Astronomy Info & Events: December

Moon Phases

December 3: Full Moon (Full Cold Moon)

December 10: Last Quarter Moon

December 17: New Moon

December 26: First Quarter Moon

Special Events

December 3: Occultation of Aldebaran (dawn for western North America). Largest Full Moon of 2017!

December 11: Royal Astronomical Society of Canada (Edmonton Centre) meeting from 7:30 p.m. – 9:30 p.m. in the IMAX Theatre at TELUS World of Science. Main presentation: AlbertaSAT. Free to attend.

December 13 & 14: Geminid meteor shower peaks.

December 14: See Jupiter below the waning crescent Moon in the predawn southeastern sky.

December 21: Winter solstice occurs at 9:29 a.m. MST

December 30: Aldebaran re-emerges from behind the Moon at 7:17 p.m. MST (occultation)

Visible Planets

Mercury becomes visible low along the southeastern horizon from December 18 into the early part of January 2018. 

Venus is not visible this month as it will be too close to the setting Sun, leading to its superior conjunction (point on the other side of the Sun as seen from Earth) on January 9. 

Mars is located above the southeastern horizon before sunrise this month and is seen as a faint reddish looking object. In early December look for Mars near the bright star Spica in the constellation of Virgo, the maiden. On December 21, Mars moves from the constellation of Virgo into the constellation of Libra, the scales. Look for Mars just below the slim waning crescent Moon during the dawn hours of December 13.

Jupiter is found low in the southeastern sky before sunrise this month. During the predawn hours of December 14 the slim waning crescent Moon can be seen just above Jupiter. Jupiter is currently located in the constellation of Libra, the scales, and is found near the star Zubenelgenubi.

Saturn is not visible this month as it appears too close to the Sun. Saturn will reappear in our predawn southeastern sky in January 2018.