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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 422.4 km/sec
density: 2.8 protons/cm3
explanation | more data
Updated: Today at 2344 UT
X-ray Solar Flares
6-hr max: B4
1951 UT Aug27
24-hr: B8
0446 UT Aug27
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 27 Aug 11
The Earthside of the sun is peppered with small sunspots; none poses a threat for strong flares. Credit: SDO/HMI
Sunspot number: 76
What is the sunspot number?
Updated 26 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 26 Aug 2011

The Radio Sun
10.7 cm flux: 105 sfu
explanation | more data
Updated 26 Aug 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 2
explanation | more data
Interplanetary Mag. Field
Btotal: 4.2 nT
Bz: 1.5 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes: 27 Aug 11
A solar wind stream flowing from the indicated coronal hole should reach Earth on Aug. 28-29. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2011 Aug 27 2200 UTC
0-24 hr
24-48 hr
01 %
01 %
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 27 2200 UTC
0-24 hr
24-48 hr
20 %
20 %
05 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
30 %
25 %
15 %
10 %
01 %
01 %
Saturday, Aug. 27, 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

SUNSPOT BREAKTHROUGH: A new breakthrough in sunspot detection could provide days of extra early warning of solar storms heading for Earth. Get the full story from Science@NASA.

AURORA SEASON BEGINS: For the past five nights in a row, sky watchers around the Arctic Circle have witnessed green luminous tendrils dancing across the waning twilight of summer. It's safe to say: Aurora season has begun. Here is the view from Arjeplog, Sweden, just after midnight on August 27th:

"The sky cleared up at midnight and I went out to have a quick look for Northern Lights," says photographer Nenne ├ůman. "The sky turned green just as I reached the shores of Lake Hornavan--perfect timing. This was my first aurora this season, so I am very happy at the moment!"

The display could intensify this weekend when a solar wind stream is expected to reach Earth. High-latitude sky watchers should be on the lookout for first auroras. Aurora alerts: text, voice.

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

SUNSPOT MOVIE: Sunspots are planet-sized islands of magnetism floating in a fiery sea of solar plasma. Unlike the hard-rocky islands of Earth, however, the "firmament" of sunspots is in a constant state of flux. Boiling motions in the underlying plasma cause sunspot magnetic fields to move and shift, so that the active regions change shape on a daily basis. This movie from the Solar Dynamics Observatory shows the process at work in sunspot AR1271:

Readers, you can witness these changes with your own eyes using a safe sunspot telescope. Several new active regions are popping up across the solar disk, so there should be plenty of targets for sight-seeing this weekend.

more images: from Francois Rouviere of Mougins, France; from John Chumack of Dayton, Ohio; from Steve Wainwright of Gower S.Wales UK; from Pawel Warchal of Cracow, Poland

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 27, 2011 there were 1241 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2011 QE23
Aug 22
7.6 LD
32 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.
  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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