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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 437.9 km/sec
density: 0.3 protons/cm3
explanation | more data
Updated: Today at 2344 UT
X-ray Solar Flares
6-hr max: B6
1952 UT Feb20
24-hr: C1
0357 UT Feb20
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 20 Feb 11
Sunspot complex 1161-1162 poses a threat for Earth-directed M-class solar flares. Credit: SDO/HMI
Sunspot number: 79
What is the sunspot number?
Updated 19 Feb 2011

Spotless Days
Current Stretch: 0 days
2011 total: 1 day (2%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 820 days
Typical Solar Min: 486 days

Updated 19 Feb 2011

The Radio Sun
10.7 cm flux: 109 sfu
explanation | more data
Updated 19 Feb 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 3
explanation | more data
Interplanetary Mag. Field
Btotal: 3.8 nT
Bz: 1.3 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes: 18 Feb 11
There are no large equatorial coronal holes on the Earth-side of the sun. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2011 Feb 20 2200 UTC
0-24 hr
24-48 hr
60 %
60 %
05 %
05 %
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 Feb 20 2200 UTC
0-24 hr
24-48 hr
05 %
05 %
01 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
05 %
05 %
01 %
01 %
01 %
01 %
Sunday, Feb. 20, 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

MEANWHILE ON THE FARSIDE: For the past week, all eyes have been on the Earth-side of the sun, where sunspots 1158 and 1161-1162 have unleashed some of the strongest flares in years. Meanwhile, the farside of the sun has been busy, too. Regard this movie from NASA's STEREO-B probe covering the first 20 hours of Feb. 19th. A huge active region is transiting the farside and crackling with flares; it will turn toward Earth in about a week. What's the best way to keep track of the sun's farside? Download 3D Sun for the iPhone and iPad. (Note: An Android version will soon be available.)

WEEKEND AURORAS: On Saturday night, Feb. 19th, the interplanetary magnetic field (IMF) near Earth tipped south. This opened a crack in Earth's magnetosphere; solar wind poured in and fueled a display of Northern Lights around the Arctic Circle:

"It was a truly wonderful night," says photographer Andy Keen of Inari, FInland. "We were out until 2am taking pictures of auroras dancing over the moonlit landscape."

Readers, would you like to see scenes like this with your own eyes? Keen is willing to take you on an aurora tour. Click here for details.

UPDATED: February 2011 Aurora Photo Gallery
[previous Februaries: 2010, 2009, 2008, 2007, 2006, 2004, 2003, 2002]

FLICKERING SOLAR SAIL: NASA has joined forces with to stage a solar sail photography competition. Top prize: $500. Peter Rosen hasn't won yet, but with this movie of NanoSail-D, he has definitely entered the contest:

Photo details: Canon EOS 5D Mk II, 85/1.2 lens @ 1.2, 55 one-sec exposures at ISO 3200.

Not to be confused with the airliner at the top of the photo, NanoSail-D is the star-like object below denoted by a cross. Watch the movie again and note how the sail flickers in the inset circle.

Rosen describes what happened: "I photographed NanoSail-D from Stockholm, Sweden, on Feb. 4th. The sail was very low on the horizon, but I was able to catch it using my Canon EOS 5D digital camera. I estimate its magnitude between 6 and 7."

"There are many other satellites in the field of view and some airplanes coming in for landing at the local airport," he continues. "NanoSail-D behaves very differently from other satellites as its visibility seems to pulsate in short flashes sometimes several per second. This image zooms in on the phenomenon. I wonder if it due to small changes in the sail's direction and thus reflectivity?"

Indeed, sunlight is almost certainly glinting off the sail's reflective fabric. Researchers believe these flickers could, from time to time, develop into spectacular flares, outshining the brightest stars and perhaps even exceeding the luminosity of Iridium flares. At the moment, these flares are unpredictable because the sail's orientation is not known precisely enough to forecast sun-glints. The only way to catch one is to go outside and look.

NanoSail-D flyby times: on the web, on your cell phone.

  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 February 20, 2011 there were 1198 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2011 CD66
Feb 13
7.2 LD
18 m
2011 CL50
Feb 19
6.2 LD
12 m
2003 YG118
Feb 20
67.7 LD
1.8 km
2000 PN9
Mar 10
45.5 LD
2.6 km
2002 DB4
Apr 15
62.5 LD
2.2 km
2008 UC202
Apr 27
8.9 LD
10 m
2009 UK20
May 2
8.6 LD
23 m
2008 FU6
May 5
75.5 LD
1.2 km
2003 YT1
May 5
65.3 LD
2.5 km
2002 JC
Jun 1
57.5 LD
1.6 km
2009 BD
Jun 2
0.9 LD
9 m
2002 JB9
Jun 11
71.5 LD
3.2 km
2001 VH75
Jun 12
42.2 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
Conquest Graphics
  for out-of-this-world printing and graphics
Science Central
  more links...
©2010 All rights reserved. This site is penned daily by Dr. Tony Phillips.
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