The Ellensburg sky for the week of 1/18/14

Saturday: Who can forget that memorable song by Three Dog Constellations Night, “The sky is black. The stars are white. Together we learn to find the light.” Well, maybe it didn’t go like that. This is good because not all stars are white. Most stars are too dim to notice a color. But, the stars in the constellation Orion provide a noticeable contrast. Betelgeuse, five fists held upright and at arm’s length above the south horizon at 10:30 p.m. is a red giant. Rigel, the bright star about two fists to the lower right of Betelgeuse, is a blue giant.

By the way, the three dog constellations are Canis Major, the greater dog; Canis Minor, the lesser dog; and Canes Venatici, the hunting dogs. Canis Major contains Sirius, the brightest star in the nighttime sky.

Sunday: Just back from a long engagement in the evening sky, Venus makes its return to the morning sky. Venus is one fist above the southeast horizon at 7 a.m. At this same time, Saturn is two and a half fists above the south horizon

Monday: Are you looking for a vacation spot close by? One that is not to hot and not too cold. One that is “just right”. One year ago, astronomers discovered that the star Tau Ceti, one of our closest neighbor at 12 light years away, may have five planets. One of those planets orbiting the Sun-like star is in the so-called Goldilocks Zone where the temperature is just right for having liquid water. You’ll want to do some research before you travel there. Tau Ceti is two and a half fists above the south-southwest horizon at 7 p.m. For more information about the discovery, go to http://goo.gl/xcv0dl.

Tuesday: You never see a giraffe on the ground in Ellensburg. But you can look for one every night in the sky. The constellation Camelopardalis the giraffe is circumpolar from Ellensburg’s latitude of 47 degrees north meaning it is always above the horizon. Don’t expect to be overwhelmed by the appearance of the stars in Camelopardalis. The brightest star in the constellation appears only about half as bright as the dimmest star in the Big Dipper. However, the actual luminosities of the three brightest stars in Camelopardalis are very high, each at least 3,000 times more luminous than the Sun. Alpha Camelopardalis, a mind boggling 600,000 times more luminous than the Sun, is seven fists above due north at 10 p.m.

Wednesday: The moon rises just after midnight tonight in the east-southeast sky. By 12:30 a.m., the bright star Spica will be visible about a pinky width to the lower right of the moon and Mars will be a half a fist to the upper left. But as the night moves on, you’ll see the moon moving eastward, away from Spica and Mars. This is evidence that the moon is closer to the Earth than either Mars or Spica. The closer an object is to the Earth, the more its actually motion affects where we see it in the sky. Stars are so far away that nearly 100% of the motion we observe is because the earth is moving. It would take a few nights of careful observation to see that Mars has moved with respect to the stars. Of course, you know that the moon is closer than the planets and the planets are closer than the nighttime stars. (Don’t you?) But it is helpful to have easily observable evidence.

Thursday: Are you interested in participating in astronomy research? You don’t need to go back to school. You don’t need to spend thousands of dollars getting a fake degree from an online university. The scientists working on the High Resolution Imaging Science Experiment, or HiRISE, camera on NASA's Mars Reconnaissance Orbiter would like your input on which objects they should target for close-up pictures. While you may think the scientists are just trying to build interest in their project by having people look at pretty pictures, there is a real scientific benefit to having many eyes searching for interesting targets. There aren’t enough scientists to carefully inspect all of the low power images. And, surprisingly, computers are not nearly as effective as people in making educated judgments of images. So, go to http://www.uahirise.org/ and click on the HiWish button. You’ll be on your way to suggesting close-up targets for NASA's Mars Reconnaissance Orbiter.

Friday: Jupiter is six and a half fists above the south horizon at 11 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.