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This is the Griffith Observatory Sky Report through January 2nd, 2020. Here’s what’s happening in the skies of southern California.
The sun reaches its southernmost point of the celestial sphere–the December solstice–at 8:19 p.m., PST, on the 21st. It is the start of winter in the Earth’s northern hemisphere and the start of summer in the southern. The winter season will end with the start of spring at the equinox on March 19th, 2020. The year’s lowest position of the sun at noon and its southernmost sunset will be celebrated at Griffith Observatory with events on our grounds with presentations that start at 11:40 a.m. and at 4:40 p.m.
The planet Venus is the brilliant, eye-catching object that gleams in the southwest sky after sunset. Its orbital motion makes Venus appear a little higher in the sky and farther from the sun each evening. As a result of its changing position, the planet’s setting time is later on successive evenings; Venus sets at 7:08 p.m. on December 19th and at 7:38 p.m. on January 2nd.
The much fainter planet Saturn is just bright enough to see against the evening twilight for a few more evenings. It can be seen to the lower right of Venus by an amount that increases on successive days. The sky darkens enough to see Saturn starting at 5:15 p.m., but Saturn will be too close to the horizon to see at that time after December 30th.
At 6:15 a.m. the sky is still dark enough to make out the planet Mars low in the southeast sky.
To find it, locate the bright orange star Antares in Scorpius the Scorpion, then just above the horizon. On December 19th, Mars appears fainter than Antares and it is located about 20 degrees to the upper right of the star. 20 degrees is roughly equal to the angle covered by your two clenched fists when placed side-by-side and viewed from arm’s length. By January 20th, the separation between Antares and Mars will shrink to only 11 degrees. Use binoculars to compare the color of Antares and Mars; the Greek name for Mars is Ares and the name Antares is Greek for “The Rival of Mars.”
On the morning of December 20th the moon is waning crescent and it is located high in the southeast sky before sunrise. The moon appears above Mars on the 22nd and it is posed between Mars and Antares on the 23rd. On the next morning the moon is to the left of Antares.
New moon on December 25th is the occasion of an annular solar eclipse visible only in the Eastern Hemisphere–but not from anywhere in the United States–between 2:29 and 8:05 Universal Time on the 26th, which is from 6:29 p.m. to 12:05 a.m., PST on the 25th. These times suggest when you might find live stream coverage of the eclipse from its centerline, which runs from Saudi Arabia, through India and Indonesia.
The moon is next seen in the evening sky on December 27th, when it appears below Venus. It appears closest to Venus on the 28th, and it is last quarter phase on the evening of January 2nd.
The International Space Station passes directly over Los Angeles on the morning of December 22nd. The ISS will cross the sky from southwest to northeast between 5:46 and 5:53 a.m., and it is at the zenith (the point directly overhead) at 5:50 a.m.
Please check our website for the holiday schedule before planning a visit to Griffith Observatory, where we provide free views of the Sun during the day and of the moon, planets, and other celestial objects at night. The next public star party on the grounds of Griffith Observatory, hosted by the Los Angeles Astronomical Society, the Sidewalk Astronomers, and the Planetary Society, will take place on Saturday, January 4th between 2:00 p.m. and 9:30 p.m.
Follow The Sky Report, All Space Considered, and Griffith Observatory on Twitter for updates on astronomy and space-related events.
From Griffith Observatory, I’m Anthony Cook, and I can be reached at griffithobserver@gmail.com.