Wednesday, January 20, 2010

The Ellensburg sky for the week of 1/23/10

Saturday: Draco Malfoy makes an appearance in all seven books of the Harry Potter series. Perhaps you’ve heard of these. But, the constellation Draco the dragon makes an appearance in the sky every night. It is a circumpolar constellation as viewed from Ellensburg meaning it never goes below the horizon. The head of the dragon is one fist held upright and at arm’s length above due north at 9 p.m. Eltanin, the brightest star in the constellation, is at one corner of the trapezoid-shaped head of Draco.

Sunday: The moon is putting the moves on seven sisters tonight. Oh, he’ll try everything. Stretch and try to put his arm around the sisters. Stop short. Use lame pick-up lines such as “Hey baby, what’s your sign?”. At 7 p.m., the open star cluster called the Pleiades, or the seven sisters, is about a half a fist to the left of the moon. As the night progresses, the Moon will get closer and closer to the seven sisters in the sky. But, alas, they never meet.

Monday: Jupiter is one fist above the southwest horizon at 6 p.m.

Tuesday: Saturn is one fist above the east horizon at 11 p.m.

Wednesday: At 11 a.m., Mars will be closer to Earth than any other day for 2010 and 2011, a miniscule 62 million miles away. Currently, the northern hemisphere of Mars is angled toward Earth. Since it is springtime on Mars, people with small to medium-sized telescopes, six inches and larger, should be able to see Mars’ northern polar icecap shrink as Martian summer arrives. It will look like a white dot at the top of Mars. (Or, the bottom of Mars if your telescope inverts the image.) Mars is three fists above due east at 8 p.m.

Thursday: Are you interested in participating in astronomy research? You don’t need to go back to school. You don’t need to spend thousands of dollars getting a fake degree from an online university. The scientists working on the High Resolution Imaging Science Experiment, or HiRISE, camera on NASA's Mars Reconnaissance Orbiter would like your input on which objects they should target for close-up pictures. While you may think the scientists are just trying to build interest in their project by having people look at pretty pictures, there is a real scientific benefit to having many eyes searching for interesting targets. There aren’t enough scientists to carefully inspect all of the low power images. And, surprisingly, computers are not nearly as effective as people in making educated judgments of images. So, go to and click on the HiWish button. You’ll be on your way to suggesting close-up targets for NASA's Mars Reconnaissance Orbiter.

Friday: Mars is at opposition tonight. No, that doesn’t mean that Mars refuses to eat his peas. (Please eat your peas, children.) Opposition means that Mars is on the opposite side of the Earth as the Sun. An object is in opposition when it is due south 12 hours after the Sun. When an object is in opposition, it is at its highest point in the sky during the darkest time of the night. A planet in opposition shines brighter and appears larger in a telescope than any other night. And since Mars is also relatively close, it is exceptionally bright tonight. Mars is six and a half fists above due south at midnight.
Mars isn’t the only “biggest of the year” celestial object in the sky tonight. The Moon is at its closest position to Earth this month, also known as perigee. Since perigee happens only three hours after the full Moon, to turns out that tonight’s is the biggest full moon of the year. The Moon will look 13% bigger and 30% brighter than the most distant full Moon of the year, in August.

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

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