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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 347.0 km/sec
density: 0.9 protons/cm3
explanation | more data
Updated: Today at 2343 UT
X-ray Solar Flares
6-hr max: M1
1701 UT Sep25
24-hr: M7
0450 UT Sep25
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 25 Sep 11
Sunspot 1302 poses a continued threat for X-class solar flares. Credit: SDO/HMI
Sunspot number: 88
What is the sunspot number?
Updated 24 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 24 Sep 2011


The Radio Sun
10.7 cm flux: 190 sfu
explanation | more data
Updated 24 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= 2
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 7.9 nT
Bz: 2.6 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes: 25 Sep 11
A solar wind stream flowing from the indicated coronal hole could reach Earth on Sept. 30th or Oct. 1st. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2011 Sep 25 2235 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
80 %
80 %
CLASS X
40 %
40 %
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 25 2235 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
45 %
30 %
MINOR
20 %
15 %
SEVERE
10 %
05 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
45 %
30 %
MINOR
25 %
15 %
SEVERE
15 %
05 %
 
Sunday, Sep. 25, 2011
What's up in space
 

Are we alone? Your iPhone has the answer. Download the all-new Drake Equation app to calculate the population of the Milky Way.

 
DrakeEQ for iPhone and iPad

GEOMAGNETIC STORM WARNING: A pair of closely-spaced CMEs propelled by explosions of sunspot AR1302 on Sept. 24th are heading not-quite directly toward Earth. A significant glancing blow to our planet's magnetic field is possible on Sept. 26th around 14:00 UT (+/- 7 hours). NOAA forecasters estimate a 30% chance of strong geomagnetic storms when the clouds arrive. [CME forecast track] Aurora alerts: text, voice.

STRONG SOLAR ACTIVITY: Having already unleashed two X-flares since Sept. 22nd, sunspot AR1302 appears ready for more. The active region has a complex "beta-gamma-delta" magnetic field that harbors energy for strong M- and X-class eruptions. Flares from AR1302 will become increasingly geoeffective as the sunspot turns toward Earth in the days ahead.

Marko Posavec of Koprivnica, Croatia, photographed the behemoth sunspot between flares on Sept. 24th:


Photo details: Olympus E-510, Sigma 50-500mm lens (at 500mm), 1/640 sec. exposure, f/18, ISO 100

"Sunspot complex 1302 is incredibly easy to spot at sunrise or sunset," says Posavec. "Be careful, though. Even the low-hanging sun is bright enough to damage your eyes if you look at it through optics of any kind." Safe solar filters may be found in the SpaceWeather Store.

more images: from Alan Friedman of Buffalo, NY; from Monika Landy-Gyebnar of Balatonfured, Hungary; from Piet Berger of Simpelveld, Netherlands; from Howard Eskildsen of Ocala, Florida; from Dzmitry Kananovich of Tallinn, Estonia; from Chris Schur of Payson, Az; from John Stetson of Falmouth, Maine; from Grenier of Paris France; from Maximilian Teodorescu of Magurele, Romania; from Cai-Uso Wohler of Bispingen, Germany; from Philippe Van den Doorn of Rixensart, Belgium

SOLAR STATIC: Active sunspot 1302 has turned the sun into a shortwave radio transmitter. Shock waves rippling from the sunspot's exploding magnetic canopy excite plasma oscillations in the sun's atmosphere. The result is bursts of static that may be heard in the loudspeakers of shortwave radios on Earth. Amateur radio astronomer Thomas Ashcraft recorded this sample from his backyard observatory in New Mexico on Sept. 24th:


Dynamic spectrum: The horizontal axis is time (h:m:s), the vertical axis is frequency (MHz). Image credit: Wes Greenman

"Saturday was a super-strong solar day with near continuous flaring and radio sweeps," says Ashcraft. "The sound file (above) corresponds to an M3 flare at 1918 UTC. It was the strongest radio sweep of the observing day."

"Try listening to the radio bursts in stereo," he advises. "I was recording on two separate radios at 21.1 MHz and 21.9 MHz, and I put each one into its own channel of the audio file. This gives a spatial dimension as the bursts sweep down in frequency."


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

  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 25, 2011 there were 1250 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
2011 SQ32
Sep 20
7.5 LD
--
44 m
2011 SK68
Sep 21
5.8 LD
--
13 m
2007 TD
Sep 22
6.2 LD
--
58 m
2011 SE58
Sep 27
0.6 LD
--
13 m
2011 SO5
Sep 29
5.6 LD
--
34 m
2002 AG29
Oct 9
77.1 LD
--
1.0 km
2011 SS25
Oct 12
69.8 LD
--
1.1 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
 
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