Wednesday, February 10, 2016

The Ellensburg WA sky for the week of 2/13/16

Saturday: Hopefully you’ve spent a few pre-dawn mornings over the last month looking at the five naked eye planets. That fun is not going to last because soon there will be just three visible planets. However, if you have binoculars, you should be able to find the asteroid Vesta in the post-dusk evening sky. Vesta is the brightest and second largest asteroid. In 2011, Vesta became the first asteroid orbited by a human-made satellite when NASA’s Dawn spacecraft arrived.  Make Dawn the first asteroid observed by looking in the southwest sky at 7 p.m. First find the fairly bright star Deneb Kaitos less than one fist held upright and at arm’s length above the southwest horizon. Next, find the Great Square of Pegasus two and a half fists above the west horizon. Draw an imaginary line up from Deneb Kaitos and draw another imaginary line to the left from the left-most star in the Great Square. Aim your binoculars where those two lines cross. Your eyes might first be attracted to a bluish dot in the vicinity. That’s the planet Uranus. When you place Uranus in the right-hand side of your field of view, Vesta will be on the left-hand side. It will not stand out from the rest of the stars. The only way you’ll know it is Vesta is if you check again over the next few nights. All of the points of light in your field of view will remain in place except Vesta. It will move to the upper left of your field of view. Uranus will also move up but not nearly as much. For more information, go to

Sunday: Today: According to Greek mythology, the beautiful princess Andromeda was chained to a rock next to the ocean. Cetus the sea monster was about to devour her in order to punish her family. It seemed that all was lost. But, along came the great warrior Perseus, fresh off his defeat of the evil Gorgon, Medusa. The only similarity between Andromeda and Medusa was that Andromeda caused people to stand still and stare at her beauty while Medusa turned people to stone because of her ugliness. (And, you thought you looked bad in the morning.) Even though Perseus’ standing as the son of King Zeus and the slayer of Medusa was probably enough to win Andromeda under normal circumstances, Andromeda’s impending death-by-sea-monster was not a normal circumstance. So, Perseus drove his sword into the sea monsters neck and killed it. In a little known addendum to the story, Perseus carved “Percy (heart symbol) Andi” in the rock, thus originating the use of the heart symbol as a substitute for the word “love”.
You can find these lovers in the sky this Valentine’s Day. Just remember it is rude to stare – and you never know when you might turn to stone. First, find the Great Square of Pegasus at 7 p.m. between one and a half and three and a half fists above the west horizon. The lowest star in Andromeda is the top star in the square. This represents Andromeda’s head. Perseus is at her feet, nearly straight overhead. Mirphak, the brightest star in Perseus, is about eight fists above the west horizon. Perseus’ body is represented by the line of stars to the left and right of Mirphak.

Monday: You think wintertime weather is bad in Ellensburg. Astronomers have discovered storms and earth-sized clouds on a brown dwarf. These are cool, small stars that are not massive enough to fuse hydrogen atoms and fuse hydrogen. In fact, they are more similar to gas giant planets such as Jupiter that to the Sun. In this context, the discovery of storms similar to the giant Red Spot on Jupiter makes sense. For more information, go to

Tuesday: As mentioned earlier, the Naked Planet Morning Peep Show will be ending soon. (That sounded more innocent when I said it in my head.) This morning at 6:30, Jupiter is one and a half fists above the west horizon. Mars is two and a half fists above the south horizon. Saturn is to the left of Mars, two fists above the south horizon. Venus, the brightest planet, and Mercury are less that a half a fist above the southeast horizon, with Mercury being to the lower left of Venus.

Wednesday: The bright star Arcturus is nearly two fists above the east horizon at 11 p.m.

Thursday: “Happy Birthday to you. Happy Birthday to you. Happy Birthday dear Pluto. Happy Birthday to you.” On this day in 1930, Clyde Tombaugh discovered Pluto, at that time classified as the ninth planet. However, as astronomers started discovering a lot of similar objects in that part of the solar system, they realized that had a classification crisis on their hands. Should everything in this region of the solar system be named a planet? Eventually the International Astronomical Union (IAU) reclassified Pluto and all future Pluto-like objects as dwarf planets.
All noteworthy birthdays need a party so the CWU Museum of Culture and Environment is hosting an 86th birthday party for Pluto at 5:30 pm. Members of the CWU physics department will talk about Pluto and recent Solar System discoveries. The museum is in Dean Hall, found at K-8 on the campus map: Parking is free after 4:30.

Friday: Jupiter is nearly two fists above the east horizon at 9 p.m.

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

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