LISTEN to this week’s Sky Report
This is the Griffith Observatory Sky Report for the week ending Wednesday, February 15, 2012. Here is what’s happening in the skies of Southern California:
Planets Venus and Jupiter, in the western sky, should catch your attention shortly after sunset. Jupiter, the higher and fainter planet, is gradually drawing closer to Venus in the sky. The planets will reach their closest proximity (their conjunction) next month. Venus sets at 8:50 p.m., preceding Jupiter by two hours.
Venus will reach conjunction with the planet Uranus on Thursday, February 9. Beginning at about 6:30 p.m., the sky should be dark enough to find 6th magnitude Uranus only 19 arcminutes (or 60-percent of an apparent moon diameter) to the south of Venus with the aid of binoculars or a telescope. Uranus is to the left and slightly lower than Venus with respect to the horizon. Uranus appears star like in binoculars, but a telescope at 100 power will show both planets together. Venus will appear in gibbous phase – 9,000 times brighter and five times larger than pale green Uranus.
Telescope users will want to note that a shadow transit of Jupiter’s largest moon, Ganymede, will be visible on Wednesday night, February 8, between 6:21 p.m. and 8:08 p.m., P.S.T. Io will cast its smaller shadow on Jupiter between 6:45 p.m. and 8:54 p.m., P.S.T. on Sunday the 12th.
The waning moon changes from gibbous to last quarter phase on the morning of Valentine’s Day, and will appear crescent on following mornings. The time of moonrise advances from 6:48 p.m. on the 8th to 1:29 a.m. on the 15th.
The moon will cover (or occult) a star known as 87 Leonis on Friday morning, February 10. A telescope will reveal the sudden re-appearance of the 4.8 magnitude star from behind the dark south western limb of the moon at 3:08 a.m., P.S.T. as seen from Los Angeles, or within a few minutes of that time anywhere in southern California.
Orange planet Mars, in Leo the Lion, is conspicuous in the east by 8:30 p.m. With its close approach to earth less than a month away, its apparent telescopic diameter of over 13 arcseconds is almost as large at it will appear at any time over then next two years. The best time to observe with a telescope is when the planet is high above the southern horizon, which this week occurs between midnight and 4:00 a.m. Mars is farthest from the sun on Wednesday, February 15, and west-coat observers using telescopes should be on the lookout for bright clouds clinging to the large volcanoes of the Tharsis region at prime time this week. The moon appears near Mars on Friday morning the 10th.
Planet Saturn, not far from Virgo the Maiden’s brightest star, Spica, is visible in the southeast before midnight and is high in the south at dawn. Its rings are spectacular in almost any telescope. The moon passes near Saturn on Monday morning, the 13th.
With the moon out of the sky in the early evening by the weekend, the International Dark Sky Association is sponsoring a worldwide activity to increase awareness of the night sky’s greatest enemy, artificial light pollution. The event, called globe at night, invites you to make a measurement of the faintest star visible to your eye near the constellation Orion from wherever your are, between the nights of February 12 through the 20th. Instructions and an App for making and automatically reporting your observations can be found at the event’s homepage, www.globeatnight.org.
This week’s best appearance of the International Space Station from Los Angeles happens on Sunday night, February 12. The ISS moves across the sky from southwest to northeast, between Venus and Jupiter, between 6:36 and 6:41 p.m., P.S.T. The ISS reaches its apex of 66 degrees in the northwest at 6:40 p.m., then fades into earth’s shadow when it reaches the bowl of the Big Dipper.
Free public viewing of the sun during the day and of the moon, planets and other celestial objects at night, is available in clear weather, Wednesday through Sunday, through Griffith Observatory’s telescopes before 9:45 p.m. Check our website for our schedule. The next public star party of the Los Angeles Astronomical Society and the Sidewalk Astronomers is scheduled for Saturday, February 25.
The Sky Report is updated every Wednesday. It may be read and heard on our website, and is found by following the Sky Information links. From Griffith Observatory, I’m Anthony Cook, and I can be reached at griffithobserver@gmail.com.