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MORE SIGNALS FROM PHOBOS-GRUNT: After two weeks of silence, Russia's malfunctioning Phobos-Grunt spacecraft has resumed contact with Earth. An ESA antenna in Perth Australia received signals and telemetry from Phobos-Grunt on Nov. 23rd and 24th. Mission controllers still aren't sure why the spacecraft failed to fire its engines toward Mars, leaving the probe stuk in Earth orbit, but these signas raise hopes of saving the mission. News reports: #1, #2
THANKS FOR THE SKY SHOW: Officially, the odds of a geomagnetic storm on Nov. 24th were small, but Steve Milner of Ft. St. John, British Columbia, decided to wake up early and look anyway. This is how his Thanksgiving day began:
"I was checking Spaceweather last night and saw that the chances for auroras at my latitude was only about 4%," he says. "When I got up this morning I was surprised to see that 4% is enough. This picture was taken at around 5:30 am."
Auroras have been flickering around the Arctic Circle for several days. These displays are not caused by major solar activity. Instead, they are prompted by small magnetic fluctuations in the solar wind. The interplanetary magnetic field (IMF) near Earth tips south, partially cancelling Earth's north-pointing magnetic field. Solar wind pours in, oh so briefly, to excite the Northern Lights. Aurora alerts: text, phone.
more images: from Borkur Hrolfsson of Reykjavik, Iceland; from Eric Rock of Churchill, Manitoba; from Pavel Kantsurov of Norilsk, Russia
SOLAR ERUPTION: On Nov. 23rd, a magnetic filament wrapping around the sun's NW limb rose up and erupted. Click on the arrow to play the movie recorded by NASA's Solar Dynamics Observatory:
The eruption hurled a cloud of plasma (a "CME") into space but not toward Earth. Because of the blast site's high-northern location on the sun, the cloud flew up and out of the plane of the solar system; no planets will be affected.
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. An animated map created by graphic artist Larry Koehn shows the eclipse unfolding across the southern end of our planet:
Maximum coverage occurs about 100 miles off the coast of Antarctica where the sun will appear to be a slender 9% crescent. Observers in the eclipse zone should be alert for crescent-shaped shadows and sunbeams. The sun-dappled ground beneath leafy trees is a good place to look. Of course that won't work in Antarctica where trees are scarce. Observers there should use safe solar filters to witness the crescent sun itself.
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 24, 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 |