Wednesday, May 2, 2012

The Ellensburg Sky for the week of 5/5/12

It’s a plane. It’s a bird. No, it’s Supermoon! The biggest and brightest full moon this year, 14% bigger and 30% brighter! This will lead to very high tides! And an overuse of exclamation points! The Moon is full on Saturday night meaning the Earth, Moon, and Sun are in line with each other. That means the Moon and Sun are both stretching the Earth along the same axis causing the ocean water in line with the Sun and Moon to be pulled upward. In addition, the moon is at perigee Saturday night. Peri- means close and –gee refers to the Earth so this is the day of the month when the moon is closest to the Earth. Tonight is the closest the full moon gets all year, which accentuates the upward pull on the water and makes the tides really high. For more information about Supermoon, go to

Saturday: The Eta Aquarid meteor shower peaks tonight and tomorrow morning. But since this meteor shower has a fairly broad peak range, there will be many more meteors than in the typical pre-dawn sky throughout the month. Meteor showers are named after the constellation from which the meteors appear to originate. The meteors appear to come from a point in the constellation Aquarius near the star Eta. This point is about one fist held upright and at arm’s length above the east horizon at 4 a.m. Although the full moon will light the sky, you could be rewarded with a few bright, fast meteors. The Eta Aquarid meteors slam into the Earth at about 40 miles per second. They often leave a long trail. The Eta Aquarid meteors are small rocks that have broken off Halley’s Comet. For more information about the Eta Aquarids, go to

Sunday: Mother’s Day is a week away. What are you going to get her? Get her a Gem(ma). The star Gemma, also known as Alphekka, is the brightest star in the constellation Corona Borealis, the Northern Crown. Gemma, Latin for jewel is the central gemstone for the crown. It is four fists above due east at 10 p.m.

Monday: Antares is about a half a fist to the lower left of the Moon at 4 a.m.

Tuesday: Venus, the brightest point of light in the sky, is one and a half fists above the west horizon at 10 p.m. Owing to their own motion and the Earth’s motion, planets appear to move with respect to the background stars. Tonight, Venus is about a pinky thickness to the left of the star at the tip of one horn on Taurus the bull. Since the Arabs that named many of the stars were quite sensible, they called the star El Nath, meaning “the butting one”. Watch Venus for the next few nights as it moves away from El Nath.

Wednesday: Sirius, the brightest star in the night sky, is less than a half a fist above the southwest horizon at 9 p.m. Soon it will be lost in the glare of the Sun.

Thursday: Mars is four fists above the south-southwest horizon at 10 p.m.

Friday: This weekend, celebrate Mother’s Day with the big mom of the sky, Virgo. Ancient Greeks and Romans associated this portion of the sky with their own goddess of the harvest, either Demeter (Greeks) or Ceres (Roman). Demeter was the mother of Persephone and Ceres was the mother of Proserpina. According to myth, each of these daughters was abducted causing their mothers great grief. The first star in Virgo rises in the afternoon. Spica, the brightest star in the constellation rises at 6:30 and is two and a half fists above the southeast horizon at 10 p.m. Saturn is about a half a fist to the upper left of it.

The positional information in this column about stars and planets is typically accurate for the entire week. This column is also available online at

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