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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 359.3 km/sec
density: 0.1 protons/cm3
explanation | more data
Updated: Today at 2341 UT
X-ray Solar Flares
6-hr max: C1
2158 UT May25
24-hr: C1
2158 UT May25
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 25 May 11
Sunspot 1216 poses no threat for strong flares. Solar activity is very low. Credit: SDO/HMI

more images: from Gianluca Valentini of Rimini, Italy; from Jim Fakatselis of Huntington, NY;
Sunspot number: 23
What is the sunspot number?
Updated 24 May 2011

Spotless Days
Current Stretch: 0 days
2011 total: 1 day (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 820 days
Typical Solar Min: 486 days

Updated 24 May 2011

The Radio Sun
10.7 cm flux: 82 sfu
explanation | more data
Updated 24 May 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 1
explanation | more data
Interplanetary Mag. Field
Btotal: 5.5 nT
Bz: 1.6 nT north
explanation | more data
Updated: Today at 2344 UT
Coronal Holes: 25 May 11
A solar wind stream flowing from the indicated coronal hole could reach Earth on or about May 28th. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2011 May 25 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 May 25 2200 UTC
0-24 hr
24-48 hr
05 %
20 %
01 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
15 %
30 %
05 %
10 %
01 %
05 %
Wednesday, May. 25, 2011
What's up in space

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

Satellite flybys

VOLCANIC SUNSETS: Sky watchers in northern Europe should be alert for unusual sunsets as ash from Iceland's Grimsvotn volcano drifts through their part of the world. reader Vincint Phillips sends this example from Hale village near Liverpool, UK.

COMET FIREBALL: Residents of Atlanta, Georgia, and surrounding areas were startled on Friday night, May 20th around 10:47 EDT, when an object brighter than a full Moon streaked across the southern sky. "It appears to have been a disintegrating piece of comet," reports Bill Cooke of NASA's Meteoroid Environment Office. In a 1/3-speed video, recorded by a NASA fireball camera at the Tellus Science Museum in Cartersville, GA, fragments can be seen flying away from the bright exploding core.

Videos: full speed, 1/3 speed. Having troubles? Try Realplayer.

Using data from multiple cameras, Cooke was able to triangulate the fireball's flight path. "Before it hit Earth, this object was in an orbit much like that of Halley's Comet." That doesn't mean the fireball came from Halley's Comet itself, but rather that it belongs to the Halley Family. Cooke continues: "This icy, fragile object was about 2 meters wide, hit the atmosphere at a speed of 38.5 km/s (86,000 mph), and completely disintegrated about 60 km above ground." Observers along the ground track reported bright blue-green flashes, luminous sparkles, and distinct fireball-shadows. "It was the brightest event we've seen in the three year history of our meteor network," adds Cooke.

The comet-chunk broke into at least four fragments. Cooke is analyzing the dynamics of each one to learn more about the parent body and to find out if any pieces might have reached the ground. Stay tuned for updates.

THE SOLAR LIMB: "Despite the low sunspot number and weak flare activity, there is some action on the sun," reports amateur astronomer John Chumack of Dayton, Ohio. "I watched this forest of prominences grow over most of the day on May 23rd." (continued below)

Photo details: Lunt 60mm/50F H-Alpha solar telescope, DMK 21AF04 Fire-wire camera, 2x Barlow

"The solar limb is looking great," he says.

Indeed, it is. Today, NASA's Solar Dynamics Observatory is monitoring an even bigger plume of magnetized plasma rising over the sun's eastern horizon: image. These massive structures form without the aid of sunspots and can even produce their own flares if they collapse and fall to the stellar surface below. Readers with solar telescopes are encouraged to monitor developments.

more images: from Peter Desypris of Athens, Greece; from Cai-Uso Wohler of Bispingen, Germany; from Jesus Pelaez of Burgos, Spain

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

  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 May 25, 2011 there were 1224 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2011 HC24
May 12
5.9 LD
58 m
2002 JC
Jun 1
57.5 LD
1.6 km
2009 BD
Jun 2
0.9 LD
10 m
2002 JB9
Jun 11
71.5 LD
3.2 km
2001 VH75
Jun 12
42.2 LD
1.1 km
2004 LO2
Jun 15
9.9 LD
48 m
2011 GA55
Jul 6
64.1 LD
1.0 km
2011 EZ78
Jul 10
37.3 LD
1.6 km
2003 YS117
Jul 14
73.9 LD
1.0 km
2007 DD
Jul 23
9.3 LD
31 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
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
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  more links...
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