Turn your cell phone into a field-tested satellite tracker. Works for Android and iPhone. | | | ANTARCTIC SOLAR ECLIPSE: On Nov. 25th the Moon will pass in front of the sun, slightly off-center, producing a partial solar eclipse visible from Antarctica, Tasmania, and parts of South Africa and New Zealand. Maximum coverage occurs about 100 miles off the coast of Antarctica where the sun will appear to be a slender 9% crescent. [animated map] LAST SUNSET: As northern winter approaches, darkness is enveloping the countries of the Arctic. In fact, today in Tromsø, Norway, night fell less than ten minutes after sunrise. Fredrik Broms photographed the sun during its few minutes above the horizon: "After a long slow dawn, the sun rose for one of the last times of the year today," says Broms. "My girlfriend and I went out to say a last goodbye to the sun and minutes after sunrise the dusk began. Here in Tromsø the polar night period lasts from November 25 - January 17, but because of the surrounding mountains, the sun is due to set on November 22. Together with several other people who attended to pay a last farewell to the Sun today, we say thank you for 2011, sun. We'll see you again in January." ACTIVE SUNSPOT: A new sunspot has emerged over the sun's NW limb and it could bring an uptick in solar activity. On Nov. 18th, the active region hurled a bright CME toward Venus, and on Nov. 19th it produced the following eruption, recorded by the Solar and Heliospheric Observatory: So far, Earth has been unaffected by the action of this sunspot group, but this could change as the region turns toward our planet in the days ahead. Stay tuned. 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 20, 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 | |