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Night sky, December 2021: What you can see this month [maps]

A clear night sky offers an ever-changing display of fascinating objects to see — stars, constellations, and 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. Binoculars or one of the best telescopes will enhance some experiences and bring some otherwise invisible objects into view. You can also use stargazing apps and software to make your observing easier, and use our Satellite Tracker page powered by 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).

You can also capture the night sky by using any of the best cameras for astrophotography, along with a selection of the best lenses for astrophotography.

The night sky is more than just the moon and stars, if you know when and where to look. (Image credit: Karl Tate/

Monthly skywatching information is provided to by Chris Vaughan of Starry Night Education, the leader in space science curriculum solutions. Follow Starry Night on Twitter @StarryNightEdu and Chris at @Astrogeoguy.

Editor's note: If you have an amazing skywatching photo you'd like to share for a possible story or image gallery, you can send images and comments in to

Night Sky Guides:

Calendar of Observing Highlights

Wednesday, December 1 - Neptune Stands Still (evening)

(Image credit: Starry Night)

On Wednesday, December 1, the distant, blue planet Neptune will complete a retrograde loop that has been carrying it slowly westward through the stars of northeastern Aquarius since late June. After pausing tonight, Neptune will return to its regular eastward motion. From dark sky locations the magnitude 7.9 planet can be observed in good binoculars and backyard telescopes for several hours after dusk. Search for the planet several finger widths to the upper left (or 3 degrees to the celestial east-northeast) of the medium-bright star Phi Aquarii (inset). The trio of stars named Psi Aquarii will sit below them. The planet and those stars will appear together within the field of view of binoculars (green circle).

Thursday, December 2 - Old Moon and Mars (pre-dawn)

(Image credit: Starry Night)

In the southeastern sky before dawn on Thursday, December 2, the slim crescent of the old moon will shine a palm's width to the upper right (or 7 degrees to the celestial northwest) of magnitude 1.6 Mars. Use binoculars (green circle) to look for the bright double star Zubenelgenubi (or Alpha1,2 Librae) positioned just to the moon's lower right. Half a day later, observers in most of Mongolia, northeastern China, parts of eastern Russia, Japan, most of Micronesia, northern Polynesia, and Hawaii can see the moon occult Mars. On Friday morning, the moon will drop to Mars' lower left. 

Friday, December 3 - Venus at Maximum Brightness (evening)

(Image credit: Starry Night)

On Friday, December 3, the evening planet Venus will achieve maximum brightness for its current lengthy evening apparition. Astronomers call this event "greatest illuminated extent". The term refers to the optimum combination of the planet's apparent disk size (41 arc-seconds) and its illuminated phase (26%) sending a maximum amount of reflected sunlight towards Earth. That evening, Venus will shine at a spectacular magnitude –4.66. Venus' crescent phase (inset) will be apparent in any telescope or spotting scope, good binoculars, or even to very sharp, unaided eyes - but ensure that the sun has fully set before using optical aids.

Friday, December 3 - Comet Leonard Passes Messier 3 (post-midnight)

(Image credit: Starry Night)

A comet discovered on January 3, 2021 by G.J. Leonard is predicted to grow to naked-eye brightness during December, and then pass the sun at perihelion on January 3. In the first few days of December, Comet C/2021 A1 (Leonard) will rise around midnight. Each night it will travel rapidly eastward near the bright star Arcturus (red path). Although the comet will brighten day by day, it will also be drawing closer to the dawn sun — so make an effort to see it sooner than later. During the wee hours of Friday, December 3, Comet Leonard will pass very close to the bright globular star cluster Messier 3 in Canes Venatici. Both objects should be bright enough to see in binoculars from dark sky locations, and will be telescope-close (green circle) for several hours. On the following night, the comet will pass another, fainter globular cluster named the Snowglobe or NGC 5466. 

Saturday, December 4 - New Moon and Antarctic Total Solar Eclipse (at 07:43 GMT)

(Image credit: Starry Night)

On Saturday, December 4 at 2:43 a.m. EST or 07:43 GMT, the December new moon will occur. At its new phase, the moon is travelling between Earth and the sun. Since sunlight can only reach the far side of the moon, and the moon is in the same region of the sky as the sun, the moon becomes completely hidden from view for about a day. This new moon will also produce a total solar eclipse visible inside a narrow track that crosses West Antarctica and the Ross Sea. The partial eclipse will be visible over the rest of Antarctica, South Africa, Tasmania, and the South Atlantic. This new moon will occur only two hours before the moon reaches perigee, producing high tides around the world. 

Monday, December 6 - Crescent Moon Passes Venus (after sunset)

(Image credit: Starry Night)

Look in the lower part of the southwestern sky after sunset on Monday, December 6 to see the slim crescent of the young moon shining a few finger widths below (or 3 degrees to the celestial south of) the very bright planet Venus, close enough to share the view in binoculars (green circle). Viewed in a telescope that night, Venus will display a 24%-illuminated crescent phase — similar to, but somewhat thicker than the moon's. Ensure that the sun has fully set before aiming optical aids low in the western sky.

Tuesday, December 7 - Moon Meets Saturn (early evening)

(Image credit: Starry Night)

The moon's monthly visit with the bright gas giant planets Saturn and Jupiter will kick off after dusk in the southern sky on Tuesday, December 7. Before the sky has fully darkened, try using binoculars (green circle) to find the yellowish dot of Saturn positioned a palm's width to the upper left (or 6 degrees to the celestial northeast) of the waxing crescent moon. Or wait until Saturn is visible with your unaided eyes. Much brighter and whiter Jupiter will be shining off to their upper left. Even brighter Venus will gleam to their lower right.

Wednesday, December 8 - Moon Hops Past Jupiter (evening)

(Image credit: Starry Night)

In the southwestern sky for several hours after sunset on Wednesday, December 8, the crescent moon will shine below and between the bright, white dot of Jupiter and somewhat fainter and creamy-colored Saturn. Very bright Venus will blaze to their lower right (celestial west) until it sets at about 7 p.m. local time. On Thursday night, the moon will hop east to sit a generous palm's width to the left of Jupiter. The moon will then bid adieu to those bright planets until January 4-5.

Thursday, December 9 - Comet Leonard in the East (pre-dawn)

(Image credit: Starry Night)

If current predictions hold, the mornings around Thursday, December 9 will offer fine opportunities to see Comet C/2021 A1 (Leonard) while it is higher and shining in a dark, moonless sky. Although the comet won't reach peak brightness for several more days, its location one-third of the way up the eastern sky, near the circle of stars that form the head of Serpens Caput (the Snake's Head), should provide good views of it in binoculars (green circle) — and possibly with your unaided eyes. On December 9, the comet will rise at about 3:30 a.m. local time — but make your viewing attempt before 5:30 a.m., when the dawn sky will begin to brighten. Comets are notoriously unpredictable — but skywatchers are looking forward to a great show from this one.

Friday, December 10 - Half-moon near Neptune and Pallas (evening)

(Image credit: Starry Night)

In the southwestern sky on the evening of Friday, December 10, the waxing, half-illuminated moon will be positioned near the faint planet Neptune and the main belt asteroid designated (2) Pallas. The magnitude 7.9 planet will be located a palm's width above (or 5.5 degrees to the celestial north of) the moon, and the fainter, magnitude 9.9 planet will be a similar distance to the moon's lower right (celestial west). The nearby bright moon will make them harder to see, so find the tight trio of stars named Psi Aquarii above the moon and use them as a guide to Neptune and Pallas on a subsequent night when the moon has moved away. On Friday evening, observers in India and much of China can see the moon occult the asteroid. 

Friday, December 10 - Two Shadows and the GRS Cross Jupiter (evening) 

(Image credit: Starry Night)

On Friday evening, December 10 in the Americas, observers with telescopes can watch the small round shadows of two of Jupiter's moon cross the planet - one of them accompanied by the Great Red Spot! At 5 p.m. EST (or 22:00 GMT), the shadow of Callisto will be completing a crossing of the planet that began at 18:15 GMT. A few minutes later, the Great Red Spot and the shadow of Europa will rotate into view on the opposite side of Jupiter's disk. The shadow and the spot will complete their own crossing several hours later, at about 8 p.m. EST (or 01:00 GMT on December 11). 

Saturday, December 11 - First Quarter Moon (at 01:35 GMT)

(Image credit: Starry Night)

The moon will complete the first quarter of its monthly journey around Earth at 01:35 GMT on Saturday, December 11. That translates to 8:35 p.m. EST on Friday, December 10. At first quarter its 90 degree angle from the sun will cause us to see the moon exactly half-illuminated - on its eastern side. At first quarter, the moon always rises around mid-day and sets around midnight, so it is also visible in the afternoon daytime sky. The evenings around first quarter are the best ones for viewing the lunar terrain while it is dramatically lit by low-angled sunlight, especially along the terminator, the pole-to-pole boundary separating its lit and dark hemispheres.

Sunday, December 12 - The Lunar Straight Wall (evening)

(Image credit: Starry Night)

On Sunday evening, December 12, the pole-to-pole terminator that divides the lit and dark hemispheres of the waxing gibbous moon, will fall just to the left (or lunar west) of Rupes Recta, also known as the Lunar Straight Wall. The rupes, Latin for "cliff", is a north-south aligned fault scarp that extends for 65 miles (110 km) across the southeastern part of Mare Nubium, which sits in the lower third of the moon's Earth-facing hemisphere. The wall, which is very easy to see in good binoculars and backyard telescopes, is most prominent a day or two after first quarter, and also the days before last quarter. For reference, the very bright crater Tycho is located due south of the Straight Wall.

Tuesday, December 14 - Geminids Meteor Shower Peak (all night)

(Image credit: Starry Night)

The Geminids meteor shower, usually one of the most spectacular showers of the year, runs from November 19 to December 24 annually. The number of meteors will gradually ramp up to a peak during the wee hours of Tuesday, December 14, and then decline rapidly on the following nights. Geminids meteors are often bright, intensely colored, and slower moving than average because they are produced by sand-sized grains dropped by an asteroid designated 3200 Phaethon. You can watch for Geminids once the sky darkens on Monday evening, until dawn on Tuesday morning. At about 2 a.m. local time, up to 120 meteors per hour are possible under dark sky conditions. At that time the sky overhead will be pointed toward the densest part of the debris field. True Geminids will appear to radiate from a position above the bright stars Castor and Pollux, but the meteors can appear anywhere in the sky. Until after it sets, at around 3 a.m. local time, a bright waxing gibbous moon on the peak night will spoil this year's shower. 

Wednesday, December 15 - Bright Moon near Uranus (all night)

(Image credit: Starry Night)

In the eastern sky after dusk on Wednesday night, December 15, the very bright, nearly-full moon will shine almost a fist's width to the lower left (or 8 degrees to the celestial east) of the magnitude 5.7 planet Uranus. By dawn on Thursday morning, the moon's orbital motion will carry it farther from Uranus in the western sky, and the diurnal rotation of the sky will move it to the upper left of the planet. While Uranus' blue-green dot can normally be seen in binoculars (green circle), I recommend noting its location between the brighter stars of Aries and Cetus, and the nearby stars Mu and Xi Ceti, and seeking it out a few nights later, when the bright moon will have moved away.

Thursday, December 16 - Gibbous Moon in Taurus (all night)

(Image credit: Starry Night)

As darkness falls on Thursday, December 16, look in the eastern sky for the bright gibbous moon shining among the stars of Taurus. The bright open star cluster known as the Pleiades and Messier 45 will be positioned within a binoculars' field of view above (celestial north of) the moon. Scan your binoculars below (south of) the moon to see the bright star Aldebaran at the corner of the V-shaped stars that form the face of the bull. Those stars, known as the Hyades Cluster and Caldwell 41, are one of the closest open star clusters to Earth.

Friday, December 17 - Venus Closest to Saturn and Jupiter (after sunset)

(Image credit: Starry Night)

On the evenings around Friday, December 17, the planet Venus will reach its minimum angular separation from Jupiter and Saturn. Those three bright planets will share the southwestern sky after dusk — with bright Venus gleaming 31 degrees to the lower right (celestial west) of Jupiter, and somewhat fainter Saturn positioned midway between them. After tonight, Venus will swing sunward and pull away from Jupiter and Saturn.

Saturday, December 18 - Crater Copernicus (all night)

december 2021 night sky Crater Copernicus

(Image credit: Starry Night)

The prominent crater Copernicus is located in eastern Oceanus Procellarum — due south of Mare Imbrium and slightly northwest of the moon's centre. This 800 million year old impact scar is visible with unaided eyes and binoculars — but telescope views will reveal many more interesting aspects of lunar geology. Several nights before the moon reaches its full phase, Copernicus exhibits heavily terraced edges (due to slumping), an extensive ejecta blanket outside the crater rim, a complex central peak, and both smooth and rough terrain on the crater's floor. Around full moon, Copernicus' ray system, extending 500 miles (800 km) in all directions, becomes prominent. Use high magnification to look around Copernicus for small craters with bright floors and black haloes - impacts through Copernicus' white ejecta that excavated dark Oceanus Procellarum basalt and even deeper highlands anorthosite. 

Sunday, December 19 - Full Oak Moon (at 04:35 GMT)

december 2021 night sky Full Oak Moon

(Image credit: Starry Night)

The December full moon will occur at 04:35 GMT on Sunday, December 19, which converts to 11:35 p.m. EST on Saturday evening. Traditionally known as the Oak Moon, Cold Moon, and Long Nights Moon, it always shines in or near the stars of Gemini. The Ojibwe of the Great Lakes region call the December full moon Manidoo Giizisoons, the "Little Spirit Moon". For them it is a time of purification and of healing of all Creation. Since it's opposite the sun on this day of the lunar month, the moon is fully illuminated and rises at sunset and sets at sunrise. Full moons during the winter months reach as high in the sky at midnight as the summer noonday sun, and cast similar shadows.

Tuesday, December 21 - Northern Winter Solstice (at 15:59 GMT)

december 2021 night sky Northern Winter Solstice

(Image credit: Starry Night)

Winter in the Northern Hemisphere will officially commence on Tuesday, December 21 at 15:59 GMT (or 10:59 a.m. EST and 7:59 a.m. PST). At that time the sun will reach the solstice - its southernmost declination for the year, resulting in the lowest noonday sun, the shortest amount of daylight of the year for the Northern Hemisphere, and the longest amount for the Southern Hemisphere. After the December solstice, the daylight hours will begin to increase for the Northern Hemisphere.

Wednesday, December 22 - Ursids Meteor Shower Peak (pre-dawn)

december 2021 night sky Ursids Meteor Shower Peak

(Image credit: Starry Night)

The annual Ursids meteor shower, produced by debris dropped by periodic comet 8P/Tuttle, runs from December 13 to 24. The short shower will peak during the early hours of Wednesday, December 22, when seeing 5 to 10 meteors per hour is possible under dark skies. The best time to watch will be the hours before dawn. A waxing, half-illuminated moon will have set at around midnight, leaving the sky nice and dark for seeing meteors. True Ursids will appear to radiate from a position in the sky above the Little Dipper (Ursa Minor) near Polaris, but the meteors can appear anywhere in the sky. 

Saturday, December 25 - A Christmas Star (late evening)

december 2021 night sky A Christmas Star

(Image credit: Starry Night)

Sirius, the brightest star in Canis Major, and the brightest star in the sky (after the sun) rises in the southeast by 7 p.m. local time. It's hard to miss. The star will climb to its highest point, about a third of the way up the southern sky, shortly after midnight. If you are walking through your darkened house in the middle of the night, Sirius will probably catch your eye out a window because it never climbs very high. Sirius is a hot, blue-white, A-class star located only 8.6 light-years from the sun. Its extreme brightness and its low position in the sky combine to produce spectacular flashes of color as it twinkles. A very large telescope may allow you to see Sirius B, a faint white dwarf companion located 10 arc-seconds east from Sirius.

Sunday, December 26 - Mars Passes its Rival (pre-dawn)

december 2021 night sky Mars Passes its Rival

(Image credit: Starry Night)

Low in the southeastern pre-dawn sky on the mornings surrounding Sunday, December 26, the motion of the red planet Mars (red path with date:time) will carry it past its "rival", the bright star Antares in Scorpius. At its closest approach on December 27, Mars will shine several finger widths to the upper right (or 4.5 degrees to the celestial north) of the star, but they'll be binoculars-close (green circle) from December 23 to 31, with Antares shifting higher each morning. Antares will appear slightly brighter than the planet, but it will exhibit a similar reddish color - hence their rivalry! The optimal viewing time at mid-northern latitudes will be around 6:30 a.m. local time. Observers at southerly latitudes will see the duo shining higher, in a darker sky.

Monday, December 27 - Third Quarter Moon (at 02:23 GMT)

december 2021 night sky Third Quarter Moon

(Image credit: Starry Night)

When it reaches its last quarter phase at 02:23 GMT on Monday, December 27 (or 9:23 p.m. EST on Sunday), the moon will rise at about midnight, and then remain visible in the southern sky all morning. At last quarter, 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. The week of moonless evening skies that follow last quarter will be ideal for observing deep sky targets.

Tuesday, December 28 - Inner Planets Dance (after sunset)

december 2021 night sky Inner Planets Dance

(Image credit: Starry Night)

For about an hour after sunset on the evenings surrounding Tuesday, December 28, look low in the southwestern sky for a conjunction of Mercury and Venus. Each night, magnitude -0.7 Mercury will be ascending, while 31 times brighter Venus drops sunward. At their closest on December 28, Mercury will be positioned several finger widths to the lower left (or 4.25 degrees to the celestial south) of Venus, close enough to share the view in binoculars (green circle). Seen in a telescope, Venus will show a slim crescent phase. But Mercury will appear nearly fully-illuminated because Venus is closer to Earth than the sun, while Mercury is on the far side of the solar system. Take care to avoid pointing optical aids west until the sun has fully set.

Friday, December 31 - Old Moon near Mars and Antares (pre-dawn)

december 2021 night sky Old Moon near Mars and Antares

(Image credit: Starry Night)

Low in the southeastern sky on the morning of Friday, December 31, the slim crescent of the old moon will shine above and between the reddish dot of Mars and the bright star Antares. The trio, with Mars on the left (celestial east), will be less than 5 degrees apart, close enough to share the view in binoculars (green circle). You can observe them from the time they rise, at about 5:30 a.m. local time, until sky brightens before sunrise. At about 18:30 GMT on Friday morning, observers in parts of southern Australia, Tasmania, Antarctica, the South Georgia Islands, the southern tip of South America, and the Falkland Islands can see the moon occult Mars.


(Image credit: Starry Night)

Following its superior conjunction with the sun at the end of November, Mercury will enter the western post-sunset sky in December. But for mid-northern latitude observers, its position several degrees south of the plane of the south system, plus the severely tilted evening ecliptic, will prevent the swift planet from climbing out of the bright twilight until the second half of December. Observers in the tropics and in the Southern Hemisphere will see Mercury somewhat earlier in the month. On December 29, Mercury will pass 4 degrees to the south of much brighter Venus — but they'll be binoculars-close from December 27 to 30. The best viewing period for those inner planets will start at around 5 p.m. local time — but you'll need a cloud-free, unobstructed southwestern horizon. Viewed in a telescope during the latter part of December, Mercury will show a waning gibbous phase and a disk diameter that swells to 5.9 arc-seconds at month's end. Ensure that the sun has fully set before turning optics toward Mercury.

(Image credit: Starry Night)

After a lengthy stay in the western sky during early evening, Venus will spend December swinging sunward. The increasingly upright ecliptic will finally let the planet shine in a darkened sky for mid-northern latitude viewers. On December 3, Venus will reach its maximum brightness of magnitude -4.66 for the current apparition. Viewed through a telescope during December, our sister planet will show a waning crescent phase that will end December as a mere 2.5%-illuminated sliver! Meanwhile, Venus' apparent disk diameter will swell dramatically from 38.7 arc-seconds to 1 arc-minute. Venus will move prograde eastward through the stars of eastern Sagittarius until December 18, and then it will enter a retrograde motion period. On December 29, Mercury will pass 4 degrees to the south of much brighter Venus — but they'll be binoculars-close from December 27 to 30. (Be sure to wait until the sun has fully set before turning optics towards either planet.) On December 6 the slim crescent of the young moon will shine 3 degrees to the south of Venus, close enough for them to share the view in binoculars. On the evenings around December 17, Venus will reach its minimum angular separation from Jupiter of 31 degrees - with Saturn positioned between them. 

december 2021 night sky mars

(Image credit: Starry Night)

During December, magnitude 1.62 Mars will become observable in the southeastern pre-dawn sky as it slowly climbs away from the sun. Viewed in a telescope in December, the red planet will display a modest 4 arc-seconds-wide disk. In December Mars will be beginning its year-long trek to a bright opposition in December, 2022. In the interim, it will pass very close to many planets and deep sky targets. On December 1, the planet will rise in central Libra at about 5:30 a.m. local time. The following morning, the slim crescent of the old moon will shine 7 degrees to the northwest of it. Observers in most of Mongolia, northeastern China, parts of eastern Russia, Japan, most of Micronesia, northern Polynesia, and Hawaii can see the moon occult Mars. The planet's eastward prograde motion will carry it into Scorpius on December 16. After passing between the scorpion's claw stars Acrab and Dschubba, and very close to the wide double star Omega1,2 Scorpii on December 18-19, Mars will shine only 1.6 degrees north of the globular cluster Messier 80 on December 23. It will pass less than 5 degrees north of its rival, the reddish star Antares on December 27-28, and then end the month in eastern Ophiuchus. The old crescent moon will shine less than 5 degrees to the west of Mars on December 31.

december 2021 night sky jupiter

(Image credit: Starry Night)

The earlier sunsets of December will extend evening Jupiter-viewing time. Look for the planet shining as a very bright, white dot in the lower third of the southern sky after dusk. It will sink below the west-southwestern horizon at around 10 p.m. local time on December 1 and then before 9 p.m. by month's end. All month long Jupiter will travel prograde eastward, starting December above the Sea-Goat's tail stars in eastern Capricornus and then entering next-door Aquarius on December 14. Fainter, yellow-hued Saturn, shining to Jupiter's west, will increase its separation from Jupiter by 2 degrees, to 18.5 degrees on December 31. Views of Jupiter in amateur telescopes will show dark equatorial bands across its disk, which will shrink in size from 38.2 to 35.3 arc-seconds during the month. The Great Red Spot will appear for a few hours every 2nd or 3rd night. Two of the round, black shadows of Jupiter's Galilean satellites will cross Jupiter's disk, one of them with the Great Red Spot, on December 10. From December 8 to 9, the crescent moon will move past Jupiter. On the evenings around December 17, Venus will close to within 31 degrees of Jupiter - with Saturn positioned between them.

(Image credit: Starry Night)

During December, Saturn will become visible after dusk as a creamy-colored, magnitude 0.7 object shining to Jupiter's lower right in the lower part of the southwestern sky. But the ringed planet will become less satisfying as a telescope target when its elongation from the sun decreases toward year end. Compared to the stars of western Capricornus that surround it, Saturn will be treading slowly eastward all month. Viewed in a telescope, Saturn will display a mean apparent disk diameter of 15.7 arc-seconds, and its rings will subtend 36.6 arc-seconds. Several moons can be readily seen arrayed around the planet, especially the brightest one, Titan, which takes 16 days to complete an orbit. Saturn's rings will be tilting more edge-on to Earth every year until the spring of 2025. This year they are already closed enough for Saturn's southern polar region to extend beyond them. On December 7 to 8, the crescent moon will pass 5 degrees to the celestial south of Saturn.

december 2021 night sky uranus

(Image credit: Starry Night)

Magnitude 5.7 Uranus will be observable in binoculars and telescopes from after dusk until the wee hours during December. Its small, blue-green dot will be moving slowly retrograde westwards in southern Aries, 11.5 degrees southeast of that constellation's brightest stars, Hamal and Sheratan — and only 5 degrees from the star Mu Ceti to its south. On December 14 and 15, the very bright and nearly-full moon will shine to the southwest and southeast of Uranus, respectively.

(Image credit: Starry Night)

The distant and blue-colored planet Neptune will be observable in the southwestern sky in evening during December while the magnitude 7.9 planet travels very slowly eastward among the stars of northeastern Aquarius. If the sky is very dark, Neptune can be seen in binoculars. To locate it, find the north-south grouping of five medium-bright stars Psi, Chi, and Phi Aquarii (or ψ, X, and φ Aqr). Neptune's non-twinkling speck will sit 3 degrees to the NNE of the top star, Phi. Viewed in a telescope, Neptune's apparent disk size will be 2.3 arc-seconds. Your best views will come immediately after dusk, when the blue planet will be highest in the south.

Skywatching Terms

Gibbous: Used to describe a planet or moon that is more than 50% 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.

Further Reading

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Chris Vaughan
Chris Vaughan, aka @astrogeoguy, is a geophysicist and lifelong amateur astronomer based in Toronto, Canada. He is an active member of the Royal Astronomical Society of Canada, and an operator of the historic 74˝ telescope at the David Dunlap Observatory. Highly active in science public outreach and education, he frequently organizes local star parties and sidewalk solar astronomy sessions, and regularly delivers presentations about astronomy, and earth and planetary science, to students and the public. For more than three years, he has published Astronomy Skylights, a weekly newsletter which is accessible through Tumblr, Facebook, and Google+. He writes the Mobile Stargazing column for in cooperation with SkySafari software.
  • Malcolm
    Hi MMohammad,
    Thank you for your gracious welcome via email, though I fear we are ‘light years’ away from each other (as my comment shows, if it stays and is not censored) when it comes to this Earth and the Universe in which we live. I am no expert but each to their own beliefs.