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Solar wind
speed: 375.4 km/sec
density: 3.9 protons/cm3
explanation | more data
Updated: Today at 2346 UT
X-ray Solar Flares
6-hr max: B8
1701 UT Jul15
24-hr: C3
1055 UT Jul15
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 15 July 13
AR1791 is crackling with C-class solar flares. Credit: SDO/HMI
Sunspot number: 88
What is the sunspot number?
Updated 15 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

15 Jul 2013

The Radio Sun
10.7 cm flux: 113 sfu
explanation | more data
Updated 15 Jul 2013

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 5
explanation | more data
Interplanetary Mag. Field
Btotal: 4.3 nT
Bz: 2.7 nT north
explanation | more data
Updated: Today at 2347 UT
Coronal Holes: 15 Jul 13
Solar wind flowing from the indicated coronal hole could reach Earth on July 19-20. 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: 07-15-2013 12:55:02
NOAA Forecasts
Updated at: 2013 Jul 15 2200 UTC
0-24 hr
24-48 hr
25 %
25 %
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 15 2200 UTC
0-24 hr
24-48 hr
15 %
20 %
05 %
05 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
20 %
20 %
25 %
30 %
20 %
25 %
Monday, Jul. 15, 2013
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

CONTEST! WAVE AT SATURN, WIN A TELESCOPE: On July 19th, the Cassini spacecraft will photograph Earth through the rings of Saturn. NASA hopes people will go out and wave at Saturn during the photoshoot. How about waving at Saturn from the edge of space? Enter the Wave at Saturn Contest and your idea to commemorate Cassini's snapshot could be flown to the stratosphere on July 19th. Winners will receive free telescopes from Explore Scientific. Enter now!

MINOR MAGNETIC UNREST: A CME swept past Earth on July 13th. Its impact was gentle, but the CME's wake is unsettling the geomagnetic field. Last night, July 14-15, magnetometers registered a minor (Kp=5) geomagnetic storm for nearly six hours. High-latitude sky watchers should remain alert for auroras as CME effects subside. Aurora alerts: text, voice.

Michel Tournay of James Bay, Canada was outside on on July 14 when the sky turned as green as the trees:

"What started as a lightning-photography evening ended up being an great opportunity to photograph the Northern Lights," says Tournay.

There might be another opportunity tonight. NOAA forecasters estimate a 40% chance of polar geomagnetic storms on July 15th.

Realtime Aurora Photo Gallery

SPACE WEATHER BALLOON UPDATE: Last month, a record-setting heat wave swept across the southwestern USA, with temperatures in Death Valley and surrounding areas jumping as high as 54 C (129 F). The student scientists of Earth to Sky Calculus decided to find out if the heat wave extended all the way to the edge of space. So, on June 30th when the temperature in their hometown Bishop, CA, was 42 C (108 F), they launched a research balloon to the stratosphere. An onboard cryogenic thermometer measured the temperature all the way up to 90,000 feet above sea level. This is what they found:

The heat wave did not reach into the stratosphere.

During the flight, the thermometer registered a low temperature of -64.4 C. This occured when the balloon passed through the tropopause, the boundary layer between the troposphere and the stratosphere. The tropopause is the coldest part of the atmosphere, and on the day of the heat wave it was just as cold as usual. Consider the following histogram:

Since 2011, the Earth to Sky students have flown 30 balloons and measured the temperature of the tropopause 19 times. The histogram is a summary of their thermal database, which spans all four seasons and all 12 months of the year. The temperature of the tropopause on June 30, 2013, fell right in the middle of the distribution--nothing unusual. These results show that hot air on the ground does not necessarily translate into a hot upper atmosphere.

There was, however, something unusual about the flight. Normally, air above the Sierra launch site is crystal clear, but not this time. En route to the stratosphere, the balloon encountered many thin layers of smoke and ash blown into the area from distant wildfires. Each fire, apparently, lofted its aerosols to a different altitude where winds stretched the smoky debris into a thin layer. This picture was captured while the balloon was in transit between two layers:

Note the curved blue line. That's the narrow gap between the two aerosol layers, allowing a glimpse of blue sky in the distance. (To residents of the eastern Sierra: That's Crowley Lake in the foreground.)

This was a curiosity-driven experiment conducted by high school students. Learn more about the Earth to Sky Calculus program at the group's Facebook page.

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 15, 2013 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
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.
  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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