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This is the Griffith Observatory Sky Report for the period between December 1 and December 31, 2021. Here are the events happening in the sky of southern California.

Mercury spends most of December close to the sun and cannot be observed. By the 31^st, the sun sets at 4:54 p.m., PST, and Mercury sets at 6:07 p.m., PST, an hour and thirteen minutes later. Do not observe any planet when it comes close to the sun, for the danger to the eyes is great.

Venus is in the evening sky. The planet is low in the southwest. On the 1^st, the sun sets at 4:44 p.m., PST, and Venus sets at 7:31 p.m., PST. On the 31^st, the sun sets at 4:54 p.m., PST, and Venus sets at 5:59 p.m., PST. Venus will then be too close to the sun to be observed until the last week of January, when it appears in the morning sky.  As Venus slowly approaches the earth, its size is 39 arcseconds in the north-south direction on the 31^st, but the crescent thins to one arcsecond.

Mars slowly rises each day in the morning sky. On December 1^st, Mars rises at 5:15 a.m., PST, and the sun rises at 6:41 a.m., PST, one hour and 26 minutes after Mars.  On December 31, Mars rises at 4:58 a.m., PST, and the sun rises at 6:59 a.m., PST, over two hours after Mars. Mars appears as a disk only four arcseconds wide and will not show any surface features through a telescope.

Jupiter is in the southwest evening sky. On the 1^st, Jupiter sets at 10:23 p.m., PST, and on the 31^st the planet sets at 8:50 p.m., PST. A telescope capable of magnification 50x will show the Red Spot, and the four bright Galilean moons may be seen moving back and forth, roughly in a line centered on Jupiter.

Saturn is also visible in the evening sky towards the southwest, west of Jupiter. On the 1^st, Saturn sets at 9:03 p.m., PST, and on the 31^st, the planet sets at 7:19 p.m., PST. The rings and Saturn’s largest moon Titan may be seen with a telescope capable of magnification 50x.

Uranus is in the constellation of Aries the Ram. Uranus sets at 4:28 a.m., PST, on the 1^st, and at 2:26 a.m., PST, on the 31^st. On the 15^th Uranus is at Right Ascension 2^h 34^m 47^s with a declination of +14° 43ʹ 47ʺ. Uranus is only 3.7 arcseconds wide, and so a telescope with a magnification of 150x is needed to show its diminutive disk.

Neptune is in the constellation Aquarius the Water Bearer. On the 1^st, Neptune sets at 12:22 a.m., PST, and on the 31^st, Neptune sets at 10:25 p.m., PST. On the 15^th Neptune is at Right Ascension 23^h 25^m 38^s with a declination of -4° 56ʹ 51ʺ. Neptune is only 2.3 arcseconds wide, and so a telescope with a magnification of 150x is needed to show the disk.

New moon occurs on the 3^rd, first quarter on the 10^th, full moon on the 18^th, and last quarter on the 26^th.

SPECIAL EVENTS

The winter solstice occurs on December 21 at 7:59 a.m., PST, as the sun reaches its southernmost point on the ecliptic, reverses its movement, and heads north.  This marks the longest night and the shortest day of the year. The day is 9 hours 53 minutes long.

The Geminid meteor shower peaks from the night of Tuesday, December 13, through the morning of Wednesday, December 14. The Geminids usually produce around 20 to 40 slow-moving meteors per hour with many bright ones. Under dark sky conditions, 150 meteors per hour are expected, but rates will be decreased by bright moonlight until 2:45 a.m., when the waxing gibbous moon sets.

Comet Leonard C/2021 A1 might be visible through binoculars or even with the unaided eye. On the 12^th, Leonard will be closest to the earth at a distance of 21,690,000 miles. By the 31^st, the comet is low in the south-southwest and sets at 6:53 p.m., PST, and the sun sets at 4:54 p.m., PST. Leonard’s predicted celestial coordinates are listed in the table below. Azimuth and elevation are at sunset. An azimuth of 270° is directly west.

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