month, and the pair of objects will appear together in the field of view of a telescope at low magnification. From time to time during August, the little round shadows cast by Jupiter's four Galilean moons will be visible as they cross the planet's disk, frequently two at a time. On the evenings of August 16 and 17, the waxing crescent moon will be positioned 7 degrees northwest and northeast of Jupiter respectively.
Saturn will be visible during August as a medium-bright (visual magnitude 0.2), yellowish object in the southern evening sky and slowly moving retrograde westward through the stars of northern Sagittarius - just to the east of the Milky Way. Saturn will reach its highest elevation above the southern horizon in the latter part of the evening. Because the ringed planet reached opposition just days after the June 21 solstice, it will remain relatively low in the southern sky for observers in mid-Northern latitudes this summer. The rings, which subtend an angular size of about 42 arc-seconds, continue to be well open because the planet's northern pole is tilted roughly sunward. On the evening of August 20, the waxing gibbous moon will sit less than 4 degrees to the right of Saturn and the pair of objects will easily fit within the field of binoculars. At the end of August, the Ringed Planet will move within 2 degrees of several spectacular deep sky objects, Messier objects 8, 20, and 21.
Blue-green Uranus (magnitude 5.8) will spend August among the stars of western Aries, sitting less than 5 degrees east of the naked-eye star Omicron Piscium. On August 7, Uranus' slow eastward motion will stop, and then the planet will commence a slow western retrograde loop that will last until early January, 2019. In early August, Uranus will be observable in the eastern sky after midnight. By month end it will be rising before 10 p.m. local time. The last quarter moon will pass 6 degrees below Uranus on August 4, and then take up a similar position again on August 31.
Blue-tinted Neptune (magnitude 7.8) will spend August moving retrograde westward through the stars of eastern Aquarius — shifting slowly toward that constellation's naked-eye star, Hydor. As an aid in locating the planet, look about 4 degrees to the east of Hydor and 3 degrees north of fainter Psi (ψ) Aquarii. Since Neptune will reach opposition in early September, it will be an all-night target for telescopic viewing throughout August.
Gibbous: Used to describe a planet or moon that is more than 50 percent illuminated.
Asterism: A noteworthy or striking pattern of stars within a larger constellation.
Degrees (measuring the sky): The sky is 360 degrees all the way around, which means roughly 180 degrees from horizon to horizon. It's easy to measure distances between objects: Your fist on an outstretched arm covers about 10 degrees of sky, while a finger covers about one degree.
Visual Magnitude: This is the astronomer's scale for measuring the brightness of objects in the sky. The dimmest object visible in the night sky under perfectly dark conditions is about magnitude 6.5. Brighter stars are magnitude 2 or 1. The brightest objects get negative numbers. Venus can be as bright as magnitude minus 4.9. The full moon is minus 12.7 and the sun is minus 26.8.
Terminator: The boundary on the moon between sunlight and shadow.
Zenith: The point in the sky directly overhead.
Night Sky Observing Tips
- Adjust to the dark: If you wish to observe faint objects, such as meteors or dim stars, give your eyes at least 15 minutes to adjust to the darkness.
- Light Pollution: Even from a big city, one can see the moon, a handful of bright stars and sometimes the brightest planets. But to fully enjoy the heavens — especially a meteor shower, the constellations, or to see the amazing swath across the sky that represents our view toward the center of the Milky Way Galaxy — rural areas are best for night sky viewing. If you're stuck in a city or suburban area, a building can be used to block ambient light (or moonlight) to help reveal fainter objects. If you're in the suburbs, simply turning off outdoor lights can help.
- Prepare for skywatching: If you plan to be out for more than a few minutes, and it's not a warm summer evening, dress warmer than you think necessary. An hour of observing a winter meteor shower can chill you to the bone. A blanket or lounge chair will prove much more comfortable than standing or sitting in a chair and craning your neck to see overhead.
- Daytime skywatching: When Venus is visible (that is, not in front of or behind the sun) it can often be spotted during the day. But you'll need to know where to look. A sky map is helpful. When the sun has large sunspots, they can be seen without a telescope. However, it's unsafe to look at the sun without protective eyewear. See our video on how to safely observe the sun, or our safe sunwatching infographic.