Astronomy Info & Events: December

Moon Phases

December 7: New Moon

December 15: First Quarter Moon

December 22: Full Moon (the Full Cold Moon or the Full Long Nights Moon)

December 29: Last Quarter Moon

Special Events

International Space Station (ISS) Observable Passes

ISS passes are visible during the early evening hours early in the month and then shifting to the morning pre-dawn hours during the latter part of the month. Check out the website http://www.heavens-above.com or by using satellite tracking smart phone apps like Sputnik to find out the exact times when the ISS will be visible from your location. The ISS will be seen as a bright moving point of light, moving in an arc from the west to the east during its visible passes.

December 1: Venus will be at its brightest (in the dawn eastern sky)

December 4: Comet Wirtanen (Comet 46/P) starts to be seen in the northern sky and will be located in the constellation of Taurus, the bull. It could become a naked eye comet with a possible brightness of magnitude 3!

December 6: Neptune will be seen approximately 20 arc minutes from Mars!

December 8: Look for Saturn near the very slim waxing crescent Moon (early evening).

December 10: Royal Astronomical Society of Canada (RASC) Edmonton Centre meeting 7:30 p.m. – 9:30 p.m. in the new Zeidler Dome at TELUS World of Science. Free to attend. See http://www.edmontonrasc.com for more details. 

December 13/14: Geminid meteor shower peaks over the evening of December 13 through till the morning hours of December 14. Up to 120 meteors per hour have been recorded in past showers. Great dark skies late in the evening after moonset.

December 18: Comet 46P/Wirtanen closest distance to the Earth of 11.6 million km!

December 21: Winter solstice occurs at precisely 3:23 p.m. MST

December 22/23: Ursid meteor shower peaks (only 5 to 10 meteors seen per hour - minor shower)

Visible Planets

Mercury is visible before sunrise with some difficulty very low above the southeastern horizon from December 3 to December 20. On December 5 look for the elusive Mercury just below the slim waning crescent Moon before sunrise.

Venus shines brilliantly low in the east-southeastern sky before sunrise. During the predawn hours of December 3 look for a nice conjunction of the waning crescent Moon with Venus.  

Mars is seen in the southern sky after sunset, gaining elevation in the southern sky from night to night, during the month. Mars moves from the constellation of Aquarius, the water bearer, into the constellation of Pisces, the fish, on December 21. On December 14 look for Mars just above the first quarter Moon.

Jupiter emerges out of the rising Sun's glow low in the southeastern sky in the final week or so of December. On December 22, Mercury and Jupiter will be very near one another in the dawn sky but this conjunction may be rather difficult to see as they are both in the glow of the rising Sun.

Saturn is situated very low along the southwestern horizon early in the month and will be exceedingly difficult to see in the glow of the setting Sun. It then disappears from our evening sky, heading for its conjunction with the Sun on January 2, 2019.