Wednesday, April 7, 2010

The Ellensburg sky for the week of 4/10/10

Saturday: This month is Global Astronomy Month ( Astronomers around the world want to reconnect people with the night sky, thus their slogan: One People, One Sky. For a summary of Global Astronomy Month events, click on “Global Programs” at the top of the left-hand column of this website. The feature event for this week, April 11-16, is Saturn Watch. You can informally participate in Saturn Watch by watching Saturn. Imagine that! Saturn is four fists held upright and at arm’s length above the southwest horizon at 10 p.m. See if its position changes throughout the week.

Sunday: Jupiter is a half a fist below the waning crescent Moon at 6 a.m. They are low in the eastern sky, just beyond the glare of the nearly rising Sun.

Monday: Avast ye matey. Swab the poop deck. Pirates love astronomy. In fact, the term “poop” in poop deck comes from the French word for stern (poupe) which comes for the Latin word Puppis. Puppis is a constellation that represents the raised stern deck of Argo Navis, the ship used by Jason and the Argonauts in Greek mythology. Argo Nevis was an ancient constellation that is now divided between the constellations Puppis, Vela and Carina. The top of Puppis is about a fist and a half to the left of the bright star Sirius in the south-southwest sky at 9 p.m. Rho Puppis, one of the brightest stars in the constellation, is about one and a half fists above the south-southwest horizon at this time.

Tuesday: Mars is five and a half fists above the southwest horizon at 10 p.m.

Wednesday: Ours isn’t the only solar system with planets. Near the top of the constellation Cancer the crab at the extreme limit of naked eye visibility is 55 Cancri, a binary star system 41 light years from Earth and the star with the most known planets other than our Sun. There are five known planets in orbit around 55 Cancri, six fists above the southwest horizon at 10 p.m. Four of the planets are similar in size to Jupiter and one is similar in size to Neptune. It is unlikely that any of these planets have life and almost certainly not complex life as it exists on Earth. For more information about planets orbiting stars other than our Sun, called extrasolar planets, go to

Thursday: At 9 p.m., Venus is less than half a fist to the upper left of the Moon and Mercury is about a finger-width below the Moon. They are all about a half a fist above the west horizon.

Friday: Remember the old saying: April showers bring… meteors. The Lyrid meteor shower is typically active from tonight to April 27. The meteors appear to come from a point to the right of the bright bluish star Vega in the constellation Lyra the lyre. This point is about three fists above the east-northeast horizon at midnight tonight and close to straight over head near dawn. The best time to look is just before dawn since that is when the radiant, or point from which the meteors appear to come, is high in the sky. Also, there is no Moon visible at this time to obscure dimmer meteors. As your Mother might say, dress warm and sit in a comfortable chair for maximum enjoyment. Meteors are tiny rocks that hit the Earth and burn up in the atmosphere. This is typically one of the least interesting major meteor showers of the year with about 10-20 meteors per hour. However, it is also one of the most unpredictable. As recently as 1982, there were 90 meteors visible during a single hour. In addition, the Lyrid meteor shower has historical interest because it was one of the first ones observed. Chinese records say “stars fell like rain” in the shower of 687 B.C.

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

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