You are here: Home USNO News, Tours & Events Sky This Week The Sky This Week, 2016 December 13 - 20
The USNO websites,,,,,, and are undergoing modernization efforts. The expected completion of the work and the estimated return of service is Fall 2020, subject to change due to potential impacts of COVID-19.

The Sky This Week, 2016 December 13 - 20

The last men on the Moon.
Moonrise over Northeast DC, 2016 December 12,
imaged from the dome of the 12-inch telescope, USNO, Washington, DC

The Full Moon begins the week among the bright stars of the Great Winter Circle, then moves eastward into the rising stars of spring. constellations. Last Quarter occurs on the 20th at 8:56 pm Eastern Standard Time. Look for the Moon just north of the second-magnitude star Alhena in the constellation of Gemini on the evening of the 14th. Early risers can see her Night near the bright star Regulus before dawn on the morning of the 18th.

Take a few moments to glance at the Moon sometime this week. It was 44 years ago that the last manned exploration of Luna was carried out by the crew of Apollo 17. Navy Captains Eugene Cernan and Ron Evans, along with geologist Harrison Schmidt spent six days in the Moon’s vicinity. Cernan and Schmidt spent three days exploring the lunar surface near the crater Littrow, driving over 35 kilometers (22 miles) across the rugged terrain in their Lunar Rover and collecting 110 kilograms (243 pounds) of rock and soil samples. Evans remained in the Command Module, obtaining high-resolution photographs and gamma-ray observations from lunar orbit. The last foot prints were left on the Moon’s surface by CAPT Cernan on December 13th, 1972. The mission concluded with a successful recovery on December 19th. Since those heady days of the Apollo program I have always looked at the Moon a little differently. It is the only other place in the universe that we have visited "in person", and it always makes me think about just how special and fragile our home planet is.

Sharing the sky with the Moon early in the week are the bright stars of the Great Winter Circle. These stars stubbornly resist the glare of the nearly-full Moon and add a touch of multi-hued lighting to the long winter solstice nights when Luna is absent. Centered on the distinctive constellation of Orion, the Circle consists of some of the sky’s brightest stars. Start your trip around the Circle with Sirius in Canis Major, the brightest star in the sky, whose icy-blue glimmer lies southeast of Orion’s distinctive belt. Moving northward you’ll encounter Procyon in Canis Minor, then Castor and Pollux, the Twin Stars of Gemini. Moving westward you’ll see golden Capella in Auriga, then, to the southwest, you’ll encounter Aldebaran, the ruddy eye of Taurus. Complete the circle with blue-hued Rigel marking one of Orion’s knees. Within the confines of this circle you’ll find nine of the 25 brightest stars in the sky!

Venus is now almost impossible to miss in the evening sky. By the end of the week she sets two hours after the end of evening twilight, so you’ll have a very nice view of her against a dark sky background. If you can get far enough away from the city during the upcoming holidays, try to look for your shadow cast by her brilliant glow.

Mars is patiently plodding eastward against the faint stars of Capricornus and after Venus is the brightest object in the southwestern sky during the early evenings. He’s got an eye out for the approach of the dazzling planet, but she won’t quite catch him before she swings toward the Sun early next year.

Jupiter remains an early morning sight, well-laced in the eastern sky for a quick look through the telescope before sunrise. You’ll find him in the vicinity of Spica, the brightest star in the constellation of Virgo.

USNO Master Clock Time
Javascript must be Enabled