They came from outer space--and you can have one! Genuine meteorites are now on sale in the Space Weather Store.
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DECLINING CHANCE OF MAGNETIC STORMS: The CME expected on Dec. 29th either missed Earth or its impact was too weak to notice. Geomagnetic activity remains generally low with only a 20% chance of storms around the Arctic Circle during the next 24 hours.
ACTIVE SUNSPOT: New sunspot 1389 is crackling with M-class solar flares. NASA's Solar Dynamics Observatory recorded this extreme UV flash from the active region at 2151 UT on Dec. 29th:
Although the sunspot is not directly facing Earth, its flares can affect our planet. X-rays and UV radiation from yesterday's flares created waves of ionization in the upper atmosphere, altering the propagation of radio waves. The phenomenon was particularly strong over Europe where radio amateurs using low frequency receivers detected sudden ionospheric disturbances ("SIDs") above Ireland and Italy. Student groups who wish to detect solar flares in this way can ask about obtaining a SID monitor from Stanford University.
NOAA forecasters estimate a 40% chance of more M-flares during the next 24 hours. There's also a 5% chance of X-flares. Solar flare alerts: text, voice.
more images: from Michael Borman of Evansville, Indiana
MOTHER OF PEARL: As December draws to a close, the first polar stratospheric clouds (PSCs) of northern winter are forming around the Arctic Circle. Anders Gjørwad Hagen of Vinstra, Norway, photographed this specimen on Dec. 27th:
Also known as "nacreous" or "mother of pearl" clouds, icy PSCs form in the lower stratosphere when temperatures drop to around minus 85ºC. Sunlight shining through tiny ice particles ~10µm across produce the characteristic bright iridescent colors by diffraction and interference.
The display Hagen witnessed formed in the wake of "Dagmar," a storm that "hit the coast of Norway with hurricane strength on Dec. 25th and 26th," says Hagen. "Record breaking winds up to 145 mph were recorded. While people on the coast dealt with the aftermath, photo enthusiasts inland saw the effects of high altitude winds in these colorful clouds. It was a beautiful display, but not comfortable to think of all the suffering lying behind it."
more images: from Bjarki Mikkelsen of Jokkmokk Lapland, Sweden; from P-M Hedén of Tänndalen, Sweden; from Krystian Rosa of Brandbu, Norway; from Patricia Cowern of Porjus,Sweden
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 30, 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 |