What's Up

Your monthly video guide to the night sky from NASA
Each month, NASA's skywatching video series shares highlights to help you prepare for your stargazing adventures and feel more connected to the real places NASA explores.

A sky filled with stars over a desert landscape.

What's Up for December 2023


Vesta at Opposition and Geminid Meteors!

The most reliable meteors of the year are here, with no interference from a bright Moon. The Geminids peak overnight on the 13th into the morning of the 14th. And if you'd like to add "asteroid observer" to your list of accomplishments, try your hand at observing Vesta with binoculars or a small telescope.

December skywatching highlights:

  • December 7-10 – Catch the slimming crescent of the Moon each morning over four days, as it rises together with Venus and bright star Spica, in the east during the couple of hours before sunrise.
  • December 12 – New moon
  • December 13 – The Geminid meteors peak overnight tonight. Northern Hemisphere observers can look for meteors as early as 9 or 10 p.m., with the hourly number increasing after midnight. Dress warmly, get away from bright lights, and take in as much of the sky as possible. Meteors will fall all over the sky.
  • December 17 – Following sunset, look for the crescent Moon super close to Saturn in the southwest. Binoculars or a small telescope can reveal Saturn's giant moon Titan as a faint dot right next to the planet.
  • December 21 – Jupiter appears close to the nearly full Moon in the southeast as darkness falls. Watch them glide across the sky together all night.
  • December 26 – Full moon
  • All month – Asteroid Vesta is at opposition, meaning it is directly on the opposite side of Earth from the Sun, and at its closest and brightest for the year. This is a good time to try viewing it with binoculars or a small telescope. Look for it to move northward in the sky between Gemini and Orion during the month. USe your favorite skywatching app to locate its precise position on the night you're observing.
An illustrated sky chart shows the predawn sky facing southeast, 1 hour before sunrise on December 7 through 10, 2023. An increasingly slim crescent Moon is seen in four locations on the sky over these four mornings, moving from above and to the right of Venus (represented with a bright white dot) on the 7th, to directly below Venus on the 10th. The star Spica appears as a white dot above and right of Venus, and the Moon is closest to Spica on December 8.
Sky chart showing the crescent Moon with Venus on the mornings of December 7-10.

Video Transcript

Text of the current month's video.

What's Up for December? The best views of the Moon and planets, the Geminid meteors are set for a great show, and a chance to observe an asteroid with your own eyes.

The Moon visits the bright planets in the sky, in turn, over the course of the month, beginning with four mornings in early December – the 7th through the 10th – when you can catch a lovely grouping of Venus, the crescent Moon, and bright star Spica in the southeast.

Then on the 17th, you'll find the crescent Moon hanging just below Saturn in the southwest for the first few hours after sunset. Most binoculars will reveal both of them in the same field of view. And for a challenge, see if you can spot Saturn's giant moon Titan as a faint dot just off to the planet's side here.

Sky chart showing the crescent Moon with Saturn on the evening of December 17.

Later that week, the nearly full moon hangs out with Jupiter over two nights on the 21st and 22nd. You'll see them toward the southeast early in the night, and they travel westward across the sky together all night long.

The year's most reliable meteor shower, the Geminids, takes place annually in December. While the Perseids tend to get a bit more attention because they occur during warmer weather in the Northern Hemisphere, the Geminids usually produce more meteors. At their peak, you may even see a meteor every minute.

The shower peaks overnight on December 13 and the morning of the 14th. Viewers in the Northern Hemisphere can look for meteors as early as 9 or 10 p.m. on the 13th. The hourly number of meteors should increase after that, with the greatest number flashing through the sky between midnight and morning twilight.

Southern Hemisphere skywatchers can also see the Geminids, though they appear in the middle of the night, and at about a quarter of the Northern rate.

If you have clear skies, conditions should be ideal for this year's peak night, which is just one day after the new moon, leaving the sky nice and dark all night. The meteors appear to radiate from the constellation Gemini, but you'll see more shooting stars if you look straight overhead and take in as much of the sky as possible.

An illustrated sky chart shows the constellation Gemini (at lower left) and the upper part of Orion (at upper right). A diagonal line in the sky between Orion and one of the legs of the Gemini twins is labeled "Vesta, December 1 to December 20."
Sky chart showing the movement of asteroid Vesta during December.

Want to see an asteroid with your own eyes? Asteroid Vesta reaches opposition this month, meaning it's located directly on the opposite side of Earth from the Sun. This is also around the time Vesta is closest to Earth, so it's at its brightest and easiest to observe.

Occasionally Vesta is close enough to Earth at opposition that you can almost see it with your eyes alone. But this year, you'll want to use binoculars or a small telescope to search it out.

NASA's Dawn spacecraft got super close to Vesta, orbiting the oval-shaped world in 2011 and 2012. It found that Vesta formed in our solar system's first couple of million years, and mapped the surface in great detail.

This December, Vesta is highest overhead around 1 or 2 in the morning (which is ideal for telescope viewing), but you can observe it as early as about 10pm, when it will appear about halfway up the eastern sky.

An illustrated sky chart shows two bright stars in Gemini, Tejat (at left, below center) and Propus (at left, above center) that lie on the "leg" of Castor (one of the Gemini twins from mythology). A dashed line connects each of the stars to the star Betelgeuse, offscreen to the right. Along each line is a point labeled "Vesta, December 1," (at right, below center) and "Vesta, December 8" (at right, above center).
Sky chart showing the location of asteroid Vesta on December 1 and December 8. On these nights, Vesta will be easy to find along a line between Betelgeuse in Orion and one of two bright stars in Gemini.

Locate Vesta in between the raised arm of Orion, here, and the leg of Castor in Gemini, here. On December 1st, you can find Vesta along a line between Betelgeuse and this star, Tejat. A week later Vesta has moved so that it appears along this line between Betelgeuese and Propus, here. A plain old pair of binoculars should reveal Vesta a couple of finger widths to the west of these two stars. Use your favorite skywatching app as a guide to Vesta's location within the starfield you see on whatever night you're observing.

And if you're hungry for more asteroid exploration, there's more on the way! NASA's Psyche mission recently launched on its journey to metal-rich asteroid Psyche, and our Lucy spacecraft just flew past asteroid Dinkinesh with its little satellite asteroids, at the start of November. Lucy is heading for the Trojan asteroids, a unique family of space rocks that share Jupiter's orbit and are likely to be remnants of the same primordial material that formed Jupiter and the other outer planets.

And if that sounds interesting to you, maybe you're ready to add "asteroid observer" to your list of accomplishments, as you look for Vesta in the December sky.

Here are the phases of the Moon for December.

The main phases of the Moon are illustrated in a horizontal row, with the third quarter moon on December 5, new moon on December 12, first quarter on December 19, and full moon on December 26.
The phases of the Moon for December 2023.

Stay up to date on NASA's missions exploring the solar system and beyond at science.nasa.gov. I'm Preston Dyches from NASA's Jet Propulsion Laboratory, and that's What's Up for this month.

Skywatching Resources

About the What's Up production team

"What's Up" is NASA's longest running web video series. It had its first episode in April 2007 with original host Jane Houston Jones. Today, Preston Dyches, Christopher Harris, and Lisa Poje are the science communicators and space enthusiasts who produce this monthly video series at NASA's Jet Propulsion Laboratory. Additional astronomy subject matter guidance is provided by JPL's Bill Dunford, Gary Spiers, Lyle Tavernier, and GSFC's Molly Wasser.

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