Wednesday, April 9, 2014
The Ellensburg sky for the week of 4/12/14
Saturday: The nighttime stars take little more than an instant to rise. The Moon takers about two minutes to rise. That’s absolutely speedy compared to the constellation Virgo, which takes four hours to rise. The first star in Virgo rises at 4:30 in the afternoon today. Spica, the brightest star in the constellation, rises at 7:30. By 9 p.m., Spica is one fist held upright ant at arm’s length above the southeast horizon. Mars is a fist above Spica.
Sunday: Tonight at 10 p.m., listen to an Eminem song. Next, eat some M & M candies. Finally, look three fists above the southeast horizon to see the Moon and Mars side by side for the entire night. That’s right. Watch the sky’s own M and M while eating M & Ms while listening to Eminem. You’ll have a great time or my name’s not (what?). My name’s not (who?). My name’s not… Slim Shady.
Monday: Last night, did you lose yourself in the music, the moment watching the Moon and Mars? Well, tonight’s even better. Tonight there will be a total lunar eclipse. Total lunar eclipses are not as noticeable as total solar eclipses because light still reaches the Moon even when it is completely blocked by the earth. That is because the Earth’s atmosphere acts like a lens and bends rays of light that would normally miss the moon towards the moon. That doesn’t mean the moon looks the same during a total lunar eclipse as it does during a normal full moon.
Sunlight is white. White light is the sum of all of the colors in the visible spectrum (red, orange, yellow, green, blue, indigo and violet). Our atmosphere scatters the blue component of the Sun’s white light. That is why our sky is blue. (If our atmosphere consisted of different gasses, we would likely have a different colored sky.) When the Sun or moon is near the horizon, the light passes through a lot of the atmosphere meaning a lot of the blue light is scattered and the Sun or moon looks redder than when it is high in the sky. During a total lunar eclipse, sunlight passes through a large slice of the Earth’s atmosphere. The remaining light that reaches the moon is reddish. Thus, the moon looks red during a total lunar eclipse.
From our perspective in central Washington, the moon will begin the partial eclipse stage at 10:59 p.m. The moon will slowly move into the Earth’s shadow and get dark from left to right. At 12:08 a.m., the moon will be fully eclipsed. The total eclipse lasts until 1:23 a.m. The moon will be moving out of the earth’s darkest shadow or umbra until 2:32 a.m. After that, the moon will look white, just like a normal full moon. Thus, during the entire eclipse, the moon looks white, then black, then red all over. For more information, go to NASA Science News at http://goo.gl/q19W5E.
Tuesday: The Lyrid meteor shower peaks next week. But there will be increased meteor activity for the next two weeks in the vicinity of the constellation Lyre. 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 and close to straight overhead near dawn.
Wednesday: Saturn is about a finger width to the upper left of the Moon in the southeast sky at 10 p.m. By sunrise tomorrow at 6 a.m., they are about twice as far apart and are in the southwest sky. The main east to west motion of objects in the sky is due to the rotation of the Earth. The actual motion of objects really far away such as stars, and even planets, does not affect what we can observe with the naked eye over one night. But the Moon is so close to us, its actual motion can be observed over a few hours. Its actual is best observed on a night like tonight when there is another bright object next to the Moon throughout the night.
Thursday: Venus is one fist above the east-southeast horizon at 6 a.m.
Friday: Jupiter is nearly five fists above the west-southwest 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 https://nightsky.jpl.nasa.gov/planner.cfm.