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The Sky This Week, 2013 October 8 - 15

Back from the furlough and there's plenty to see.

Jupiter, cylindrical projection map based on observations between 2013 SEP 18 and OCT 03

The Moon waxes in the evening sky this week, starting off as a slender crescent in the southwest twilight sky and ending the week as a generous gibbous climbing through the faint stars of autumn. First Quarter occurs on the 11th at 7:02 pm Eastern Daylight Time. This is yet another great week to get to know our nearest neighbor in space, and to sweeten the deal the evening of the 12th is "International Observe the Moon Night". The goal of this collaborative effort of scientists, educators, and amateur astronomers is to promote awareness of our natural satellite and to appreciate its beauty and the inspiration that it has provided people over the millennia. Whether you look at her with your naked eye, through binoculars, or with a telescope, there is something for everyone to relate to. The stark beauty of her airless landscapes and the alien forms of countless impact craters bear mute testimony to the processes that built the planets from a primordial cloud of leftover star-stuff. Visit the program’s website to find Moon observing parties in your area. Here in Washington the Smithsonian Institution and Northern Virginia Astronomy Club will host an event at Sky Meadows State Park near Paris, Virginia, beginning at 6:00 pm. Look for a lovely triangle made up of the crescent Moon, bright Venus, and the ruddy star Antares during evening twilight on the 8th.

Early in the week the evening sky remains dark enough for exploration of the star clouds of the Milky Way. As twilight ends the most prominent of these arc overhead from the northeast to the southwest. Binoculars are very well-suited for drawing attention to many interesting star clouds and asterisms. One of my favorite binocular objects lies about one-third of the way along an imaginary line drawn from Altair, southernmost star in the Summer Triangle, toward Vega, the brightest of the trio. Here you’ll find a group of half a dozen stars in a perfectly straight line with another three forming a "hook" halfway along the line’s length. Formally catalogued as Collinder 399, this asterism is popularly called "The Coathanger" and is easy to spot from suburban skies. Later in the evening, look to the northeast sky between the "W"-shaped constellation of Cassiopeia and the bright star Mirfak in Perseus. Here you’ll find two bright star clusters embedded in the Milky Way. They form a beautiful pair in binoculars and are especially spectacular when seen from a dark-sky site.

Dazzling Venus is still very prominent in the evening twilight sky. She is now gradually beginning to pull ahead of the Sun, and during the course of the month she becomes easier to see after the end of evening twilight. This week she gets a visit from the waxing crescent Moon on the evening of the 8th. If you have binoculars watch her close in on the ruddy star Antares as the twilight sky darkens. She will pass just over a degree north of the star next week.

Jupiter now rises before midnight, but the best time to observe him is still just before sunrise. However, if you have a telescope and a clear eastern horizon, try giving him a gander at 1:00 am EDT on the morning of the 12th. Even though he’ll only be 12 degrees above the horizon in the Washington area, three of his four Galilean moons will be casting their shadows across his face. This is an exceedingly rare event that will repeat in 2014 and 2015, but after that we won’t see another such "triple play" until 2032! On the 9th our friends in the southern hemisphere may get a chance to see the next spacecraft bound for Old Jove. At 3:21 pm EDT the Juno orbiter will pass just 350 miles above South Africa to gain a "gravity assist" from the Earth and set its course for Old Jove. Juno should arrive at Jupiter on July 4, 2016 for a one year mission to the planet and its moons.

Ruddy Mars is now well up in the east at the onset of morning twilight. I had my first glimpse of the red planet last week as I spent my furlough time exploring the pre-dawn sky. Mars still has a long way to go before it becomes an item for intense telescopic scrutiny, but it was nice to see his cheery glow in the telescope nonetheless. This week you can watch him close in on the bright star Regulus in the gathering morning twilight. On the morning of the 15th he passes just under a degree north of the star.

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