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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 345.5 km/sec
density: 6.4 protons/cm3
explanation | more data
Updated: Today at 2346 UT
X-ray Solar Flares
6-hr max: C6
2129 UT Dec28
24-hr: C7
1425 UT Dec28
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 28 Dec 11
Sunspots 1386 and 1387 have "beta-gamma" magnetic fields that harbor energy for M-class solar flares. Credit: SDO/HMI
Sunspot number: 126
What is the sunspot number?
Updated 27 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 27 Dec 2011


The Radio Sun
10.7 cm flux: 140 sfu
explanation | more data
Updated 27 Dec 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 12.1 nT
Bz: 6.5 nT north
explanation | more data
Updated: Today at 2345 UT
Coronal Holes: 28 Dec 11
A solar wind stream flowing from this coronal hole could reach Earth between Dec. 29th and 30th. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2011 Dec 28 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
40 %
40 %
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 28 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
25 %
15 %
MINOR
10 %
05 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
15 %
MINOR
25 %
20 %
SEVERE
20 %
20 %
 
Wednesday, Dec. 28, 2011
What's up in space
 

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

 
Satellite flybys

CHANCE OF MAGNETIC STORMS: NOAA forecasters estimate a 20% to 40% chance of polar geomagnetic storms on Dec. 28-29 in response to the arrival of one or more CMEs. High-latitude sky watchers should be alert for auroras. Aurora alerts: text, voice.

ON MARS, TOO: Sunspot 1387 erupted on Christmas day, hurling a coronal mass ejection (CME) directly toward Mars. According to analysts at the Goddard Space Weather Lab, impact will occur on Dec. 30th at 1800 UT (+/- 7 hr). Click to view an animated forecast track:

Unlike Earth, Mars does not have a global magnetic field. Instead, the Red Planet has "magnetic umbrellas." These are fossil remnants of an ancient global magnetic field that decayed billions of years ago. When a CME hits Mars, the action happens in the umbrellas' canopies. Because the umbrellas are scattered around Mars, martian auroras can theoretically occur even near the equator.

Different world, different space weather.

MOTHER OF PEARL: As December draws to a close, the first polar straospheric clouds of northern winter are forming around the Arctic Circle. P-M Hedén photographed the phenomenon last night over Tänndalen, Sweden:

"Wow, what a lovely sight!" says Hedén. "They appeared in the sunset sky next to Venus and the crescent Moon."

Also known as "nacreous" or "mother of pearl" clouds, these icy clouds 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.

"Nacreous clouds far outshine and have much more vivid colours than ordinary iridescent clouds, which are very much poor relations and seen frequently all over the world," writes atmospheric optics expert Les Cowley. "Once seen they are never forgotten."

more images: from Krystian Rosa of Brandbu, Norway; from Patricia Cowern of Porjus,Sweden

  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 28, 2011 there were 1272 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
2000 YA
Dec 26
2.9 LD
--
80 m
2011 SL102
Dec 28
75.9 LD
--
1.0 km
2011 WS95
Dec 28
7.1 LD
--
46 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
Trade Show Displays
   
  more links...
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