Griffith Observatory Sky Report for the week ending Wednesday, December 17, 2014

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This is the Griffith Observatory Sky Report for the week ending Wednesday, December 17, 2014. Here is what’s happening in the skies of southern California:

The planet Mars, in Capricornus the Sea Goat, is the only bright planet easily visible in the early part of the evening. At nightfall, Mars looks like an orange, first magnitude star, about 20 degrees above the southwest horizon.

At 10:00 p.m., not long after rising, brilliant planet Jupiter is noticeable above the east-northeast horizon. Jupiter, in Leo the Lion, crosses the meridian, 71 degrees high in the south, at about 4:00 a.m. The planet can still be seen high in the southwest at sunrise. On the morning of Tuesday, December 16, observers equipped with telescopes will be able to see Jupiter’s moon Europa occult (move in front of) another bright Jovian moon, Io. This occultation will last from 2:36 a.m. to 3:04 a.m., PST. At the occultation’s maximum, at 2:55 a.m., the disk of Europa will cover 65-percent of Io’s disk, an interesting sight through a large telescope at high magnification. Our moon will appear close to Jupiter on the mornings of the 11th and 12th.

The moon’s phase wanes from gibbous to last quarter on the 14th. On following mornings the moon is a crescent as it approaches new moon on the 21st.

The year’s strongest meteor shower, the Geminids, should reach its maximum on the night of December 13/14. Although the shower can produce up to 120 meteors per hour in ideal conditions, without moonlight or light pollution, the rising of the last quarter moon at 11:36 p.m. may reduce the number somewhat, and observing from urban or suburban locations will dramatically lower the numbers of visible meteors. Many Geminid meteors are bright, however, and can be fun to watch between 10:00 p.m. and dawn no matter where you are.

The launch of a Defense Department intelligence satellite on Thursday, December 11, may be visible from southern California, weather permitting. The ascending Atlas V rocket with its classified payload, called NROL-35, should take off from Vandenberg Air Force Base as early as 7:17 p.m., PST. Vandenberg is on the California Coast to the west of Los Angeles, and the rocket may be visible in the sky as it arcs to the south. Live launch coverage is to be provided on the United Launch Alliance website.

Another interesting launch to follow should be that of the cargo supply mission (called CRS-5) to the International Space Station on December 16. As the first stage booster of the SpaceX Falcon 9 falls back to earth after performing its role in the launch, an attempt will be made to land it upright and gently on a special barge in the Atlantic Ocean. This is a test by SpaceX to lower launch costs by making re-usable rockets. The launch is scheduled to take place on Tuesday at 11:31 p.m., PST. Coverage should be provided on the NASA-TV and SpaceX websites.

Experienced telescope observers in the Los Angeles area may want to watch a 9th magnitude star in Gemini the Twins to see if it winks out because of the passage of a faint asteroid, 125 Liberatrix. The star could disappear for up to four seconds depending on where in the asteroid’s shadow you might be. The occultation should take place at 5:31 a.m., PST on Thursday, December 11. All the necessary charts, maps, and updates needed to watch this occultation are on Steve Preston’s asteroid occultation website.

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 our 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 27.

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From Griffith Observatory, I’m Anthony Cook and I can be reached at griffithobserver@gmail.com.