You are viewing the page for Aug. 13, 2011
  Select another date:
<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 347.0 km/sec
density: 13.2 protons/cm3
explanation | more data
Updated: Today at 2343 UT
X-ray Solar Flares
6-hr max: B1
2300 UT Aug13
24-hr: B1
2300 UT Aug13
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 12 Aug 11
None of these small sunspots poses a threat for strong flares. Credit: SDO/HMI
Sunspot number: 25
What is the sunspot number?
Updated 11 Aug 2011

Spotless Days
Current Stretch: 0 days
2011 total: 1 day (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 820 days
Typical Solar Min: 486 days

Updated 11 Aug 2011

The Radio Sun
10.7 cm flux: 84 sfu
explanation | more data
Updated 11 Aug 2011

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2
explanation | more data
Interplanetary Mag. Field
Btotal: 5.4 nT
Bz: 0.1 nT north
explanation | more data
Updated: Today at 2344 UT
Coronal Holes: 12 Aug 11
Solar wind flowing from the indicated coronal should reach Earth on or about Aug. 15th. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2011 Aug 13 2200 UTC
0-24 hr
24-48 hr
01 %
01 %
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 Aug 13 2200 UTC
0-24 hr
24-48 hr
40 %
30 %
10 %
10 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
40 %
35 %
15 %
15 %
05 %
05 %
Saturday, Aug. 13, 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

GOT CLOUDS? If you can't see this weekend's Perseid meteor shower, try listening instead. Each time a Perseid flies over Texas, the US Air Force's Space Surveillance Radar records a ghostly echo. Tune into Space Weather Radio for live audio.

PERSEID METEOR SHOWER: The Perseid meteor shower is peaking today, August 13th, as Earth passes through a stream of debris from Comet Swift-Tuttle. Observers from the International Meteor Organization report rates as high as 60 meteors per hour and climbing.

David Blanchard sends this report from Sunset Crater National Monument in Arizona: "A nearly full Moon along with thin clouds wiped out many of the dimmer meteors, but the brightest Perseids were still easy to see." In this image he captured a Perseid almost criss-crossing the International Space Station:

The ISS is the brighter streak; the Perseid appears more clearly in this close-up. "It is one thing to photograph the ISS as it transits the sky. It is quite another to hope that a meteor will have the location and timing to be in the same image. So I consider myself quite fortunate to have captured an ISS-Perseid conjunction," says Blanchard.

More ISS-Perseid conjunctions could be in the offing as the space station continues to fly through the night sky during this period of high meteor activity. Check the Simple Satellite Tracker for ISS flyby times--and be alert for Perseids.

What sat was that? The hours before dawn are a great time to see satellites. There are hundreds in Earth orbit, and you're sure to spot some of them while you're watching the Perseids. Your Android phone can tell you which ones you're seeing: Download WhatSat.

more Perseid images: from John Chumack of Dayton, Ohio; from Michal Lachký of Slovakia Skýcov, castle Hrušov; from Ferenc and Dr. Földesi of Veszprém-Csatár, Hungary; from Stefano De Rosa of Isola d' Elba (Italy); from Philippe Moussette of Valcartier Québec Canada; from Olivier Staiger of Vétroz in the Swiss Alps; from Monika Landy-Gyebnar of Veszprem, Hungary

August 2011 Aurora Gallery
[previous Augusts: 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002]

2011 Noctilucent Cloud Gallery
[previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009]

  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 August 13, 2011 there were 1241 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2011 PE2
Jul 30
3.5 LD
108 m
2011 OJ45
Aug 17
4.6 LD
28 m
2009 AV
Aug 22
49.7 LD
1.1 km
2003 QC10
Sep 18
50 LD
1.2 km
2004 SV55
Sep 19
67.5 LD
1.2 km
2007 TD
Sep 23
3.8 LD
58 m
2002 AG29
Oct 9
77.1 LD
1.0 km
2000 OJ8
Oct 13
49.8 LD
2.5 km
2009 TM8
Oct 17
1.1 LD
8 m
2011 FZ2
Nov 7
75.9 LD
1.6 km
2005 YU55
Nov 8
0.8 LD
175 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
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.
©2019 All rights reserved.