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 Vaughn 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.
Sky Maps and Video Guides
Best Night Sky Events of December 2016 (Stargazing Maps)
See what's up in the night sky for December 2016, including stargazing events and the moon's phases, in this Space.com gallery courtesy of Starry Night Software.
Venus and Mars After Sunset, Geminids 'Rain' And More In Dec. 2016 Skywatching | Video
Venus and Mars can be viewed in the southwestern skies after sunset. The Perseus and Cassiopeia constellations are excellent skywatching targets. Also in mid-December, the Geminid meteor shower will peak.
Wednesday, December 7 at 4:03 a.m. EDT - First Quarter Moon
At first quarter, the positions of the Earth, sun, and moon cause us to see one-half of the moon illuminated by the sun. The moon's bright half is on the western (right-hand) side - toward the setting sun. It rises around noontime and sets around midnight, so the moon is visible half the time by day – in the afternoon hours – and the other half at night, during the evening hours. The name quarter moon, even though it's really a "half-moon" shape, refers to the fact that, starting from new moon, our natural satellite has now completely the first quarter of its orbital journey around Earth.
Tuesday, December 13 at 7:05 p.m. EDT - Full Oak/Cold/Long Nights Moon, a Supermoon, and High Tides
The December full moon, known as the Oak Moon, Cold Moon or Long Nights Moon, always shines in or near the stars of Taurus. It rises around sunset and sets around sunrise; this is the only night in the month when the moon is in the sky all night long. The rest of the month, the moon spends at least some time in the daytime sky. This month's full moon occurs only one day after the moon reaches perigee, the point in its orbit closest to earth. As a result, this full moon will appear slightly larger and brighter, sometimes referred to as a supermoon, and we'll also experience extra high tides. This full moon coincides with the peak of the Geminid meteor shower, spoiling the show.
Tuesday, December 20 at 8:56 p.m. EDT - Last Quarter Moon
After full phase, the moon is now waning, illuminated less every evening. At last quarter the moon rises around midnight and sets near noon. Morning commuters might take note of it, shining high in the south against the blue daytime sky. The bright half is now on the left-hand side, towards the eastern dawning sun. At last quarter, the moon is positioned ahead of the Earth in our trip around the sun. When you see it in the sky, keep in mind that about 3½ hours later, earth will occupy the same point in space where the moon is now. After last quarter, the moon begins to traverse the last quarter of its orbit in its trip around the earth as it approaches new moon.
Thursday, December 29 at 1:53 a.m. EDT - New Moon
The moon's orbit carries it between the earth and sun and sits in the same region of the sky where the sun is. Sunlight is only reaching the side of the moon that is turned away from us, so as a consequence it cannot be seen. Starting a day or two after new moon, you might catch a glimpse of the slender sliver of a waxing crescent moon low near the western horizon, as it gradually pulls away from the sun's vicinity and shifts toward the east.
Thursday, December 1 at dusk – New Moon over Mercury
Immediately after sunset on Thursday, December 1, look low in the western sky for the slim crescent moon sitting 9 degrees above (to the northeast of) Mercury. Mercury sets at 5:40 pm local time, about an hour after the Sun, and the moon sets at 6:45 pm local time.
Friday, December 2 evening – Asteroid Vesta begins Retrograde Motion
On Saturday, December 2, the large asteroid Vesta stops moving eastward and commences westward retrograde motion in the sky. In December, it rises in the east in mid-evening near the Beehive Cluster in Cancer, and remains visible most of the night. At apparent magnitude 3.2, it is observable with naked eyes, binoculars, and small telescopes, and its motion through the background stars can be seen by observing it on separate evenings.
Friday, December 2 evening – Crescent Moon near Venus
In the western sky after sunset on Friday, December 2, the crescent moon will be sitting 8 degrees to the right, and slightly above, the bright planet Venus. Both objects set about 7:40 pm local time.
Sunday-Monday, December 4-5 evening – Moon hops over Mars
On the evenings of Sunday and Monday, December 4 and 5, the waxing crescent moon hops eastward over Mars in the southwestern sky. On Sunday, the moon sits 6 degrees to the right of Mars. The following evening, it jumps to sit 6 degrees to the upper left of the red planet. Mars sets about 9:45 pm local time.
Tuesday, December 6 from 5 pm EST – Neptune near the Moon and Occultation for Central America, USA, Eastern Canada, North Atlantic, Western Europe
On Tuesday, December 6, for observers in Central America, continental USA, Eastern Canada, North Atlantic, and Western Europe, the first quarter moon will occult Neptune. In the northeastern USA, both objects are in Aquarius, above the southern horizon, but the event will start before darkness sets in. The dark leading edge of the moon will cover Neptune at 4:10 pm Eastern Time. Then, at 5:30 pm Eastern Time, the blue planet will emerge from behind the moon's opposite lit edge. Observers outside the Eastern Time zone should adjust these times for their own time zone. The rest of the world will only see the Moon pass near the planet.
December 10-11, 2016 after dusk - Mercury at Greatest Eastern Elongation
On Monday, Dec. 10 and Tuesday, December 11, at dusk, Mercury will be observable in the western sky for about half an hour after sunset. With Mercury south of the shallow ecliptic, this apparition is less than ideal for the northern hemisphere, but very good for the southern hemisphere.
Monday, December 12 evening – Moon traverses the Bull's Face and Occults Aldebaran
Overnight on Monday, December 12, the nearly full moon will traverse the triangular face of Taurus the Bull. Observers in Northern Mexico, the continental USA, Southeastern Canada, Western Europe, and Northwestern Africa will also see the moon occult the bright naked eye star Aldebaran, which marks Taurus' eye. In the northeastern USA, look high in the southwestern sky, where the moon's dark leading limb will cover the star at approximately 11:12 pm Eastern Time. Aldebaran will emerge from behind the opposite lit limb around 12:26 am. Observers outside of the Eastern Time Zone should adjust for their local time zone (and times vary slightly by latitude). Observers elsewhere will only see the moon pass close to the star.
Tuesday–Wednesday, Dec. 13–14, midnight to dawn - Geminid Meteor Shower
The Geminid meteor shower, one of the most reliable in the year, runs from December 4 to 16. It peaks on the evening of Tuesday, Dec. 14, so the best time to observe will be from sunset Tuesday until dawn on Wednesday morning. Unfortunately, the moon will be full on the peak evening, and sitting near the shower's radiant.
Thursday, December 15 evening – Asteroid Ceres ends Retrograde Motion
On Thursday, December 15, the large asteroid Ceres ends its westward retrograde motion in the sky and resumes its normal eastward travel. In December, it sits below the stars of Pisces, in the southeastern sky at dusk and sets well after midnight. At apparent magnitude 4.95, it is observable with binoculars and small telescopes, and its motion through the background stars can be seen by observing it on separate evenings.
Saturday-Sunday, December 17-18 evening – Old Moon hops over Regulus
Visible from late evening through dawn on both Sunday and Monday, December 17 and 18, the waning gibbous moon will hop over the naked eye star Regulus in Leo. The moon will be about 6.5 degrees above Regulus on Sunday, and a similar distance below the star on Monday. On both dates, Regulus rises in the east around 9:30 pm local time and is due south by 4:30 am local time.
Wednesday, December 21 at 5:44 a.m. EST - Winter solstice
On Wednesday, December 21 at 5:44 a.m. EST, the sun reaches its southernmost declination for the year, resulting in the shortest day of the year for the northern hemisphere and the longest day of the year for the southern hemisphere.
Wednesday-Thursday, December 21–22 midnight to dawn - Ursid Meteor Shower
The Ursid meteor shower runs from December 17 to 23. It peaks in the wee hours of Thursday, December 22, so the best time to observe will be from midnight to dawn that morning. The moon will be a waning crescent in the sky during the peak. The shower's radiant is above the Little Dipper (Ursa Minor) near Polaris.
Thursday, December 22 morning – Crescent Moon meets Jupiter
In the eastern pre-dawn sky from 1:30 am to dawn on Thursday, December 22, the waning crescent moon will sit less than 5 degrees west of (above) Jupiter. Both bright objects will be easy to see with naked eyes. The following morning, the moon will be 7.5 degrees below Jupiter.
Tuesday, December 27 dawn – Old Moon meets Saturn
In late December, the ringed planet Saturn will be sitting very low in the southeastern sky before dawn. On Tuesday, December 27, the old crescent Moon will sit only 5 degrees to the northwest of (above) the planet. The best viewing times are between 6:15 and 7:15 am local time.
As December opens, Mercury has commenced an evening apparition. This is a poor one for northern hemisphere observers (the planet's orbital inclination has carried it below an already shallow ecliptic), but an excellent one for southern hemisphere viewers. Its visibility worldwide improves as the planet swings wider of the sun until December 11 when it reaches greatest eastern elongation. Then it begins to slide sunwards again. By the time it disappears from view around the third week of December, it has dimmed and waned to a slim crescent phase. It reaches inferior conjunction with the sun on December 28. (image: Dec 10 at 5 pm Mercury Greatest Eastern Elongation.jpg)
Venus spends December approaching, but not quite reaching, its greatest eastern elongation, as it shines brilliantly in the western early evening sky. As it swings wider of the sun, it is also being carried higher as the ecliptic's angle with the western evening horizon increases. Meanwhile, it is waning gradually in phase, and brightening - to a visual magnitude of -4.34 by month's end. Venus spends all but the opening and closing days of December amid the stars of Capricornus. After sunset on December 2 and 3, the young crescent Moon will pass to the north of Venus, sitting 8 degrees northwest (to the right) of Venus on the 2nd and 6.5 degrees above (to the northeast of) Venus on the 3rd.
On December 15, Mars' eastward motion carries it from Capricornus and into Aquarius. Through the month, it decreases in brightness and disk size as we increase our distance from it. But it remains an easily visible bright reddish object in the evening southwestern sky, setting at 9:30 pm local time all month long. On December 4 and 5, the waxing crescent moon will pass to the north of Mars, landing about 6 degrees to the lower right and upper left of the red planet respectively.
Jupiter, in Virgo, is a pre-dawn object in December, rising at 2:30 am on December 1 and at 1 am local time by month's end. Every day, it is being carried higher in the eastern sky by the Earth's motion around the Sun while, at the same time, it's regular prograde motion eastward is slowly moving in it the opposite direction. The bright planet is easy to see, even as the sky becomes lighter before sunrise. On Thursday, December 22, in the eastern pre-dawn sky from 1:30 am to dawn, the waning crescent moon will sit less than 5 degrees west of (above) Jupiter. The following morning, the moon will be 7.5 degrees below Jupiter.
Saturn begins December hidden by the western dusk twilight, as it approaches conjunction with the Sun on December 10. It resumes visibility low in the eastern morning skies after mid-December. On Tuesday, December 27, the old crescent Moon will land only 5 degrees to the northwest (above) the planet. The best viewing times are between 6:15 and 7:15 am local time.
Uranus is in the southeastern evening sky in the constellation of Pisces throughout December. It's visible through most of the night but as December closes, the planet sets by 1 am local time. At magnitude 5.8, it is not readily visible with unaided eyes, but binoculars or a small telescope can reveal its tiny blue-green dot. If you compare its position with the surrounding stars, you'll notice that it is moving retrograde, or westward until December 29, when it resumes normal prograde motion. (image: Uranus December.jpg)
Neptune is in the southwestern evening sky in the constellation Aquarius. It is a very dim, nearly 8th-magnitude object visible only with very good binoculars or a telescope. In early December it is observable from nightfall until about midnight, but it sets around 9:30 pm local time at month's end. On Tuesday, December 6, for observers in Central America, the continental USA, Eastern Canada, the North Atlantic, and Western Europe, the first quarter moon will occult Neptune. The rest of the world will only see the moon pass near the planet.(image: Neptune December.jpg)
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.