Turn your cell phone into a field-tested satellite tracker. Works for Android and iPhone. | | | ERUPTING FILAMENT: Today, with little warning, a magnetic filament rapidly erupted on the sun. Between 10:30 and 11:30 UT, observers in Europe watched tendrils of hot plasma rocket away from the sun's NW limb. Debris from the explosion is not expected to hit Earth. Images: #1, #2, #3. SUPER-SIZED ECLIPSE: On Saturday morning, Dec. 10th, sky watchers in the western United States and Canada will witness a total lunar eclipse swollen to super-sized proportions by the Moon illusion. Get the full story from Science@NASA. NORTHERN LIGHTS: Auroras are flickering around the Arctic Circle in response to a minor solar wind stream, which is buffeting Earth's magnetic field. Ronn Murray sends this Dec. 3rd snapshot from Murphy Dome in Fairbanks, Alaska: "I photographed my friend Marketa enjoying the view during a very beautful spell of auroras," says Murray. The lights were caused not by a strong magnetic storm but rather by small magnetic fluctuations in the solar wind. During the early hours of Dec. 3rd, the IMF tipped south, partially cancelling Earth's north-pointing magnetic field; solar wind poured through the breach to fuel the display. NOAA forecasters estimate a 14% chance of similar events tonight. Aurora alerts: text, phone. more images: from Casey Thompson of Fairbanks, AK LOCAL STARSCAPE: With no flares of significance in days, the sun is strangely quiet. Nevertheless, the view remains dynamic. Rogerio Marcon of Campinas, Brasil, took this picture of the local starscape on Dec. 2nd: Using a telescope tuned to the red glow of solar hydrogen, Marco captured 20 billion sq. km of seething plasma and magnetic filaments; also included in the field is the dark core of sunspot 1364 (lower right). It doesn't look very quiet. NOAA forecasters estimate a 30% chance of M-class solar flares in the next 24 hours. Solar flare alerts: text, phone. Potentially Hazardous Asteroids ( PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time. On December 3, 2011 there were 1272 potentially hazardous asteroids. Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach. | The official U.S. government space weather bureau | | The first place to look for information about sundogs, pillars, rainbows and related phenomena. | | Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever. | | 3D views of the sun from NASA's Solar and Terrestrial Relations Observatory | | Realtime and archival images of the Sun from SOHO. | | from the NOAA Space Environment Center | | the underlying science of space weather | |