Turn your cell phone into a field-tested satellite tracker. Works for Android and iPhone. | | | SHENZHOU 8 RETURNS TO EARTH: The unmanned Shenzhou 8 probe returned to Earth on Nov. 17th, wrapping up a three-week mission to China's Tiangong 1 space station. Shenzhou 8 spent its time in orbit practicing rendevous and docking maneuvers which are still new to China's upstart space program. Chinese authorities say the mission was a success. Tiangong 1 is still in orbit and may be seen flying through the night skies of North America this weekend. Check the Satellite Tracker or your smartphone for flyby times. LEONID METEOR SHOWER: Earth is passing through the debris field of Comet Tempel-Tuttle, parent of the annual Leonid meteor shower. Barring a direct hit by a filament of dust, which forecasters consider unlikely, this year's shower should be mild. Peak rates of 10 to 20 meteors per hour are expected on Nov. 17-18. [live counts] [meteor radar] A NASA meteor camera caught this Leonid fireball streaking across the skies of New Mexico on Nov. 17th: According to an analysis by NASA's Meteoroid Environment Office, the meteoroid hit the atmosphere traveling 72.7 km/s, a value typical of Leonids, and disintegrated about 90 km above the ground. GREAT FILAMENT: It's one of the biggest things in the entire solar system. A dark filament of magnetism measuring more than 800,000 km from end to end is sprawled diagonally across the face of the sun. NASA's Solar Dynamics Observatory took this ultraviolet picture of the structure during the late hours of Nov. 17th: If the filament becomes unstable, as solar filaments sometimes do, it could collapse and hit the stellar surface below, triggering a Hyder flare. Indeed, part of the filament already erupted on Nov. 16th, but Earth was not in the line of fire. A similar event today would likely be geoeffective because of the filament's central location on the solar disk. 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 November 18, 2011 there were 1256 potentially hazardous asteroids. Recent & Upcoming Earth-asteroid encounters: Asteroid | Date(UT) | Miss Distance | Mag. | Size | 2011 FZ2 | Nov 7 | 75.9 LD | -- | 1.6 km | 2005 YU55 | Nov 8 | 0.8 LD | 11.2 | 400 m | 2011 UT91 | Nov 15 | 9.9 LD | -- | 109 m | 1994 CK1 | Nov 16 | 68.8 LD | -- | 1.5 km | 1996 FG3 | Nov 23 | 39.5 LD | -- | 1.1 km | 2003 WM7 | Dec 9 | 47.6 LD | -- | 1.6 km | 1999 XP35 | Dec 20 | 77.5 LD | -- | 1.0 km | 2000 YA | Dec 26 | 2.9 LD | -- | 80 m | 2011 SL102 | Dec 28 | 75.9 LD | -- | 1.1 km | 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 | |