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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 366.7 km/sec
density: 2.0 protons/cm3
explanation | more data
Updated: Today at 2343 UT
X-ray Solar Flares
6-hr max: C1
1736 UT Nov13
24-hr: C2
0921 UT Nov13
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 13 Nov 11
All of the sunspots on the Earthside of the sun are quiet and pose little threat for geoeffective flares. Credit: SDO/HMI
Sunspot number: 155
What is the sunspot number?
Updated 13 Nov 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 13 Nov 2011

The Radio Sun
10.7 cm flux: 169 sfu
explanation | more data
Updated 13 Nov 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 0 quiet
24-hr max: Kp= 0
explanation | more data
Interplanetary Mag. Field
Btotal: 5.9 nT
Bz: 1.0 nT north
explanation | more data
Updated: Today at 0236 UT
Coronal Holes: 13 Nov 11
There are no large coronal holes on the Earthside of the sun. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2011 Nov 13 2200 UTC
0-24 hr
24-48 hr
20 %
10 %
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 Nov 13 2200 UTC
0-24 hr
24-48 hr
03 %
01 %
01 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
14 %
13 %
09 %
08 %
04 %
02 %
Sunday, Nov. 13, 2011
What's up in space

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

Satellite flybys

MERCURY-DIRECTED CME: A significant coronal mass ejection (CME) blasted away from the sun's eastern hemisphere on Nov. 12th. Analysts at the Goddard Space Weather Lab say the cloud will hit Mercury on Nov. 13th at 1800 UT (+/- 7 hr) followed by Venus about one day later. The innermost planets are about to experience space weather. [CME: movie, forecast track]

REMARKABLE SOLAR ACTIVITY: There haven't been any strong solar flares in days. Nevertheless, some impressive activity is underway on the sun. For one thing, an enormous wall of plasma is towering over the sun's southeastern horizon. Stephen Ramsden of Atlanta, Georgia, took this picture on Nov. 11th:

"Solar forums all over the world are buzzing with Sun-stronomers proclaiming this to be the biggest prominence that many of them had ever witnessed," he says.

Remarkably, though, this is not the biggest thing. A dark filament of magnetism is snaking more than halfway around the entire sun: SDO image. From end to end, it stretches more than a million km or about three times the distance between Earth and the Moon. If the filament becomes unstable, as solar filaments are prone to do, it could collapse and hit the stellar surface below, triggering a Hyder flare. No one can say if the eruption of such a sprawling structure would be Earth directed.

"I cant help but wonder what could possibly come next since we are still over a year away from the forecasted Solar Maximum," adds Ramsden. "There's never been a better time to own a solar telescope than now!"

more images: from Alan Friedman of Buffalo, NY; from Theo Ramakers of Social Circle, GA; from John Stetson of Falmouth, Maine; from Randy Shivak of Elyria, OH; from Steve Riegel of Albuquerque, NM; from Robert Arnold of Ilse of Skye, Scotland

DISAPPEARING TRICK: If you're a spy satellite, the ability to disappear could come in handy. US spysat Lacrosse 5 occasionally performs just such a trick. On Nov. 11th, satellite watcher Dr. Marco Langbroek of Leiden, the Netherlands, caught the orbiting radar suddenly fading to near invisibility:

"Lacrosse 5 is typically bright but occasionally performs what is known among observers as the 'disappearance trick,'" says Langbroek. "Its brightness suddenly drops 3 astronomonical magnitudes or more."

No one knows whether or not this is a deliberate form of stealth, but Langbroek doesn't think so: "Maybe some part of the spacecraft such as its solar panels casts a shadow over the main body," he speculates. "Or perhaps the surface of Lacrosse 5 becomes less reflective at certain viewing angles. This could happen as the craft suddenly changes attitude for some reason." Other Lacrosse satellites do not perform the trick, at least not to this extent, suggesting that the design of Lacrosse 5 differs from its predecessors.

"Later in the movie a bright Soyuz rocket booster (81-008B) passes by as well," he adds. "This is a piece of space debris connected to the 1981 launch of a Russian military satellite."

Readers, would you like to try catching the tricks of Lacrosse 5? Local flyby times may be found on the web or on your smartphone.

  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 November 13, 2011 there were 1256 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2011 FZ2
Nov 7
75.9 LD
1.6 km
2005 YU55
Nov 8
0.8 LD
400 m
2011 UT91
Nov 15
9.9 LD
109 m
1994 CK1
Nov 16
68.8 LD
1.5 km
1996 FG3
Nov 23
39.5 LD
1.1 km
2003 WM7
Dec 9
47.6 LD
1.6 km
1999 XP35
Dec 20
77.5 LD
1.0 km
2000 YA
Dec 26
2.9 LD
80 m
2011 SL102
Dec 28
75.9 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
Trade Show Displays
  more links...
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