Wednesday, February 11, 2009

The Ellensburg sky for the week of 2/14/09

Saturday: 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 stares 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 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 held upright and at arm’s length 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.

Sunday: Comet Lulin, discovered in July 2007, is just above the bright star Spica for the next three mornings. Grab your binoculars and look two and a half fists above the southwest horizon at 6 a.m. Spica is the brightest star in that region of the sky. Comet Lulin will be an elongated smudge just above it.

Monday: Saturn is almost two fists above the east horizon at 9 p.m.

Tuesday: The bright star Antares is about a finger’s width to the left of the Moon at 6:30 a.m. They are due south at this time.

Wednesday: “Happy Birthday to you. Happy Birthday to you. Happy Birthday dear Pluto. Happy Birthday to you.” Clyde Tombaugh discovered Pluto, the solar system object formerly known as a planet, on this day in 1930.

Thursday: The calendar may say February, but the late night sky is starting to say “summer triangle”. Vega, the brightest star in the summer triangle rises at 10:30 p.m. By midnight, it is a little less than one fist above the northeast horizon. The Summer Triangle is a set of three stars that is visible high throughout most of the night in the summer sky.

Friday: Three planets crowd the morning twilight sky. From lower left to upper right, Mars, Jupiter and Mercury are less than a half a fist above the east-southeast horizon, just ahead of the rising Sun. You may need binoculars to pick them out of the glare.

The positional information in this column about stars and any planet except Mercury is accurate for the entire week.


Megan Murray said...

Why is the information about Mercury not accurate?

Bruce Palmquist said...

Position information for Mercury is only accurate for a few days at a time. Because Mercury is the closest planet to the Sun, it moves through the sky much faster than the other planets. If I say Venus, Mars, Jupiter, or Saturn (the other naked eye planets) will be x fists above the south horizon on Sunday, they'll remain pretty close to that location throughout the week. But not Mercury. It will move a noticable amount in just a few days.