This is the Griffith Observatory Sky Report through December 2, 2015. Here’s what’s happening in the skies of southern California.
On the crisp, clear nights of late November, a bright, glittering star shines above the east-southeast horizon before 10:00 p.m. This is the brightest nighttime star, Sirius, of the constellation Canis Major, the Big Dog. In mythology, Canis Major is the largest of the hunting dogs of Orion the Hunter. The constellation of Orion is above Sirius when the star rises, and can be recognized because of the belt of Orion, a striking group of three stars, equally spaced from one another in a slightly crooked line. Between November 25 and December 2, the rising time of Sirius moves earlier by four minutes per day because of Earth’s orbit around the sun. The time changes from 9:04 p.m. to 8:36 p.m. during this period. Because of Earth’s rotation, Sirius appears to arc upwards and to the right, reaching due south and its highest point in the sky 5½ hours later. Orion’s belt is then found to the upper right of Sirius.
The moon changes from full on November 25th to waning crescent on following nights until it reaches last quarter on December 2nd. Its rising time over this period advances from 5:04 p.m. to 11:36 p.m. At 3:00 a.m. on Thursday morning, the 26th, the full moon will appear very close to the bright orange star Aldebaran of the constellation Taurus the Bull. Across the northern portion of the western half of the United States and western Canada, the moon will pass in front of, or occult, Aldebaran.
The brilliant planet Jupiter, appearing more than twice as bright as Sirius, rises in the east just before 1:00 a.m. Jupiter is still easy to see 30 minutes before sunrise, when it is 60 degrees high in the east-southeast. Bands of clouds can be seen through a telescope aimed at Jupiter, and Jupiter’s four largest moons can be seen in steadily held binoculars.
The brightest planet, Venus outshines Jupiter by a factor of two and rises in above the east-southeast horizon within a few minutes of 3:10 a.m. Thirty minutes before sunrise, Venus is easy to find in the southeast sky, half as high as Jupiter. Venus currently displays a gibbous phase through a telescope.
Between Venus and Jupiter, look for the orange glow of the planet Mars. Mars is currently relatively distant compared to how it will be positioned in late May next year, but through fine telescopes and steady air, West Coast observers should be able to pick out the white north polar cap of Mars and the planet’s most recognizable of its large dark markings, the triangular Syrtis Major.
Comet Catalina (C/2013 US10) can be seen at 5:15 a.m., just before the start of dawn. The newest observations indicate that it currently appears at magnitude 6.0, meaning that it should be visible in binoculars in clear skies. In the sky, the comet lies along a line running from Mars to Jupiter and nearly to the horizon, in the constellation Virgo the Maiden. Sky and Telescope magazine has a webpage devoted to observing comet Catalina.
Two fine passes of the International Space Station can be seen from Los Angeles on coming evenings. On Friday the 26th, the ISS will appear above the northwest horizon at 7:13 p.m. It moves higher but vanishes quickly into Earth’s shadow at 7:16 p.m. when the brilliant satellite is 64 degrees high in the northwest. On Sunday the 29th, the ISS crosses the sky from southwest to the north-northeast between 6:09 and 6:15 p.m., and appears highest at 6:12 p.m. when it is 48 degrees above the northwest horizon.
Free views of the sun during the day and of the moon, planets, and other 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 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, December 19.
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From Griffith Observatory, I’m Anthony Cook and I can be reached at firstname.lastname@example.org.