Thursday, August 9, 2012

The Ellensburg sky for the week of 8/11/12

Saturday: The Perseid meteor shower hits its peak tonight and early tomorrow morning. The meteors appear to come from a point just below the W of the constellation Cassiopeia. This point is about two and a half fists held upright and at arm’s length above the northeast horizon at 11 p.m. By dawn, this point is about seven fists above the northeast horizon. With dark skies, you can see up to 100 meteors per hour in the late night and early morning hours all week. Unfortunately, the early morning waning crescent moon will obscure all but the brightest fireballs. As your Mother might say, dress warm and sit in a comfortable chair for maximum enjoyment. These meteors are sand to pea-sized bits of rock that fell off of Comet Swift-Tuttle. They are traveling about 40 miles per second as they collide with the Earth and burn up in the atmosphere. For more tips about the Perseid meteor shower, go to http://goo.gl/CC63c.

Sunday: The Moon is about halfway between Venus and Jupiter this morning. The brighter Venus is a fist and a half to the lower left and Jupiter is a fist to the upper right of the Moon.

Monday: Have there been a lot of crimes in our part of the galaxy? Perhaps because there have been Solar System line-ups two days in a row. At 9:30 p.m., the star Spica is a half a fist above the west-southwest horizon. Mars is about two fingers above Spica and Saturn is a half a fist above Spica. All three objects have a similar apparent brightness making it more difficult to identify the perpetrator.

Tuesday: Many big city dwellers never see the milky white, nearly continuous band of stars known as the Milky Way. As cities grow and add more lights, it has become harder to see the bulk of the Milky Way galaxy, our home in the universe. But, there are two easy ways to see the Milky Way. The first way is to look in the mirror. You are part of the Milky Way. The second way is to look from due north through the point straight overhead (called the zenith) to due south from 10:30 p.m. to 1 a.m. for the next two weeks. This is the time of year when the Milky Way is highest in the sky and away from the city lights on the horizon.

Wednesday: Mercury is about a half a fist above the horizon at 5:30 a.m. Even though Mercury is our second closest planetary neighbor, its proximity to the Sun makes it difficult to see most of the time. Luckily, it is a half a fist to the lower left of the Moon this morning giving us another marker to help us find it. It is also in a ling line with Venus and Jupiter.

Thursday: You think the Ellensburg wind is bad. Some of the Jovian planets have winds of over 1000 miles per hour. Jupiter and Saturn have belts of rapidly moving clouds that can be observed with back yard telescopes. To learn more about windy worlds, go to http://goo.gl/GLWAi.

Friday: Deneb is about seven fists above the east horizon at 10 p.m. When you look at Deneb, you are seeing light that left Deneb about 1,800 years ago.

The positional information in this column about stars and planets is typically accurate for the entire week.

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