This is the Griffith Observatory Sky Report for the week ending Wednesday, September 3, 2014. Here is what’s happening in the skies of southern California:
Golden planet Saturn and orange planet Mars appear close together, low in the southwest sky during evening twilight. Mars appears nearly 4 degrees below and slightly to the left of Saturn at the start of the week. Mars will drift farther to the left of Saturn as the week progresses. Both planets set by about 10:30 p.m.
The waxing crescent moon returns to the evening sky on Wednesday the 27th. On that evening, the sky will be dark enough to see the moon by 7:55 p.m., half an hour after sunset. The moon will then be about 6 degrees above the western horizon. For comparison, remember that your clenched fist appears about 10 degrees across when held at arm’s length. The moon passes Virgo the Maiden’s bright star Spica on the 29th, makes a tight triangle with Mars and Saturn on the 31st, and is high above the bright star Antares of Scorpius the Scorpion on September 1.
Distant planet Neptune reaches opposition (the point in the sky opposite to the sun) in Aquarius the Water Carrier on Thursday night the 28th. This is when the planet is visible all night, and is at its closest to us–28.97 times as far as the sun, or 2.62 billion miles, the distance covered by light in four hours and one minute. Neptune requires at least a small telescope to be observed. Its apparent diameter of 2.4 arc-seconds is about one-tenth as wide as Mars appears at its largest. Finder charts to identify Neptune are available at the Sky and Telescope site and at The Sky Live web page.
Brilliant planet Jupiter and the brightest planet, Venus, are best seen in the dawn, shortly before 6 a.m. The separation between the planets grows from 9½ degrees on August 27 to 16½ degrees on September 3.
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, August 30.
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From Griffith Observatory, I’m Anthony Cook and I can be reached at firstname.lastname@example.org.