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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
 
Solar wind
speed: 411.6 km/sec
density: 3.8 protons/cm3
explanation | more data
Updated: Today at 2342 UT
X-ray Solar Flares
6-hr max: C3
2115 UT Aug04
24-hr: M9
0357 UT Aug04
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 04 Aug 11
Sunspots 1261 and 1263 pose a continued threat for X-class solar flares. Credit: SDO/HMI
Sunspot number: 66
What is the sunspot number?
Updated 03 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 03 Aug 2011


The Radio Sun
10.7 cm flux: 120 sfu
explanation | more data
Updated 03 Aug 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= 2
quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 7.9 nT
Bz: 3.2 nT south
explanation | more data
Updated: Today at 2344 UT
Coronal Holes: 04 Aug 11
A solar wind stream flowing from the indicated coronal hole should reach Earth on Aug. 7th or 8th. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2011 Aug 04 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
75 %
75 %
CLASS X
15 %
15 %
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 04 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
30 %
MINOR
35 %
30 %
SEVERE
50 %
20 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
30 %
MINOR
30 %
30 %
SEVERE
55 %
30 %
 
Thursday, Aug. 4, 2011
What's up in space
 

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

 
Satellite flybys

STRONG SOLAR ACTIVITY: For the third day in a row, active sunspot 1261 has unleashed a significant M-class solar flare. The latest blast at 0357 UT on August 4th registered M9.3 on the Richter Scale of Flares, almost crossing the threshold into X-territory (X-flares are the most powerful kind). The number of energetic protons around Earth has jumped nearly 100-fold as a result of this event.

The eruption propelled a bright coronal mass ejection (CME) toward Earth. Click on the image to view a movie of the expanding cloud recorded by the Solar and Heliospheric Observatory:


Note: The many speckles in this movie are caused by energetic solar protons hitting the camera.

Moving at an estimated speed of 1950 km/s, this CME is expected to sweep up two earlier CMEs already en route. Analysts at the GSFC Space Weather Lab say the combined cloud should reach Earth on August 5th at 13:55 UT plus or minus 7 hours: "The impact on Earth is likely to be major. The estimated maximum geomagnetic activity index level Kp is 7 (Kp ranges from 0 - 9). The flanks of the CME may also impact STEREO A, Mars and Mercury/MESSENGER." High-latitude sky watchers should be alert for auroras. Aurora alerts: text, voice.

July 2011 Aurora Gallery
[previous Julys: 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003]

SPOTTED SUNSETS: During the recent years of deep solar minimum, observers of the sunset grew accustomed to a blank solar disk. News flash: The sunspots are back. "The sunset conditions of August 2nd were just right to show the massive sunspots AR1260, AR1261 and AR1263 to the casual observer who happened to glance at the sun for a brief few moments," reports Stephen W. Ramsden of Atlanta, Georgia. "You could even see the penumbra with the naked eye!" He had a camera handy and snapped this picture:

"The size and broiling movement of these sunspots just boggles the mind," he says. "You could fit every planet in the solar system with all of the known asteroids neatly inside the largest group...wow!"

Caution: Even when the sun is dimmed by low-hanging clouds or haze, focused sunlight can still damage your eyes. Do not look at the sun through unfiltered optics of any kind. A safely-filtered White Light Solar Observing System is the best way to monitor these great sunspots.

TODAY'S BONUS SHOTS: Find the Bee from Tim Erney of Corvallis, Oregon; Solar Radio Waves from Gauribidanur Rajasekhara of the University of Mauritius in Bras d’Eu, Flacq.; Comet-Star Cluster Conjunction from Dave Weixelman of Nevada City, California; Spotted Sunrise from Andreas Walker of Hallwil, Switzerland;


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 4, 2011 there were 1241 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
2007 DD
Jul 23
9.3 LD
--
31 m
2003 BK47
Jul 26
77.6 LD
--
1.1 km
2011 OD18
Jul 28
0.4 LD
--
22 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.
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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