Wednesday, March 25, 2009

The Ellensburg sky for the week of 3/28/09

Saturday: You probably didn’t know this but several British New Wave bands were really into astronomy. Take the band “Dead or Alive” (please). The original lyrics to their song “You Spin my Round (Like a Record) were thought to be: “ You spin me right round, baby, right round, like the Whirlpool Galaxy, right round, round, round.” (Well, that’s what I thought them to be.) The Whirlpool Galaxy was the first galaxy observed to have a spiral shape. Since then, astronomers have discovered many galaxies, including our own Milky Way Galaxy, have a spiral shape. Go to http://astronomy2009.nasa.gov/observe.htm for more information about the Whirlpool Galaxy. Go to your small telescope to find the Whirlpool Galaxy in the night sky. It is in the constellation Canes Venatici, the hunting dogs. At 10 p.m., find Alkaid, the end star of the Big Dipper handle, in the northeast sky. The Whirlpool Galaxy is two fingers to the upper right of Alkaid.

Sunday: The moon is spending a fun-filled Monday morning and afternoon with seven sisters. (Don’t tell Mrs. Moon.) At 9 p.m. tonight, the open star cluster called the Pleiades, or the seven sisters, is a half a fist to the upper left of the moon. During the night and into tomorrow, the moon will move to being right next to the Pleiades. By tomorrow night, the Pleiades will be below the moon. Expect the moon to sleep on the couch tomorrow night.

Monday: April’s “Hot Topic” for the International Year of Astronomy is galaxies and the distant universe. When Galileo turned his telescope to the seemingly continuous band of light in the sky, he discovered it consisted of countless faint stars. This extended our celestial neighborhood from a few thousand stars to millions of stars. This neighborhood configuration lasted until the 1920’s when Edwin Hubble discovered that there are other galaxies with millions, or even billions, of stars just like our own galaxy. Go to http://astronomy2009.nasa.gov/topics.htm for more information about the April “Hot Topic”.

Tuesday: Jupiter is about a fist held upright and at arm’s length above the southeast horizon at 6 a.m.

Wednesday: After a long journey through space, there is nothing will quench your thirst better than a few drops of refreshing Mars water. Wait! Is this an April Fool’s Day joke? No. After analyzing photos taken by the Mars Phoenix Lander, a group of astronomers discovered drops of very salty liquid water on one of the Lander’s legs. Because Mars is so cold and has such a thin atmosphere, astronomers thought water could exist in solid and vapor form only. But, temperature fluctuations in the Mars polar region and the saltiness of the soil where Phoenix landed probably created a pocket of water too salty to freeze. Salt water freezes at a lower temperature than fresh water, no matter what planet it is found on. Scientists think that ice was melted by the Lander’s exhaust and splashed on the leg at impact. Furthermore, some of the muddy, salty water drops seem to have grown by absorbing water vapor from the atmosphere. This is similar to how water droplets form and grow on the outside of a cool glass. You’ll need binoculars to see Mars this morning. It is less than a half a fist above the east-southeast horizon at 6:15. As the weeks go by, Mars will move higher and high in the morning sky. For more information about liquid water on Mars, go to http://www.skyandtelescope.com/news/41728642.html.

Thursday: Tonight’s first quarter moon is in the constellation Gemini the twins.

Friday: Saturn is four fists above the southeast horizon at 9 p.m. Saturn’s largest moon, Titan, is visible with binoculars to the right of Saturn. Astronomers studying Titan’s spin assumed that its rotation rate (spin on its axis) was the same as its rate of revolution around Saturn. This is the case for our moon. But, data from the Cassini mission shows that Titan’s rotation seems to be increasing. Some astronomers hypothesize that Titan’s high winds are contributing to the increase.

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

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