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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 581.4 km/sec
density: 1.3 protons/cm3
explanation | more data
Updated: Today at 2341 UT
X-ray Solar Flares
6-hr max: C1
1949 UT Sep11
24-hr: C6
0851 UT Sep11
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 11 Sep 11
Sunspot 1283 has a "beta-gamma" magnetic field that harbors energy for strong M-class solar flares. Credit: SDO/HMI
Sunspot number: 77
What is the sunspot number?
Updated 10 Sep 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 10 Sep 2011

The Radio Sun
10.7 cm flux: 116 sfu
explanation | more data
Updated 10 Sep 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 3
explanation | more data
Interplanetary Mag. Field
Btotal: 4.8 nT
Bz: 2.2 nT south
explanation | more data
Updated: Today at 2343 UT
Coronal Holes: 11 Sep 11
A solar wind stream flowing from the indicated coronal hole should reach Earth on Sept. 12-13. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2011 Sep 11 2200 UTC
0-24 hr
24-48 hr
55 %
35 %
05 %
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 Sep 11 2200 UTC
0-24 hr
24-48 hr
20 %
20 %
10 %
10 %
05 %
05 %
High latitudes
0-24 hr
24-48 hr
30 %
30 %
10 %
10 %
05 %
05 %
Sunday, Sep. 11, 2011
What's up in space

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

Satellite flybys

HARVEST MOON: There's a full Moon tonight and it has a special name--the "Harvest Moon." It's the full Moon closest to the northern autumnal equinox. Before electric lights, farmers working late at night relied on the light of the Harvest Moon to gather their ripening autumn crops.

GEOMAGNETIC ACTIVITY: High-latitude sky watchers should be alert for auroras mixing with the light of tonight's Harvest Moon. A fast-blowing stream of solar wind is buffeting Earth's magnetic field and causing geoagnetic activity around the poles. Aurora alerts: text, voice.

A CME struck Earth's magnetic field on Sept. 9th, sparking more than 18 hours of bright auroras. In the United States, Northern Lights were spotted as far south as Washington, Wisconsin, Vermont, Montana, Maine, Minnesota and North Dakota. In Michigan, it was like a day at the beach:

Shawn Malone took the picture from the shores of Lake Superior near the city of Marquete. "Auroras appeared right after dusk, barely visible because of the moon," he says. "Gradually the fog moved in, creating a surreal landscape--the aurora and a fogbow!"

UPDATED: September 2011 Aurora Gallery
[previous Septembers: 2010, 2009, 2008, 2007, 2006, 2005, 2004]

TODAY's BONUS SHOTS: Launch of GRAIL from Ben Cooper of Cape Canaveral, Florida; Wave Clouds from Steve Jamruszka of Glacier National Park, Montana; Sundogs from Piet Berger of Simpelveld, the Netherlands;

SUNSPOT CONJUNCTION: A new sunspot (AR1289) is growing rapidly in the sun's eastern hemisphere. The International Space Station drew attention to it this morning when the solar-paneled spacecraft flew almost directly in front of the sunspot's dark core:


Maximilian Teodorescu took the picture from Magurele, Romania. "The space station made a very nice couplet with sunspot AR1289," he says. "This was the second ISS transit of the sun in three days for my location."

Readers, would like to try photographing your own ISS-sunspot conjunctions? Transit predictions are available from And, of course, you'll need a solar telescope.

more images: from Stephen W Ramsden of Atlanta, GA; from Theo Ramakers of Ruthlege, GA;

  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 September 11, 2011 there were 1244 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2003 QC10
Sep 18
50 LD
1.2 km
2004 SV55
Sep 19
67.5 LD
1.2 km
2007 TD
Sep 23
3.8 LD
58 m
2002 AG29
Oct 9
77.1 LD
1.0 km
2000 OJ8
Oct 13
49.8 LD
2.5 km
2009 TM8
Oct 17
1.1 LD
8 m
2011 FZ2
Nov 7
75.9 LD
1.6 km
2005 YU55
Nov 8
0.8 LD
175 m
1994 CK1
Nov 16
68.8 LD
1.5 km
1996 FG3
Nov 23
39.5 LD
1.1 km
2003 WM7
Dec 9
47.6 LD
1.5 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.
  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
  the underlying science of space weather
Science Central
Conquest Graphics
  for out-of-this-world printing and graphics
Trade Show Displays
  more links...
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