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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 405.0 km/sec
density: 0.3 protons/cm3
explanation | more data
Updated: Today at 2344 UT
X-ray Solar Flares
6-hr max: C5
2230 UT Sep22
24-hr: X1
1102 UT Sep22
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 22 Sep 11
A big new sunspot is emerging at the circled location. Credit: SDO/HMI
Sunspot number: 108
What is the sunspot number?
Updated 21 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 21 Sep 2011


The Radio Sun
10.7 cm flux: 144 sfu
explanation | more data
Updated 21 Sep 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= 1
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 5.2 nT
Bz: 1.2 nT north
explanation | more data
Updated: Today at 2346 UT
Coronal Holes: 21 Sep 11
There are no large coronal holes on the Earth-facing side of the sun. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2011 Sep 22 2225 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
70 %
70 %
CLASS X
20 %
20 %
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 22 2225 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
10 %
10 %
MINOR
01 %
01 %
SEVERE
01 %
01 %
 
Thursday, Sep. 22, 2011
What's up in space
 

Metallic photos of the sun by renowned photographer Greg Piepol bring together the best of art and science. Buy one or a whole set. They make a stellar gift.

 
Metallic pictures of the Sun

MAJOR X-FLARE + CME UPDATE: Earth-orbiting satellites have detected a long-duration X1.4-class solar flare coming from a new sunspot on the sun's eastern limb. The blast, which peaked at 1100 UT, produced a significant coronal mass ejection (CME). Using data from the SOHO-STEREO fleet of spacecraft, analysts at the Goddard Space Weather Lab have modeled the trajectory of the CME and concluded that the body of the cloud will not hit Earth. A minor glancing encounter with the outskirts of the CME is, however, possible on Sept. 25th. [CME: movie, forecast track]

AURORAS UNDERFOOT: Solar activity is picking up, and no one has a better view of its effect on Earth than the crew of the International Space Station. During a geomagnetic storm on Sept. 17th, astronauts recorded a must-see movie of auroras dancing underfoot:


Taken over the southern Indian Ocean, the movie spans a 23-min period from 17:22:27 to 17:45:12 GMT on Sept. 17.

Note how the underbelly of the space station glows green from the reflected light of the auroras below. Also, in the distance, Sirius the dog star and Orion the Hunter can be seen rising feet-first into the night sky.

The storm, which registered a moderate 6 on the 0-to-9 K-index scale of geomagnetic disturbances, was caused by a coronal mass ejection (CME) hitting Earth's magnetic field. It was just a glancing blow, but with CMEs that is often enough to spark bright auroras over both ends of Earth. The space station was flying over the southern hemisphere at the time of the display. Observers in the northern hemisphere saw it too.

A similar storm could be in the offing this week. Another CME is heading toward Earth, and it appears likely to deliver a glancing blow on Sept. 22nd around 23:00 UT. Sky watchers above and below should be alert for auroras. Aurora alerts: text, voice.

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

RE-ENTRY ALERT: NASA's UARS satellite is making its final orbits around Earth, tumbling and flashing brightly as it descends toward a Sept. 23rd re-entry. Amateur astronomer Jim Saueressig II caught the bus-sized satellite flying over Burlington, Kansas, on Sept. 20th (image). "It was easily visible in spite of the moonlight and the twilight of the sunrise. The tumble and associated flares were very apparent," he says.

Satellite tracking expert Ted Molczan has used USSTRATCOM's orbital elements of UARS to predict a decay time "late on Sep 23, roughly between 18:00 and 22:00 UTC." Click on the map to view ground tracks corresponding to this interval:

"There is still potential for the estimated time of decay to shift somewhat before it begins to narrow down," cautions Molczan.

The disintegration of UARS is expected to produce a fireball that could be visible even in broad daylight. Not all of the spacecraft will burn up in the atmosphere, however; according to a NASA risk assessment, as many as 26 potentially hazardous pieces of debris could be scattered along a ground track some 500 miles long. The same report puts the odds of a human casualty at 1 in 3200.

For last-chance sightings of this brightly flashing satellite, please check the Simple Satellite Tracker or download the Satellite Flybys app for your smartphone.

more images: from Theirry Legault of Dunkerque, France; from Oscar Martín Mesonero of Madrid, Spain;

  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 22, 2011 there were 1244 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
2003 QC10
Sep 18
50 LD
--
1.2 km
2004 SV55
Sep 19
67.5 LD
--
1.2 km
2007 TD
Sep 22
6.2 LD
--
58 m
2011 SO5
Sep 29
5.6 LD
--
35 m
2002 AG29
Oct 9
77.1 LD
--
1.0 km
2000 OJ8
Oct 13
49.8 LD
--
2.4 km
2009 TM8
Oct 17
0.9 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.
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
 
Conquest Graphics
  for out-of-this-world printing and graphics
Trade Show Displays
   
  more links...
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