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Solar wind
speed: 452.1 km/sec
density: 1.1 protons/cm3
explanation | more data
Updated: Today at 2347 UT
X-ray Solar Flares
6-hr max: C2
1757 UT Jul11
24-hr: C2
1757 UT Jul11
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 11 July 13
Sunspot complex AR1785-87 is in decay, but it still has a complex magnetic field that harbors energy for X-class solar flares. Credit: SDO/HMI
Sunspot number: 76
What is the sunspot number?
Updated 11 Jul 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 Jul 2013

The Radio Sun
10.7 cm flux: 118 sfu
explanation | more data
Updated 11 Jul 2013

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Planetary K-index
Now: Kp= 4 unsettled
24-hr max: Kp= 5
storm
explanation | more data
Interplanetary Mag. Field
Btotal: 4.7 nT
Bz: 0.0 nT
explanation | more data
Updated: Today at 2347 UT
Coronal Holes: 11 Jul 13
There are no large coronal holes on the Earthside of the sun. Credit: SDO/AIA.

Spaceweather.com is now posting daily satellite images of noctilucent clouds (NLCs), which hover over Earth's poles at the edge of space. The data come from NASA's AIM spacecraft. The north polar "daisy" pictured below is a composite of near-realtime images from AIM assembled by researchers at the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP).
Noctilucent Clouds
Switch view: Europe, USA, Asia, Polar
Updated at: 07-11-2013 10:55:02
SPACE WEATHER
NOAA Forecasts
Updated at: 2013 Jul 11 2200 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
30 %
25 %
CLASS X
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: 2013 Jul 11 2200 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
20 %
35 %
MINOR
05 %
15 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
15 %
15 %
MINOR
25 %
30 %
SEVERE
25 %
40 %
 
Thursday, Jul. 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

DECAYING SUNSPOT: Formerly-huge sunspot AR1785 is decaying, but it still has a 'beta-gamma-delta' magnetic field that harbors energy for X-class solar flares. It's noteworthy that AR1785 has posed a flare-threat for days without actually exploding. Decaying could undermine the stability of the sunspot's magnetic field and make a flare more likely. Solar flare alerts: text, voice.

CONTINUED MINOR STORMING: Intermittent geomagnetic storms are underway as Earth passes through the wake of a CME that arrived on July 9th. Auroras have been sighted in New Zealand, Canada, and several northern-tier US states. Shawn Malone sends this picture from Marquette, Michigan, where the auroras appeared at sunrise on July 11th:

"We got some nice activity right before the sunlight washed out the sky this morning," says Malone. "July auroras are such a treat."

The instigating CME was a minor one, and its impact was weak. Nevertheless, it has been effective in sparking high-latitude auroras because its wake contains a south-pointing magnetic field. This "negative Bz" opens a crack in Earth's magnetosphere, allowing solar wind to pour in and fuel the Northern and Southern Lights.

So far the storms in this episode have maxed out at Kp=5, the lowest level of geomagnetic storming. Fitful displays of high-latitude auroras could continue for the next 24 hours as CME effects subside. Aurora alerts: text, voice.

Realtime Aurora Photo Gallery

GREEN SKIES OVER TEXAS: Not all green lights in the sky are the aurora borealis. Astrophotographer Kenneth Edwards discovered this for himself on July 4th when he was taking a long exposure of the Milky Way over Big Bend National Park, Texas:

"For the long 4th of July weekend I went with my daughter to Big Bend National Park to try some time lapse photography of the Milky Way," says Edwards. "After getting back home, I was creating a time lapse video when I noticed the green colors. They were not visible to the naked eye but it sure was clear in the pictures and videos."

The green light is called "airglow." Airglow is a luminous bubble that surounds our entire planet, fringing the top of the atmosphere with aurora-like color. Although airglow resembles the aurora borealis, its underlying physics is different. Airglow is caused by an assortment of chemical reactions in the upper atmosphere driven mainly by solar ultraviolet radiation; auroras, on the other hand, are ignited by gusts of solar wind.

Green airglow is best photographed from extremely dark sites on nights when the Moon is new or below the horizon. It often shows up in long exposures of the Milky Way: more airglow.

Realtime Space Weather Photo Gallery


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


Realtime Comet Photo Gallery

  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 July 11, 2013 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Size
2013 NH4
Jul 6
4.3 LD
30 m
2013 NJ4
Jul 7
3.9 LD
14 m
2001 PJ9
Jul 17
29.2 LD
1.1 km
2006 BL8
Jul 26
9.3 LD
48 m
2003 DZ15
Jul 29
7.6 LD
153 m
2005 WK4
Aug 9
8.1 LD
420 m
1999 CF9
Aug 23
24.7 LD
1.1 km
2002 JR9
Aug 31
63.5 LD
1.4 km
1992 SL
Sep 23
70 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.
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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