SOUTHERN UTAH — The Sky Report is presented as a public service by the Stellar Vista Observatory, a nonprofit organization based in Kanab, Utah, which provides opportunities for people to observe, appreciate and comprehend our starry night sky. Additional information is available online. Send questions and comments to [email protected].
As the sky is growing dark, the planet Jupiter appears in the southeast, followed soon after by Saturn a short distance to the left. These planets are 8 degrees apart this month, but that gap will narrow dramatically in months to come until they’re almost touching (as your eye sees them) in late December. Note their separation now and remember it this fall. By the way, 8 degrees is about the width of four fingers held at arm’s length.
On the evening of Aug. 28, the Moon is less than 3 degrees below Jupiter in a nice pairing when both objects will fit within the field of view of binoculars. They appear close together in the sky but Jupiter is far beyond, of course; it’s 1,700 times farther than the Moon. If our moon were orbiting Jupiter, it would appear as small and as faint as Jupiter’s smallest moon, named Io, which you can see in any telescope. Saturn is precisely twice as distant as Jupiter, which is the main reason Saturn looks fainter. On the next evening, Aug. 29, the Moon is twice as far (6½ degrees) to the left of Saturn.
Working backward in time, on the evening of Aug. 25 the first-quarter Moon is 5½ degrees above the bright star Antares. Note Antares’s orange color; it’s a red giant star 14 billion times as distant as the Moon; that’s a ratio of 440 years to one second. Antares is the “heart of Scorpius, the Scorpion”, which is one of the oldest constellations, originating in the Middle East.
The Moon is at its first-quarter phase on Aug. 25, and the few days after are the best time to look at the Moon with a telescope, when shadows are long and the large crater Copernicus and tall, curved mountain ranges are prominent. The third planet you’ll see tonight is Mars, which rises by 11 p.m. Mars is brighter than any star and it has a noticeable orange color, so you can’t miss it. Mars is high in the south as dawn begins.
Last but not least is Venus, which rises at 3:30 a.m. and is one-third of the way up the eastern sky at 6 a.m. Venus is the brightest planet, and it now rises as early as it will all this summer. Jupiter and Saturn are in eastern Sagittarius, Mars is in Pisces and Venus is in Gemini.
Written by JOHN MOSLEY. John Mosley was program supervisor of the Griffith Observatory in Los Angeles for 27 years and is the author of “Stargazing for Beginners” and “Stargazing with Binoculars and Telescopes”. He and his wife live in St. George where he continues to stargaze from his retirement home while serving on the advisory committee for Stellar Vista Observatory.