You are viewing the page for Oct. 24, 2011
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 498.0 km/sec
density: 9.3 protons/cm3
explanation | more data
Updated: Today at 2343 UT
X-ray Solar Flares
6-hr max: B7
2114 UT Oct24
24-hr: B9
0442 UT Oct24
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 24 Oct 11
Sunspot 1324 has a beta-gamma magnetic field that harbors energy for Earth-directed M-flares. Credit: SDO/HMI

more images: from Michael Borman of Evansville, Indiana; from Stephen W. Ramsden of Atlanta, GA; from Rogerio Marcon of Campinas SP Brasil
Sunspot number: 128
What is the sunspot number?
Updated 23 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 23 Oct 2011

The Radio Sun
10.7 cm flux: 156 sfu
explanation | more data
Updated 23 Oct 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 5 storm
24-hr max: Kp= 5
explanation | more data
Interplanetary Mag. Field
Btotal: 18.9 nT
Bz: 15.6 nT south
explanation | more data
Updated: Today at 2344 UT
Coronal Holes: 24 Oct 11
There are no large coronal holes on the Earthside of the sun. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2011 Oct 24 2200 UTC
0-24 hr
24-48 hr
20 %
20 %
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 24 2200 UTC
0-24 hr
24-48 hr
40 %
30 %
05 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
50 %
40 %
15 %
10 %
01 %
01 %
Monday, Oct. 24, 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

CME IMPACT: A CME hit Earth's magnetic field on Oct. 24th at approximately 1800 UT (02:00 pm EDT). Acording to analysts at the Goddard Space Weather Lab, the impact caused a strong compression of Earth's magnetic field, allowing solar wind to penetrate all the way down to geosynchronous orbit for a brief period between 19:06 UT and 19:11 UT. Earth-orbiting spacecraft could have been directly exposed to solar wind plasma during that time.

The impact also sparked a geomagnetic storm, underway now. Geir Øye sends this picture from Ørsta, Norway:

"The sky was brightly illuminated by auroras this evening," says Øye. "The picture, above, was taken at 19.20 UT [just after the most extreme compression of the magnetosphere]."

High-latitude sky watchers should remain alert for auroras as Earth's magnetic field continues to reverberate from the CME impact. The best time to look is usually during the hours around local midnight. Aurora alerts: text, voice.

Also: Strong ground currents have been detected in Norway.

COMET CORPSE: "Doomsday Comet" Elenin was briefly famous for inaccurate predictions that it might hit Earth. Instead it disintegrated as it approached the sun last month. (Doomsday canceled.) Over the weekend, Italian astronomer Rolando Ligustri spotted the comet's remains. It's the elongated cloud in this Oct. 22nd photo of the star field where Elenin would have appeared if it were still intact:

Another team of astronomers--Ernesto Guido, Giovanni Sostero and Nick Howes--spotted the cloud on the same night. At first they were skeptical. "The cloud was extremely faint and diffuse," says Guido. "We wondered if it might be scattered moonlight or some other transient artifact." But when the team looked again on Oct. 23, the cloud was still there. A two-night blink animation shows that the cloud is moving just as the original comet would have. Note: Some readers have noticed a fast-moving streak to the to the lower right of the debris cloud. That is an unrelated asteroid, 2000 OJ8 (magnitude 14), which happened to be in the field of view at the same time as the cloud of Elenin.

More information about this discovery and continued tracking of the "comet corpse" may be found at the Remanzacco Observatory Astronomy Blog.

SPACE WEATHER FORECAST FOR MARS: A bright CME blasted off the sun yesterday, Oct. 22nd, and it appears to be heading for Mars. Analysts at the Goddard Space Weather Lab expect the cloud to reach the Red Planet on Oct. 26th (forecast track). A brief discussion of what CMEs can do to Mars follows this SOHO image of the eruption:

Mars has a unique response to solar storms shaped by the planet's strange magnetic topology. Unlike Earth, which has a global magnetic field, Mars is patchily covered by dozens of "magnetic umbrellas"--remnants of an over-arching planetary field that decayed billions of years ago. When Mars gets hit by a CME, the resulting magnetic storms take place in the umbrellas. Circumstantial evidence collected by Mars Global Surveyor in the 1990s suggests that the tops of the umbrellas light up with bright ultraviolet auroras during such storms. Because the structures are distributed around the planet, these auroras can appear even at the equator.

Mars rovers and satellites should be alert for aurora equatoralis on Oct. 26th.

Bonus: Magnetic umbrellas are at the heart of one of Mars's greatest mysteries: What happened to the atmosphere? Billions of years ago, the air on Mars was thick enough to protect vast expanses of water on the planet’s surface. Now, however, the atmosphere is 100 times thinner than Earth's and the surface is bone dry. Some researchers believe that magnetic storms in the umbrellas could rip parcels of atmosphere away from Mars and propel air-filled magnetic bubbles into space. In this way, space weather could be directly responsible for the desiccation of the Red Planet.

September 2011 Aurora Gallery
[previous Septembers: 2010, 2009, 2008, 2007, 2006, 2005, 2004]

  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 24, 2011 there were 1256 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2011 UL10
Oct 21
3.5 LD
39 m
2011 UC64
Oct 24
1.3 LD
12 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
9.7 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.
  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
Conquest Graphics
  for out-of-this-world printing and graphics
Trade Show Displays
  more links...
©2010 All rights reserved. This site is penned daily by Dr. Tony Phillips.
©2013 All rights reserved.