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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 487.4 km/sec
density: 0.5 protons/cm3
explanation | more data
Updated: Today at 2343 UT
X-ray Solar Flares
6-hr max: B5
1735 UT Aug24
24-hr: C1
1633 UT Aug24
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 24 Aug 11
Sunspot 1271 poses a declining threat for M-class solar flares. Credit: SDO/HMI
Sunspot number: 81
What is the sunspot number?
Updated 23 Aug 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 23 Aug 2011


The Radio Sun
10.7 cm flux: 104 sfu
explanation | more data
Updated 23 Aug 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Planetary K-index
Now: Kp= 0 quiet
24-hr max: Kp= 3
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 3.2 nT
Bz: 3.1 nT south
explanation | more data
Updated: Today at 2344 UT
Coronal Holes: 24 Aug 11
A solar wind stream flowing from the indicated coronal hole should reach Earth on Aug. 27-28. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2011 Aug 24 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
10 %
10 %
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 Aug 24 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
15 %
MINOR
01 %
01 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
15 %
MINOR
01 %
01 %
SEVERE
01 %
01 %
 
Wednesday, Aug. 24, 2011
What's up in space
 

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

 
Satellite flybys

RUSSIAN CARGO ROCKET LOST: An unmanned Russian rocket carrying 2.9 tons of supplies for the International Space Station failed to reach orbit today when its third stage failed almost six minutes after liftoff. The Interfax news agency reported the Progress 44 spacecraft re-entered the atmosphere over eastern Russia. More information: #1, #2, #3

COLDEST STARS DISCOVERED: Stars as cold as the human body? Believe it. A NASA spacecraft has discovered a half-dozen "Y dwarfs" with atmospheric temperatures as low as 80 F. Get the full story from Science@NASA.

NORTHERN LIGHTS: A solar wind stream hit Earth's magnetic field during the early hours of Augist 24th, sparking geomagnetic activity around the Arctic Circle. "Bright, fast-moving auroras lit up the sky just after midnight," reports Sean M. Scully, who sends this picture from Akureyri, Iceland:

Hours after impact, the solar wind is still blowing at high speed (500+ km/s) but the density of the wind is declining rapidly. This diminishes its ability to rattle Earth's magnetic field and thus produce Northern Lights. Neverthelesss, polar skies could turn green again tonight; NOAA forecasters estimate a 15% chance of continued geomagnetic activity. Aurora alerts: text, voice.

more images: from Bjarki Mikkelsen of Jokkmokk Porjus, Lapland, Sweden.

August 2011 Aurora Gallery
[previous Augusts: 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002]

VOLCANIC SUNSETS: Sky watchers in Europe should be alert for volcanic sunsets. "For the past week, we've seen unusual twilight rays probably caused by high-attitude aerosols from Nabro, a volcano which erupted in Eritrea on June 13th," reports Petr Horalek from the Ondřejov Observatory of the Astronomical Institute of the Academy of Sciences of the Czech Republic. This is how the sky looked on Aug. 23rd:

"Around 20 minutes after sunset these significant crepuscular rays appeared like shining fingers in the western sky," he describes. "The rays were so strong, I could see them almost directly overhead; and in the south, they stretched across the horizon like great red and purple stripes."

Purple is one of the telltale colors of a volcanic sunset. Fine volcanic aerosols in the stratosphere scatter blue light which, when mixed with ordinary sunset red, produces a violet hue. Another set of photos taken last night by Martin Popek in the Czech city of Nýdek highlights the purple signature.

More examples of volcanic sunsets may be found here and here.


2011 Noctilucent Cloud Gallery
[previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009]

  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 August 24, 2011 there were 1241 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
2011 OJ45
Aug 17
4.6 LD
--
29 m
2009 AV
Aug 22
49.7 LD
--
1.1 km
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
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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Trade Show Displays
   
  more links...
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