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Solar wind
speed: 436.1 km/sec
density: 0.7 protons/cm3
explanation | more data
Updated: Today at 2347 UT
X-ray Solar Flares
6-hr max: C1
1954 UT Sep05
24-hr: C1
1954 UT Sep05
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 05 Sep 13
The Earthside of the sun is quiet. Solar activity is low. Credit: SDO/HMI
Sunspot number: 77
What is the sunspot number?
Updated 05 Sep 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

05 Sep 2013

The Radio Sun
10.7 cm flux: 109 sfu
explanation | more data
Updated 05 Sep 2013

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 2
explanation | more data
Interplanetary Mag. Field
Btotal: 4.2 nT
Bz: 2.3 nT north
explanation | more data
Updated: Today at 2347 UT
Coronal Holes: 04 Sep 13
Solar wind flowing from the indicated coronal hole should reach Earth on Sept. 5-6. Credit: SDO/AIA. 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: 09-02-2013 11:55:02
NOAA Forecasts
Updated at: 2013 Sep 05 2200 UTC
0-24 hr
24-48 hr
05 %
05 %
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 Sep 05 2200 UTC
0-24 hr
24-48 hr
10 %
10 %
01 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
15 %
15 %
15 %
15 %
10 %
10 %
Thursday, Sep. 5, 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

QUIET SUNSPOTS: All of the sunspots on the Earthside of the sun are stable and quiet. NOAA forecasters estimate a slight 5% chance of M-class solar flares and no more than a 1% chance of X-class flares on Sept. 4th. Solar flare alerts: text, voice.

SOLAR ECLIPSE: Twice every year, around the time of the equinoxes, Earth can pass directly between the Sun and NASA's Solar Dynamics Observatory (SDO), producing a series of beautiful eclipses from the point of view of the spacecraft. SDO's autumnal eclipse season began this week, producing a partial blackout of the sun:

During the eclipse, which was centered around 0658 UT on Sept. 2nd, Earth covered about half of the sun. Because these eclipses typically last for only minutes each day (maximum=72 minutes), there is still plenty of uninterrupted time for SDO to monitor activity on the sun. The ongoing eclipse season will end on Sept. 25th. Between now and then, stay tuned for some rare blackouts.

Realtime Space Weather Photo Gallery

GREEN LIGHT! Last night the Finnish Lapland turned green. Photographer B.Art Braafhart of Sala, Finland, documented the event with a short exposure on his digital camera:

"To the naked eye, it was more of a light background color," says Braafhart, "but green is green!"

The green color of auroras is a sign of molecular oxygen. When solar wind and magnetospheric electrons rain down on the upper atmosphere, they strike atoms and molecules in the air. Different species produce different colors: O2 glows green, N2 purple, and O red. Although nitrogen is more abundant than oxygen in Earth's atmosphere, the green glow of excited O2 is so intense (relatively speaking) that it often overwhelms the other colors.

More green lights are in the offing. NOAA forecasters estimate a 25% chance of polar geomagnetic storms on Sept. 5 and 6 when a solar wind stream is expected to buffet Earth's magnetic field. Aurora alerts: text, voice.

Realtime Aurora 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 September 5, 2013 there were 1424 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2013 RO5
Sep 1
8.3 LD
47 m
2013 RG
Sep 3
0.6 LD
6 m
2013 RZ5
Sep 4
1.1 LD
10 m
2013 QE16
Sep 5
8.2 LD
22 m
2013 RQ5
Sep 6
4.8 LD
27 m
2000 DK79
Nov 10
49.1 LD
3.2 km
2011 JY1
Nov 13
8.2 LD
57 m
2001 AV43
Nov 18
2.9 LD
58 m
2010 CL19
Nov 25
37.6 LD
1.3 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
Space Weather Alerts
  more links...
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