Wednesday, December 10, 2014
The Ellensburg sky for the week of 12/13/14
Saturday: The Geminid meteor shower peaks for the next two nights. Meteor showers are named after the constellation from which the meteors appear to originate. These meteors appear to come from a point in Gemini the twins. This point is about three fists held upright and at arm’s length above the east-northeast horizon at 9 p.m. tonight. You can follow this point throughout the night, as it will remain near the bright star Castor, the right hand star of the “twin” stars Pollux and Castor. This shower is typically one of the best ones of the year producing bright, medium speed meteors with up to 80 meteors per hour near the peak. This year, the nearly full moon will obscure some of the dimmer meteors. For more information about the Geminid shower, go to http://earthsky.org/space/everything-you-need-to-know-geminid-meteor-shower.
Sunday: You’ve heard the term “a pinch to grow an inch.” Well, Jupiter’s extremely strong gravitational field “pinches” Jupiter so much that it causes Jupiter to shrink by about an inch a year. Look for the svelte Jupiter two fists above due east at 11:07 p.m.
Monday: Mars is about one fist above the southwest horizon at 6 p.m.
Tuesday: Of course you can see the stars at night. If you know where to look, you can also see a few of the brighter stars during the day. This morning, you can use the moon to help you see Spica in a pair of binoculars. First, find the moon two fists above the southwest horizon at 11 a.m. Move your binoculars so the moon is on the far right edge of your field of view. Spica should be near the middle of the field of view for most binoculars.
Wednesday: Today is Saturnalia, an ancient Roman festival in honor of their god Saturn, the god of agriculture and time. The holiday featured a break from work and school, a public banquet, and private gift giving. Some of these customs influenced the secular aspects of Christmas celebrations. Celebrate Saturnalia at 7 a.m. by viewing the planet Saturn, one fist above due southeast. Seeing the real Saturn on the morning of December 17? As Leonard said on The Big Bang Theory, “It’s a Saturnalia miracle.”
Thursday: On these cold mornings, it is difficult to get going. You just want to plop into a chair and sit still. But, are you really sitting still? You’re moving at about 700 miles per hour due to the rotation of the Earth on its axis and 66,000 miles per hour due to the revolution of the Earth around the Sun. If that’s not enough, the entire solar system is orbiting the center of the galaxy at a whopping 480,000 miles per hour! So while you may be sitting still with respect to your living room (and all of the over achievers in your house), you are NOT sitting still with respect to the center of the galaxy. For more information about this concept, go to http://goo.gl/lPVPS. Before you barf from all of that motion, go outside at 7 a.m. and observe Saturn, about two fists below the moon in the southeast sky. Because of Saturn’s rapid rotation, only 10.5 hours, it appears visible flattened.
Friday: Not only can you can see some of the “nighttime” stars during the day, you can also see bright planets. Once again, the moon will be your guide. First, find the moon two fists above the southwest horizon at noon. Move your binoculars so the moon is on the right side of your field of view. Saturn will be a little more than a moon diameter to the lower left of the moon. Now that you have found it in binoculars, try to spot it with your naked eye about a pinky-width to the lower left of the moon.
The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to http://nightsky.jpl.nasa.gov/planner.cfm.