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This is the Griffith Observatory Sky Report through September 30, 2015. Here’s what’s happening in the skies of southern California.
A total eclipse of the harvest full moon occurs on Sunday, September 27. The eclipse is already underway when the moon rises above the eastern horizon at about 6:39 p.m., PDT, during sunset at Los Angeles. The exact time of sunset and moonrise, however, depends on how flat and unobstructed your local horizon is. The eclipse becomes total at 7:11 p.m. Twilight ends at 8:06 p.m., and totality ends at 8:23 p.m. The moon moves completely out of the well defined part of Earth’s shadow, the umbra, at 9:27 p.m. Shading from the fuzzy outer shadow of the earth will probably be visible until about 10:00 p.m. The calculated end of the penumbral eclipse is at 10:22 p.m., but because the remaining penumbral shading is too subtle to see, the moon will appear like a regular full moon from about 10:00 p.m. on. The moon is at perigee, at the closest point of its elliptical orbit around Earth at 6:52 p.m., and as a result, the totally eclipsed moon will be nearly as large as it can ever appear during an eclipse, and will appear 13 percent larger than it did at last April’s eclipse. You can watch the eclipse by unaided eye, although binoculars will help you see the beautiful hues of copper and red during totality, the result of sunlight bent and filtered into Earth’s shadow by our atmosphere. This total lunar eclipse is the last of the rare series of four consecutive total lunar eclipses, or tetrad, that started in April 2014. The next total lunar eclipse visible from Los Angeles will occur in 2018, and the next tetrad will start in 2032. More information about Sunday’s eclipse is available on our eclipse web page.
The planet Saturn, in the constellation Libra the Scales, is the brightest object in the southwest sky after sunset. Saturn sets in the west-southwest at about 9:30 p.m.
Early risers can get the best view the planets Venus, Mars and Jupiter at 5:45 a.m. Venus is the highest of the three, and is the brightest object in the sky, after the moon, located 26 degrees high in the east. Jupiter is the second brightest and lowest of the three planets, a little farther left and only a third as high as Venus. Between Venus and Jupiter are two objects of about equal brightness, the glittering white star Regulus of Leo the Lion, and the steady glow of the red planet Mars. Mars is a little less than one degree to the upper left of Regulus on the 24th, and on following mornings appears farther and lower to the left of Regulus. By the morning of the 30th, Mars appears 3½ degrees from Regulus.
The International Space Station will pass directly over Los Angeles at dawn on the 27th. Appearing only a little fainter than Venus, the ISS will cross the sky from northwest to southeast between 5:42 and 5:49 a.m. The space station is 75 degrees high in the northeast sky at 5:45 a.m. Two of the orbiting laboratory’s six residents, American Scott Kelly and Russian Mikhail Kornienko, are now just past the halfway point of their record-long 342 day tour of duty onboard the ISS.
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 the 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, October 17.
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From Griffith Observatory, I’m Anthony Cook and I can be reached at griffithobserver@gmail.com