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This is the Griffith Observatory Sky Report through January 24, 2018. Here’s what’s happening in the skies of southern California.
Look for the slender crescent moon just above the west-southwest horizon on the 17th, at 5:30 p.m. On following evenings, the moon will appear higher and stay visible for a longer time as its phase waxes. It becomes first quarter on the 24th, and afterwards it is gibbous until the full moon and total lunar eclipse on the 31st. The eclipse, which will happen in the hours before sunrise, will be featured in next week’s Sky Report. The time of moonset changes from 5:57 p.m. on the 17th to 11:40 p.m. on the 23rd. By the weekend, the rugged face of the moon will be featured through the public telescopes at Griffith Observatory.
Bright objects form a line across the southeast sky shortly after dawn starts. The brightest of these is the planet Jupiter, in the constellation Libra the Scales. Jupiter rises at 2:00 a.m. At 6:30 a.m., about half an hour before sunrise, it is 38 degrees above the south-southeastern horizon.
The orange planet Mars, also in Libra, rises half an hour after Jupiter. At dawn, Mars is easy to see about six degrees to the lower left of Jupiter. For comparison, remember that your clenched fist appears ten degrees wide when held at arm’s length. Extending the line made by Jupiter and Mars halfway toward the horizon brings you to the orange star Antares, the brightest star of the constellation Scorpius the Scorpion. Antares and Mars appear similar in color, and the star’s ancient Greek name means “the rival of Mars.”
Midway between Antares and the horizon is the golden-hued planet Saturn, in the constellation Sagittarius the Archer. The dazzling rings of Saturn are visible only through telescopes. Saturn and its rings will be observable in the evening sky starting in the summer.
Elusive planet Mercury – usually difficult to observe because of its proximity to the sun – can be seen until the 23rd, to the lower left of Saturn and very close to the horizon at about 6:30 a.m. Mercury’s rapid orbital motion will draw it deeper into the sun’s glare, into which it will vanish by the 23rd. We will next see Mercury, in the evening sky, in March.
The International Space Station passes over Los Angeles on the evening of Tuesday the 23rd. The ISS will cross the southern sky as it moves up from the southwest horizon until it reaches Earth’s shadow, near the constellation Orion in the southeast between 6:32 and 6:35 p.m. The space station will then outshine everything in the sky except the moon when it reaches its highest point, 48 degrees above the southeast horizon, less than 30 seconds before it is engulfed in shadow and fades quickly from view.
Free views of the Sun during the day and of the moon and other interesting celestial objects at night are available to the public in clear weather through Griffith Observatory’s telescopes from Tuesday through Sunday, before 9:30 p.m. Check our website for the schedule. The next free 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 27th.
Follow the Sky Report on Twitter for updates of astronomy and space-related events.
From Griffith Observatory, I’m Anthony Cook, and I can be reached at griffithobserver@gmail.com.