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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 422.4 km/sec
density: 0.2 protons/cm3
explanation | more data
Updated: Today at 2344 UT
X-ray Solar Flares
6-hr max: B6
1839 UT Oct26
24-hr: C1
0925 UT Oct26
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 26 Oct 11
Sunspot 1330 has a "beta-gamma" magnetic field that harbors energy for M-class solar flares.Credit: SDO/HMI
Sunspot number: 147
What is the sunspot number?
Updated 25 Oct 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 25 Oct 2011


The Radio Sun
10.7 cm flux: 139 sfu
explanation | more data
Updated 25 Oct 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 1
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 4.9 nT
Bz: 1.8 nT south
explanation | more data
Updated: Today at 2346 UT
Coronal Holes: 26 Oct 11
A solar wind stream flowing from the indicated coronal hole could brush past Earth on Oct. 29-30. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2011 Oct 26 2205 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
10 %
10 %
CLASS X
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 Oct 26 2205 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
05 %
10 %
MINOR
01 %
01 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
15 %
MINOR
05 %
10 %
SEVERE
01 %
01 %
 
Wednesday, Oct. 26, 2011
What's up in space
 

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Own your own meteorite

SUBSIDING STORM: The intense geomagnetic storm of Oct. 24-25 (described below) has subsided and US skies are returning to normal. If you missed the show, don't worry. The Northern Lights will be back. For much of the past few years, the sun has been in a quiet state; but solar activity is cyclical and the sun appears to be waking up again. Forecasters expect new Solar Cycle 24 to peak in 2012-2013 with many more chances to see auroras in unfamiliar places. Aurora alerts: text, voice.

AURORAS IN THE USA: A coronal mass ejection (CME) hit Earth on Oct. 24th at approximately 1800 UT (2:00 pm EDT). The impact strongly compressed Earth's magnetic field, directly exposing geosynchronous satellites to solar wind plasma, and sparked an intense geomagnetic storm. As night fell over North America, auroras spilled across the Canadian border into the contiguous United States. A US Department of Defense satellite photographed the crossing:

"This shows the auroras on Oct. 25th at 0140 GMT," says Paul McCrone of the Fleet Numerical Meteorology and Oceanography Center in Monterey, California. He created the image using visual and infrared data from the Defense Meteorological Satellite Program's F18 polar orbiter. DMSP satellites carry low light cameras for nightime monitoring of moonlit clouds, city lights and auroras. Some of the auroras recorded by the F18 on Oct. 25th were as bright as the city lights underneath.

This "big picture" from orbit makes sense of what happened next. The bright band swept south and, before the night was over, auroras were sighted in more than thirty US states: Alabama, Wisconsin, New Mexico, Tennessee, Missouri, Illinois, Nebraska, Kentucky, North Carolina, Indiana, Oklahoma, Kansas, Iowa, Maryland, New York, Montana, Ohio, Colorado, Pennsylvania, Washington, Virginia, Texas, Arizona, Minnesota, Maine, Michigan, Montana, Oregon, Arkansas and California.

Many observers, especially in the deep south, commented on the pure red color of the lights they saw. These rare all-red auroras sometimes appear at low latitudes during intense geomagnetic storms. They occur some 300 to 500 km above Earth's surface and are not yet fully understood.

UPDATED: October 2011 Aurora Gallery
[previous Octobers: 2010, 2009, 2008, 2007, 2006, 2004, 2003, 2002]

THE INSTIGATING EXPLOSION: The CME that hit Earth's magnetic field on Oct. 24th left the sun almost two days earlier. It was propelled in our direction by an unstable magnetic filament, which erupted around 0100 UT on Oct. 22nd. This movie from the Solar and Heliospheric Observatory shows the cloud expanding toward Earth in the first hours after the explosion:

Traveling faster than two million mph, the cloud took about 41 hours to cross the sun-Earth divide. The CME was so geoeffective because it contained a knot of south-pointing magnetic fields. These fields partially cancelled Earth's north-pointing magnetic field at the equator, allowing solar wind plasma to penetrate deeply into Earth's magnetosphere. The rest, as they say in Alabama, is history.

  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 October 26, 2011 there were 1256 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
2011 UC64
Oct 24
1.3 LD
--
11 m
2011 UH10
Oct 24
9.6 LD
--
17 m
2011 FZ2
Nov 7
75.9 LD
--
1.6 km
2005 YU55
Nov 8
0.8 LD
--
200 m
2011 UT91
Nov 14
9.8 LD
--
95 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
--
1.5 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.
STEREO
  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
Heliophysics
  the underlying science of space weather
Science Central
 
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