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This is the Griffith Observatory Sky Report for the week ending Wednesday, February 20, 2013. Here is what’s happening in the skies of Southern California:
A 160 foot-wide Asteroid, designated 2012 DA14, will make a close but harmless pass by earth on Friday morning, February 15th. The asteroid will travel inside the ring of geostationary satellites when it is closest to our planet at 11:24 a.m., P.S.T. At that moment, 2012 DA14 will be 17,200 miles above Indonesia. Because its south-to-north motion relative to earth is nearly perpendicular to the equator and to the ring of geostationary satellites orbiting above the equator, it is unlikely that the asteroid will come nearer than 1,200 miles to any satellite. People located across much of the Eastern Hemisphere will have a chance to see 2012 DA14 as a sensibly moving spot, shining at magnitude 7.2, but it will be a challenging object to find through hand-held binoculars. Video of the asteroid will be shown (weather permitting) on the NASA Marshall Spaceflight Center’s Ustream site (http://www.ustream.tv/channel/nasa-msfc) between 3:00 p.m. and 6:00 p.m., P.S.T. By the time night falls in California, 2012 DA14 will have faded from visibility to all but large telescopes. People in Europe, the Middle East, Asia, Africa, and the eastern Pacific, the zone where the closest approach is visible, can generate finder maps showing the apparent track among the stars for each particular observing location with the special 2012 DA14 link on the Heavens-Above satellite-tracking page. Because of the asteroid’s nearness, you must specify your observing location on the Heavens Above website (www.heavens-above.com) in order to produce accurate predictions.
The moon brightens in the evening sky, as its waxing phase grows from crescent to first-quarter phase on Sunday the 17th, then gibbous for the remainder of the week. It is visible longer night after night and the time of moonset advances from 9:20 p.m. to 2:49 a.m. between the 13th and the 20th.
The planet Mercury, appearing like a bright star, is easy to see starting about 30 minutes after sunset. It is then located about 12 degrees above the west-southwest horizon. For comparison, 10 degrees is about the same angular size that your clenched fist covers when viewed at arm’s length.
Jupiter continues to be the brightest planet of the evening. Located in Taurus the Bull, Jupiter appears nearly overhead in the southern sky when darkness falls. The planet sets in the west-northwest by 1:30 a.m. The first-quarter moon appears next to Jupiter on Sunday, the 17th. Jupiter is a featured object through Griffith Observatory’s public telescopes.
Saturn, in Libra the Scales, appears as a bright golden star in the southeastern sky after it rises at 11:20 p.m. The ringed planet is best seen at 4:45 a.m., when it crosses the meridian midway between the southern horizon and overhead.
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 Wednesday-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 between 2:00 p.m. and 9:30 p.m. on Saturday, March 16th.
From Griffith Observatory, I’m Anthony Cook and I can be reached at griffithobserver@gmail.com.