Sky Report - December 2008

Planets-Moon Line Up, Long Night Moon & Winter Stars Return

The first few days of December 2008 offer a special sky sight at the onset of darkness (5:15 to 5:45 p.m.). Look low in the Southwest (to the left of where the sun earlier set) for a line up of the two brightest planets, Venus and Jupiter. These appear as bright points of light that shine steadily. Even the nearest planets appear as points for their distances are always at least 100 times farther away than our moon. (Our moon is about a quarter of a million miles away from Earth.) Venus outshines Jupiter due to its closeness both to the sun and Earth. The giant planet Jupiter is more than 6 times as far from the Earth as Venus and also about 6 times as far from the sun as Venus. The two planets in early December are about 2 degrees apart, about four times the angular width of the moon. But on the night of December 1st, the crescent moon will appear just to the left of the planet pair.

By December 5th, the evening moon will appear half full. Around this date, the evening moon will offer its best viewing of its craters and mountain ranges through binoculars or a telescope. Along the moon’s straight (left) edge, the sun there is rising, lighting up the raised crater rims and mountain peaks. The evening moon grows to full on December 12th. This is called the Long Night Moon as this full moon has the highest sky path of any full moon this year. For the full moon has the nearly the same position along zodiac as the summer sun has six months later. So our December full moon has about the sky track as the June sun that shines for nearly 15 hours each day. The moon will appear near the planet Saturn in the early morning hours of December 18th and 19th. By the 19th, the moon will have shrunk to half full, seen as a backwards “D” in the southern dawn. The moon is new on Christmas day, then swinging from the morning to the evening side of the sun. In the twilight hours of December 29th, a slender crescent moon appears low in the southwestern dusk near the planet Jupiter. On New Year’s evening, the crescent moon and Venus pair off in the southwestern dusk.

In the evening hours of December, the bright winter evening stars begin appearing in the East. The first arrival is the bright golden star Capella in the Northeastern sky. To the right of Capella is the Pleiades or Seven Sisters star cluster, resembling a tiny dipper (but not the Little Dipper). Below the Seven Sisters star cluster is the bright orange star Aldebaran, marking the eye of Taurus, the Bull. Later in the evening, the bright star group Orion surfaces in the East. Orion’s trademark feature is his belt of three stars in a row. The remaining four bright stars form a tilted rectangle with the belt in the middle. Orion’s brightest star is Rigel, shining to the right of the belt. Even later in the evening, the blazing star Sirius appears below Orion. Orion’s belt points down to Sirius. Sirius has two titles; it’s the closest night star we can see and it is the brightest night star. High in the North is the star group Cassiopeia that resembles a stretched out letter “M”.

The December program at the Frostburg State Planetarium is “Skies of the Holy Lands” with free public presentations on Sundays on December 7th, 14th and 21st. Our show times are 4 p.m. and 7 p.m. Our programs begin with an informal tour of the current evening sky and good sights in the months ahead. The Planetarium is in Tawes 302. Tawes Hall is near the FSU Clock Tower, the Lane University Center and the Performing Arts Center (where many recitals, plays and musicals are staged). Park in the Performing Arts parking area and walk around the Performing Arts building to the right. Several hundred feet away on the left is Tawes Hall. To the right is the larger Compton Science Center. Call (301) 687-7799 to request a free bookmark (that includes a small map showing all these buildings); please leave your name and mailing address.

To contact Dr. Doyle, his mailing address is Planetarium, Frostburg State University, Frostburg, MD 21532 or by email at rdoyle@frostburg.edu.

By Dr. Bob Doyle