Where's Saturn? Is that a UFO--or the ISS? What's the name of that star? Get the answers from mySKY--a fun new astronomy helper from Meade. | | | MOON & MARS: When the sun sets tonight, go outside and look west. See the Moon? The red "star" right beside it is the planet Mars. The two are gathered beautifully close together in the heart of the constellation Gemini: sky map. MOONDUST IN THE WIND: Unlike Earth, the Moon has no magnetic field to ward off charged particles from the Sun. Solar wind blows directly onto the lunar surface. Researchers have long suspected that electrons in the solar wind become embedded in moondust, causing the dust to "charge up" and giving the Moon a very bad case of static cling. (continued below) Image credit: J. Halekas, G. Delory (U.C. Berkeley), B. Farrell, T. Stubbs (GSFC) Strange things can happen when moondust gathers charge. For one, the dust might rise up and, propelled by electrostatic repulsion, rush in a diaphanous wind across the lunar surface. Imagine, dust storms on an airless world with no weather! But it could be even stranger than that. NASA researchers have discovered that moondust peppered with solar wind electrons gain not a negative but a positive charge. This unexpected and counterintuitive reaction makes it hard to predict what is really happening to dust on moon. Get the full story from Science@NASA. 3D MOON OF MARS: Grab your 3D glasses. Two weeks ago, NASA's Mars Reconnaisance Orbiter (MRO) targeted martian moon Phobos and took a pair of high-resolution pictures. Mission scientists have combined them to make a startling red-blue anaglyph. Glasses on? Behold. The 2D view is nearly as good: Long ago, something struck Phobos and almost shattered the tiny moon. The scar of that impact, 9km-wide Stickney crater, is located at the top of the image. Color filters in MRO's camera reveal a blue splash of material around Stickney's rim. What is it? No one knows. Equally striking are Phobos' many long grooves and crater chains. Although these seem to radiate from Stickney, recent studies show that most are not related to the crater. Instead they come from the planet below; when asteroids hit Mars, debris flies up and scores Phobos. The grooves seem to emerge from Stickney only because the crater faces Mars. Finally, note the bright features lining inner slopes of Stickney. These are thought to be landslides--on a moon where the pull of gravity is only 0.001 g! Visit the Mars Reconnaissance Orbiter home page for more information, March 2008 Aurora Gallery [Aurora Alerts] [Night-sky Cameras] |