~12~31~11~ Space Weather Update~A minor solar wind stream is buffeting Earth's magnetic field [1]
~Space Weather Update~
METEORITE MYSTERY: Earth is mysteriously peppered with fragments of giant asteroid Vesta. (Here's a piece [2] you can have for yourself.) New observations from NASA's Dawn spacecraft suggest an explanation involving one of the tallest mountains in the Solar System. Get the full story [3] from Science@NASA [4].
LAST AURORAS OF 2011? A minor solar wind stream is buffeting Earth's magnetic field with just enough force to ignite Northern Lights around the Arctic Circle. Hanneke Luijting of Tromsø, Norway, photographed the scene on Dec. 30th:
"It was amazing, I just sat there in the snow next to my tripod staring up into the sky, not believing my eyes!" says . "What a way to end 2011."
The show might not be over yet. There are still some hours left until 2012, and more auroras are possible as the solar wind continues to blow. Aurora alerts: text [6], voice [7].
more images: from Frank Olsen [8] of Vesterålen, Norway; from Helge Mortensen [9] of Brensholmen outside Tromsø; from Chad Blakley [10] of Abisko National Park, Sweden; from Göran Strand [11] of Aspås, Sweden; from P-M Hedén [12] of Tänndalen, Sweden; from Beate Kiil Karlsen [13] of Norway; from Andy Keen [14] on the Finnish-Russian border
Solar wind
speed: 335.4 km/sec
density: 9.3 protons/cm3
explanation [15] | more data [16]
Updated: Today at 1305 UT
X-ray Solar Flares
6-hr max: B6 1250 UT Dec31
24-hr: B6 0000 UT Dec31
explanation [17] | more data [18]
Updated: Today at: 1300 UT
Daily Sun: 31 Dec 11
Sunspot 1389 poses a continued threat for M-class [20] solar flares. Credit: SDO/HMI
Sunspot number: 104
What is the sunspot number? [21]
Updated 30 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 30 Dec 2011
The Radio Sun
10.7 cm flux: 141 sfu
explanation [22] | more data [23]
Updated 30 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 [25] | more data [26]
Interplanetary Mag. Field
Btotal: 4.7 nT
Bz: 1.4 nT north
explanation [27] | more data [28]
Updated: Today at 1327 UT
Coronal Holes: 31 Dec 11
Solar wind flowing from this coronal hole will buffet Earth's magnetic field from now until ~Jan. 2. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts

Updated at: 2011 Dec 30 2200 UTC
Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active [30], minor storm [30], severe storm [30]
Updated at: 2011 Dec 30 2200 UTC
Mid-latitudes
High latitudes
Category:
- Ground Crew Updates [32]