Griffith Observatory Sky Report for the week ending Wednesday, April 4, 2012

This is the Griffith Observatory Sky Report for the week ending Wednesday, April 4, 2012. Here is what’s happening in the skies of Southern California:

Venus, the brightest planet, is eye-catching in the western sky after sunset and is visible until 11 p.m., when it sets in the west-northwest. On Tuesday evening, April 3, Venus will appear on the south edge of the Pleiades star cluster in Taurus the Bull, something that in recent decades has occurred every 8 years on the same date. If you want to find it in broad daylight–with binoculars or with your unaided eyes–look for it 10 degrees due south of the point directly overhead at 3:52 p.m. this week. Through a telescope, Venus is half lit on March 28, and will start to appear crescent on following days. The planet has an apparent diameter of 25 seconds.

Jupiter, the second brightest planet, is now far below Venus in the evening twilight, and sets before 10 p.m.

The waxing moon changes from crescent to first quarter on Friday March 30, and appears in gibbous phase on following nights. This will be an especially good week to follow the changing appearance of lunar features through a telescope in the early evening.

The orange planet Mars, in Leo the Lion, is well placed for observation high in the east starting at nightfall. The planet is highest in the south at 11 p.m. and sets in the west at about 5 a.m. The planet is gradually shrinking in apparent size and this week is about 13 arc-seconds across. Northern hemisphere summer on Mars begins on Monday, March 30.

The ringed planet, Saturn, outshines Virgo the Maiden’s brightest star, Spica, and glows with a golden hue. Saturn and Spica appear low in the southeast at 10 p.m., and are high in the south at about 2 a.m. Through a telescope, the northern face of Saturn’s rings appears to be tilted about 14 degrees in our direction.

Southern California residents may be able to see a rocket Launch from Vandenberg Air Force Base by looking west on Thursday afternoon, March 29, or on the back up launch date on Friday, March 30. The launch of a secret payload for the National Reconnaissance Office aboard a Delta-4 rocket (a two stage liquid fuel rocket and 2 solid boosters) is expected to take place at 3:30 p.m., P.D.T. The Spaceflight Now website has links to live video updates– I would suggest that you monitor the launch on video until the rocket clears the launch tower, then go outside to look for the distant rocket as it moves up from the western horizon, travelling south.

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 six days a week (Tuesday-Sunday) through Griffith Observatory’s telescopes before 9:30 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, March 31.

The Sky Report is updated every Wednesday. It can be read and heard on our website by following the Sky Information links. From Griffith Observatory, I’m Anthony Cook, and I can be reached at