You are viewing the page for Sep. 28, 2011
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 446.1 km/sec
density: 0.9 protons/cm3
explanation | more data
Updated: Today at 2343 UT
X-ray Solar Flares
6-hr max: B5
1748 UT Sep28
24-hr: M1
1328 UT Sep28
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 28 Sep 11
Sunspot 1302 poses a continued threat for X-class solar flares. Credit: SDO/HMI
Sunspot number: 82
What is the sunspot number?
Updated 27 Sep 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 27 Sep 2011

The Radio Sun
10.7 cm flux: 139 sfu
explanation | more data
Updated 27 Sep 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 5
explanation | more data
Interplanetary Mag. Field
Btotal: 6.3 nT
Bz: 2.7 nT north
explanation | more data
Updated: Today at 2346 UT
Coronal Holes: 28 Sep 11
There are no large coronal holes on the Earthside of the sun. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2011 Sep 28 2205 UTC
0-24 hr
24-48 hr
50 %
50 %
30 %
30 %
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 Sep 28 2205 UTC
0-24 hr
24-48 hr
15 %
05 %
01 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
20 %
10 %
05 %
01 %
01 %
01 %
Wednesday, Sep. 28, 2011
What's up in space

They came from outer space--and you can have one! Genuine meteorites are now on sale in the Space Weather Store.

Own your own meteorite

MAGNETIC AFTERSHOCKS: A minor geomagnetic storm erupted earlier today, Sept. 28th, causing beautiful Wednesday-morning auroras in Canada and some northern-tier US states. These are, essentially, aftershocks of the severe storm on Sept. 26th. More reverberations are possible tonight. Aurora alerts: text, voice.

A NIGHT TO REMEMBER: A coronal mass ejection (CME) hit Earth's magnetic field around noon Universal Time on Sept. 26th. The impact set the stage for a night to remember. As soon as darkness fell over Scandinavia, auroras filled the sky with such intensity that they were visible through rain clouds. Fredrik Broms photographed the scene from Kvaløya, Norway:

"These were some of the most amazing auroras I have ever seen," says Broms, a longtime observer of the Arctic lights. "The colours were absolutely stunning with purple and deep blood-red in addition to the green. It was a night I will never forget!

Sky watchers at the highest latitudes should remain alert for auroras as Earth's magnetic field continues to reverberate from the CME impact. Aurora alerts: text, voice.

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

BIG SUNSPOT: The source of the CME that hit Earth on Sept. 26th is sunspot AR1302. Measuring more than 150,000 km from end to end, the sprawling active region is visible even without a solar telescope. Here it is among the seagulls at sunset on Sept. 27th:

Damien Vens took the picture from the beach in Koksijde, Belgium. "I used an off-the-shelf Nikon D7000 digital camera," he says. "The sunspot was an easy target." (Note to photographers: Never look at the sun through unfiltered optics such as camera viewfinders; even a low-hanging sun can be blindingly bright.)

AR1302 has quieted down since unleashing dual X-flares on Sept. 22nd and 24th. Nevertheless, NOAA forecasters estimate a 25% chance of more X-flares during the next 24 hours. Any such eruptions would be Earth-directed as the sunspot crosses the center of the solar disk. Solar flare alerts: text, voice.

more images: from James W. Young of Seaside, Oregon; from Andy Devey of Barnsley South Yorkshire; from J. Stetson and students in Hinckley, Maine; from Ali Norouzi of Karaj, Iran; from Theo Ramakers of Social Circle, GA; from Stefano Sello of Pisa, Italy; from Phil Greaves of Sydney Australia; from Stefan Plach of Stadt Wehlen, Saxony, Germany;

  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 September 28, 2011 there were 1250 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2007 TD
Sep 22
6.2 LD
58 m
2011 SE58
Sep 27
0.6 LD
13 m
2011 SC108
Sep 27
1.2 LD
12 m
2011 SO5
Sep 29
5.6 LD
34 m
2002 AG29
Oct 9
77.1 LD
1.0 km
2011 SE97
Oct 12
7.9 LD
52 m
2011 SS25
Oct 12
69.8 LD
1.2 km
2000 OJ8
Oct 13
49.8 LD
2.4 km
2009 TM8
Oct 17
0.9 LD
8 m
2011 FZ2
Nov 7
75.9 LD
1.6 km
2005 YU55
Nov 8
0.8 LD
175 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
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.