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Solar wind
speed: 452.7 km/sec
density: 2.4 protons/cm3
explanation | more data
Updated: Today at 2347 UT
X-ray Solar Flares
6-hr max: C3
2300 UT Apr11
24-hr: M6
0716 UT Apr11
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 11 Apr 13
Sunspots AR1718 and AR1719 pose a threat for M-class solar flares. Credit: SDO/HMI
Sunspot number: 163
What is the sunspot number?
Updated 11 Apr 2013

Spotless Days
Current Stretch: 0 days
2013 total: 0 days (0%)
2012 total: 0 days (0%)
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Since 2004: 821 days
Typical Solar Min: 486 days

Update
11 Apr 2013

The Radio Sun
10.7 cm flux: 148 sfu
explanation | more data
Updated 11 Apr 2013

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: 4.8 nT
Bz: 1.8 nT south
explanation | more data
Updated: Today at 2347 UT
Coronal Holes: 11 Apr 13
There are no large coronal holes on the Earthside of the sun. Credit: SDO/AIA.
SPACE WEATHER
NOAA Forecasts
Updated at: 2013 Apr 11 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
50 %
50 %
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: 2013 Apr 11 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
30 %
MINOR
01 %
35 %
SEVERE
01 %
10 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
10 %
MINOR
15 %
20 %
SEVERE
10 %
60 %
 
Thursday, Apr. 11, 2013
What's up in space
 

When is the best time to see auroras? Where is the best place to go? And how do you photograph them? These questions and more are answered in a new book, Northern Lights - a Guide, by Pal Brekke & Fredrik Broms.

 
Northern Lights - a Guide

MINOR RADIATION STORM: Energetic solar protons are flying past Earth today. The particles were accelerated in our direction by the M6-class flare of April 11th (see below). They can be seen hitting and speckling the detector of the SOHO spacecraft in this movie of the explosion (labeled image). NOAA ranks the ongoing radiation storm as S1, which is considered a minor event. Solar flare alerts: text, voice.

STRONG SOLAR FLARE: The magnetic field of sunspot AR1719 erupted on April 11th at 0716 UT, producing an M6-class solar flare. NASA's Solar Dynamics Observatory recorded the explosion's extreme ultraviolet flash:

Coronagraph images from the Solar and Heliospheric Observatory (SOHO) show a CME emerging from the blast site. The expanding cloud should hit Earth's magnetic field during the early hours of April 13th, possibly sparking geomagnetic storms and auroras. Aurora alerts: text, voice.

Click to play a movie of the CME recorded by (SOHO):

The speckles near the end of the movie are caused by energetic solar protons hitting the coronagraph's CCD detector; the particles were accelerated in the direction of the spacecraft by the flare.

Note that although the CME appears to hit Mars and Venus, there is no actual physical contact. The cloud is merely passing in front of the two planets. Stay tuned for updates about this significant explosion.

Realtime Space Weather Photo Gallery

COMET ISON UPDATE: In November 2013, Comet ISON could become one of the brightest and most active comets in years when it races through the hot atmosphere of the sun. Right now, though, it is just a dim speck in the deep-freeze of space near the orbit of Jupiter. Alberto Quijano Vodniza photographed the barely-visible comet on April 7th from his private observatory in Pasto, Narino, Colombia:

Comet ISON may look underwhelming, but that is only because it is so far away, more than 400 million miles from the sun. In fact, it is already an active comet with considerable promise. Recent measurements by NASA's Swift spacecraft shows that the comet's nucleus is spewing more than 112,000 pounds (51,000 kg) of dust, or about two-thirds the mass of an unfueled space shuttle, every minute. To produce so much dust, the comet's nucleus is probably about 5 km wide. For comparison, the nucleus of bright sungrazing Comet Lovejoy, which wowed observers in 2011, was only about one-tenth as large. Comet ISON could put on quite a show when it approaches the sun later this year.

More about Comet ISON: NASA video, 3D orbit, ephemeris, light curves.

Realtime Comet Photo Gallery


Realtime Aurora Photo Gallery


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

  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 April 11, 2013 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Size
2013 GW38
Apr 7
1.3 LD
9 m
2013 GB55
Apr 12
9.8 LD
31 m
2010 GM23
Apr 13
3.9 LD
50 m
2013 GH23
Apr 19
5.5 LD
33 m
2005 NZ6
Apr 29
24.9 LD
1.3 km
2001 DQ8
Apr 30
74.3 LD
1.1 km
2004 BV102
May 25
69.9 LD
1.4 km
1998 QE2
May 31
15.2 LD
2.1 km
2000 FM10
Jun 5
50.3 LD
1.3 km
2002 KL3
Jun 6
66.4 LD
1.1 km
1999 WC2
Jun 12
39.2 LD
1.9 km
2006 RO36
Jun 18
70.9 LD
1.2 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
Space Weather Alerts
   
  more links...
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