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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 413.5 km/sec
density: 0.1 protons/cm3
explanation | more data
Updated: Today at 2344 UT
X-ray Solar Flares
6-hr max: B2
2123 UT Feb22
24-hr: B6
1048 UT Feb22
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 22 Feb 11
NOAA forecasters estimate a 50% chance of M-class flares from departing sunspot complex 1161-1162 during the next 24 hours. Credit: SDO/HMI
Sunspot number: 60
What is the sunspot number?
Updated 21 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 21 Feb 2011

The Radio Sun
10.7 cm flux: 97 sfu
explanation | more data
Updated 21 Feb 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 0 quiet
24-hr max: Kp= 1
explanation | more data
Interplanetary Mag. Field
Btotal: 4.9 nT
Bz: 0.1 nT north
explanation | more data
Updated: Today at 2345 UT
Coronal Holes: 21 Feb 11
A solar wind stream flowing from this shallow coronal hole could brush past Earth on Feb. 23rd or 24th. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2011 Feb 22 2200 UTC
0-24 hr
24-48 hr
05 %
05 %
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 Feb 22 2200 UTC
0-24 hr
24-48 hr
10 %
10 %
01 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
10 %
10 %
01 %
01 %
01 %
01 %
Tuesday, Feb. 22, 2011
What's up in space

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

Satellite flybys

SPACESHIP SIGHTINGS: The International Space Station (ISS) is flying over North America this week. It's visible after sunset as a streaking light brighter than Jupiter or Venus. Check the Simple Satellite Tracker for flyby times--and be alert for solar sails, too!

ISS flyby images: from Pete Lardizabal of St Johns, Florida; from Christopher Calubaquib of El Sobrante,California; from Kevin Palivec of Hawley, Texas;

NORTHERN LIGHTS: Blowing at 450 km/s, an unexpected solar wind stream hit Earth's magnetic field during the late hours of Feb. 21st. The impact did not spark a strong geomagnetic storm, but auroras appeared around the Arctic Circle anyway. Helge Mortensen sends this picture from Ersfjordbotn, just outside Tromsø, Norway:

"I thought it was going to be just another boring night," says Mortensen. "Luckily I was wrong. We had a great show!" Browse the gallery for more scenes from last night.

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.

NEW: NanoSail-D Photo Gallery
[NASA: Solar Sail Stunner] [Photo Contest]

  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 22, 2011 there were 1198 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2011 CL50
Feb 19
6.2 LD
13 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
2004 LO2
Jun 15
9.9 LD
48 m
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.
Spaceweather Flybys

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