COMET SNOWSTORM ENGULFS HARTLEY 2: At a press conference today at NASA headquarters, researchers released beautiful new images of an unprecedented snowstorm raging around Comet Hartley 2. Get the full story from Science@NASA.
ANOTHER DOOMED COMET: For the second time in less than a week, a comet is diving toward the sun. Polish comet hunter Michal Kusiak found it yesterday in coronagraph images from the Solar and Heliospheric Observatory:
Click here for an UPDATED movie
It's no coincidence that this comet is following the same path as its predecessor on Nov. 14th. They are both fragments of a single giant comet that broke apart about 2000 years ago. Astronomers call them "Kruetz sungrazers" after the 19th century German researcher, Heinrich Kreutz, who studied them in detail.
"November is one of the best months to discover Kreutz comets," notes Kusiak. "It's because the field of view of the SOHO coronagraph covers a larger-than-usual portion of the Kreutz track. December, May, and June are good, too."
With SOHO staring at just the right patch of sky, more sungrazers are probably in the offing. First, however, this one has a date with destiny, and it probably won't survive. Solar heating is expected to obliterate the icy sundiver later today or tomorrow. Stay tuned for movies of the death plunge.
AURORA WATCH: Earth is exiting a solar wind stream that sparked bright auroras around the Arctic Circle on Nov. 14th-16th. Øystein Lunde Ingvaldsen sends this picture from Bø in Vesterålen, Norway:
"The auroras were dancing over my head and at my feet," says Ingvaldsen, who caught the lights reflecting in the cool water's edge using his Nikon D700. "It was a wonderful display."
According to NOAA, the chance of more geomagnetic activity during the next 24 hours has dropped to 15%, a result of declining solar wind speed. The odds are better, however, in the gallery.
November 2010 Aurora Gallery
[previous Novembers: 2009, 2008, 2007, 2006, 2004, 2003, 2002, 2001, 2000]
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, 2010 there were 1164 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 |