Wednesday, January 18, 2012

The Ellensburg Sky for the week of 1/21/12

Saturday: Draco Malfoy makes an appearance in all seven books of the Harry Potter series. Perhaps you’ve heard of these. But, the constellation Draco the dragon makes an appearance in the sky every night. It is a circumpolar constellation as viewed from Ellensburg meaning it never goes below the horizon. The head of the dragon is one fist held upright and at arm’s length above due north at 9 p.m. Eltanin, the brightest star in the constellation, is at one corner of the trapezoid-shaped head of Draco.

Sunday: Tonight’s Moon is new. Don’t bother looking for it. The new moon is the phase where the Moon is directly between the Earth and the Sun. Hence the side of the Moon facing Earth is not receiving any sunlight and cannot be seen.

Monday: Jupiter is four and a half fists above the southwest horizon at 8 p.m.

Tuesday: How many of you live a sedentary lifestyle? Well, get off the couch, go outside and look at the sky. Mars, which is one fist above the east horizon at 10 p.m., should remind you of the sedentary lifestyle tonight because it is stationary. Being stationary does not mean hovering in the sky all night in the exact same location like that spaceship your weird uncle supposedly saw. A stationary planet still rises and sets with the other objects in the sky because this motion is due to the Earth’s rotation. Outer planets such as Mars typically move slightly westward each night with respect to the background stars. As they are in the process of being passed up by Earth, they appear to slow down and stop their westward motion for a night. Tonight is that night. For an effective demonstration of this, go to

Wednesday: Venus is about a fist to the left of the newly crescent Moon low in the western sky at 6 p.m.

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 and click on the HiWish button. You’ll be on your way to suggesting close-up targets for NASA's Mars Reconnaissance Orbiter.

Friday: What is the number one threat to the peaceful use of space? Missiles from rogue nations? Nope. Aliens? You wish they’d take you away after seeing the preview of Men in Black 3. It is space junk. Hundreds of thousands of pieces of space junk orbit the earth, most of it in the main human-made satellite region. The US Department of Defense is tracking over 21,000 objects greater than four inches across to assess the danger they pose. Go to to find out what large pieces of that space junk is visible any night. You may select your location from a map, from a list, or enter it manually. The bright object three and a half fists above the south-southwest horizon at 6:30 a.m. is definitely not space junk. It is Saturn.

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

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