Griffith Observatory Sky Report for the week ending Wednesday, July 11, 2012

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This is the Griffith Observatory Sky Report for the period ending Wednesday, July 11, 2012. Here is what’s happening in the skies of Southern California:

Time to break out your eclipse and Venus transit solar viewers again! A new sunspot group is just large enough to see without magnification (but only with the proper protection). Known to solar astronomers as group 1515, the spots have appeared on the southwest part of the sun’s disk (to the lower right when observed at noon), and will move a little to the left day by day and if still visible, will have moved to the southeast edge by next week. These will be safely shown in detail with Griffith Observatory’s solar telescope on clear days.

After sunset, the planets Mars, Saturn, and the bright star Spica–all in Virgo the Maiden–make a notable trio. The objects are located midway up in the southwest sky as darkness falls. Saturn is less than 5 degrees above Spica, and Mars is located 22 degrees to the lower right of Saturn, moving closer to Spica and Saturn at ½˚ per day. For scale, remember that a clenched fist when viewed from arm’s length appears 10 degrees across. Saturn and its rings are among the featured objects for public viewing through Griffith Observatory’s telescopes.

The waning moon retreats from the early evening sky this week and changes its phase from gibbous to last quarter on Tuesday the 10th. Moonrise occurs an average of 28 minutes later each night, from 9:36 p.m. on the 5th to 12:19 a.m. on the 11th.

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 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, July 28.

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