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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 343.7 km/sec
density: 2.7 protons/cm3
explanation | more data
Updated: Today at 2344 UT
X-ray Solar Flares
6-hr max: B3
1816 UT Dec15
24-hr: C3
0000 UT Dec15
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 15 Dec 11
None of these sunspots poses a threat for strong flares. Credit: SDO/HMI
Sunspot number: 65
What is the sunspot number?
Updated 14 Dec 2011

Spotless Days
Current Stretch: 0 days
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 821 days
Typical Solar Min: 486 days

Updated 14 Dec 2011


The Radio Sun
10.7 cm flux: 132 sfu
explanation | more data
Updated 14 Dec 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Planetary K-index
Now: Kp= 0 quiet
24-hr max: Kp= 0
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 2.7 nT
Bz: 0.7 nT south
explanation | more data
Updated: Today at 2345 UT
Coronal Holes: 15 Dec 11
There are no large coronal holes on the Earthside of the sun. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2011 Dec 15 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
01 %
01 %
CLASS X
01 %
01 %
Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at: 2011 Dec 15 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
05 %
05 %
MINOR
01 %
01 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
15 %
MINOR
10 %
10 %
SEVERE
05 %
05 %
 
Thursday, Dec. 15, 2011
What's up in space
 

Turn your cell phone into a field-tested satellite tracker. Works for Android and iPhone.

 
Satellite flybys

COMET LOVEJOY UPDATE: Matthew Knight of the Lowell Observatory and JHU-APL reports: "As of 16:30 UT on Dec. 15th, Comet Lovejoy has reached magnitude -3, possibly brighter. It is starting to saturate SOHO images even with narrow filters and shorter than normal exposure times." The comet is now brighter than Jupiter, but not quite as bright as Venus. If these developments continue apace, Comet Lovejoy could become visible to the naked eye in broad daylight before the end of Dec. 15th. See the news item below for further discussion of this possibility.

BIG COMET PLUNGES TOWARD THE SUN: Comet Lovejoy (C/2011 W3) is diving into the sun and furiously vaporizing as it approaches the stellar surface. The Solar and Heliospheric Observatory (SOHO) is recording the kamikaze plunge:


SOHO Coronagraph: movie, latest image

"This is, without any doubt, the brightest sungrazing comet that SOHO has ever seen," says Karl Battams of the Naval Research Lab in Washington DC.

The comet's nucleus, thought to be twice as wide as a football field, will skim approximately 140,000 km (1.2 solar radii) above the solar surface on Dec. 15/16. At such close range, solar heating will almost certainly destroy the comet's icy core, creating a cloud of vapor and comet dust that will reflect lots of sunlight.

"If Comet Lovejoy gets as bright as magnitude -4 or -5, there is a tiny but non-zero chance that it could become visible in the sky next to the sun," says Battams.

Indeed, something similar happened to Comet McNaught in January 2007 when it was visible in broad daylight: gallery. Standing in the shadow of a tall building to block the sun allowed the comet to be seen in blue sky nearby.

"Comet Lovejoy will be reaching perihelion (closest approach to the sun) right around sunset on Dec. 15th for people in the US East, Central, Mountain, and Pacific time zones," continues Battams. "Be alert for the comet to the left of the sun at that time." Caution: Do not look at or near the sun through unfiltered optics; focused sunlight can seriously damage your eyes.

Discovered on Dec. 2nd by amateur astronomer Terry Lovejoy of Australia, the comet is an unusually large member of the Kreutz family. Kreutz sungrazers are fragments of a single giant comet (probably the Great Comet of 1106) that broke apart back in the 12th century. SOHO sees one plunging into the sun every few days, but most are small, no more than 10 meters wide. Comet Lovejoy is at least ten times larger than usual.

Got pictures of Comet Lovejoy? Submit them here.

COMET LOVEJOY HAS A COMPANION: "Comet Lovejoy has a friend!" notes Karl Battams in his blog. "Look for it in the upper-half of this animation moving perfectly in step with Lovejoy. It's another Kreutz-group comet. This is not surprising. SOHO's Kreutz-group comets are very 'clumpy,' for want of a better word. We frequently see them arrive in pairs or sometimes trios, and the big bright ones in particular will often have a little companion comet."

GEMINID FIREBALLS: On the night of Dec. 13/14, NASA's All-Sky Meteor Network recorded 35 fireballs streaking over the southern USA. Twenty-two of them had remarkably similar orbits:

The clustered green orbits match the trajectory of near-Earth asteroid 3200 Phaethon, source of the annual Geminid meteor shower. The Geminids have been active this week as Earth passes through the asteroid's mysterious debris stream. The other, non-Geminid orbits correspond to random meteoroids. Not belonging to any organized debris stream, random meteoroids litter the inner solar system and produce a daily drizzle of "sporadic" fireballs.

NASA's fireball network, which connects multiple cameras in New Mexico, Alabama, Georgia and Tennessee, is a "smart" system. It rapidly and autonomously calculates meteoroid orbits from the fireballs it records. Another orbit diagram is just hours away; stay tuned.

more Geminids: from Fredrik Broms of Kvaløya, Norway; from Paul Martin of Omagh, Co Tyrone N.Ireland; from Salvador Aguirre of Hermosillo, Sonora, Mexico; from Mike Hankey of Freeland, Maryland; from Ugur Ikizler of Kirazlı - Uludag - Bursa / Turkey

CURIOSITY AND THE SOLAR STORM: Last month, a massive solar storm launched itself toward Mars just as NASA's new rover, Curiosity, was blasting off from Cape Canaveral in the same direction. Researchers say it was a welcome coincidence. For the first time in Mars-rover history, Curiosity is equipped to study solar storms, and it will be monitoring space weather all the way to the Red Planet. [full story]


Dec. 10th Total Lunar Eclipse Gallery

  Near Earth Asteroids
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 15, 2011 there were 1272 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
2003 WM7
Dec 9
47.6 LD
--
1.6 km
2000 YA
Dec 26
2.9 LD
--
80 m
2011 SL102
Dec 28
75.9 LD
--
1.0 km
2011 WS95
Dec 28
7.2 LD
--
49 m
1991 VK
Jan 25
25.3 LD
--
1.9 km
433 Eros
Jan 31
69.5 LD
--
8.5 km
2009 AV
Feb 16
44.9 LD
--
1.2 km
2000 ET70
Feb 19
17.7 LD
--
1.0 km
2011 CP4
Feb 23
9.1 LD
--
255 m
2008 EJ85
Mar 6
9.1 LD
--
44 m
1999 RD32
Mar 14
57.9 LD
--
2.3 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.
  Essential web links
NOAA Space Weather Prediction Center
  The official U.S. government space weather bureau
Atmospheric Optics
  The first place to look for information about sundogs, pillars, rainbows and related phenomena.
Solar Dynamics Observatory
  Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever.
STEREO
  3D views of the sun from NASA's Solar and Terrestrial Relations Observatory
Solar and Heliospheric Observatory
  Realtime and archival images of the Sun from SOHO.
Daily Sunspot Summaries
  from the NOAA Space Environment Center
Heliophysics
  the underlying science of space weather
Science Central
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