QUIET SUN: Solar activity is low. All of the sunspots on the Earthside of the sun are either stable or decaying. NOAA forecasters estimate no more than a 1% chance of M-class solar flares during the next 24 hours. Aurora alerts: text, voice.
THE COLORS INSIDE A LIGHTNING BOLT: To the human eye, a nearby flash of lightning looks blindingly white. But have you ever wondered what colors might emerge if the flash were spread out chromatically, like a rainbow? During a recent thunderstorm in Tarn, France, David Antao decided to find out. "I am an enthusiastic astro-spectroscopist," he says, "so I couldn't resist shooting some spectra." Here is the result:
"I found it really beautiful!" says Antao.
All of the colors of a rainbow are present in the lightning strike, but some colors are stronger than others. Red, green and blue emission lines zig-zag across the spectrum tracing the shape of the original bolt. These colors are mainly due to the recombination of electrons with nitrogen molecules broken apart and ionized by the searing heat of the lightning discharge. Lines from oxygen, hydrogen, and nitrogen oxides are present, too.
"By analysing this spectra, it is possible to determine the temprature of the lightning," notes Antao. "I am trying to do this now."
Realtime Space Weather Photo Gallery
CME MISSES EARTH, AURORAS APPEAR ANYWAY: The double-CME expected to hit Earth's magnetic field over the weekend either is late or missed entirely. In Alaska, the Northern Lights appeared anyway:
"Aurora season has officially started, and I am pleased to see her beauty again," says photographer Ryan Delos Reyes. "I took this shot from our neigborhood in Anchorage, Alaska, on August 25th."
Even without a CME impact, minor fluctuations in the solar wind were enough to ignite auroras around many parts of the Arctic Circle. Thanks to the waning of the summer midnight sun, the lights were visible for the first time in months. Browse the gallery for more signs that aurora season is underway.
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Solar wind
speed: 343.6 km/sec
density: 1.7 protons/cm3
explanation | more data
Updated: Today at 0146 UT
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X-ray Solar Flares
6-hr max: B3 1942 UT Aug26
24-hr: B5 1627 UT Aug26
explanation | more data
Updated: Today at: 2359 UT
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Daily Sun: 26 Aug 13
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None of these sunspots poses a threat for strong solar flares. Credit: SDO/HMI
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Sunspot number: 46
What is the sunspot number?
Updated 26 Aug 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 26 Aug 2013
The Radio Sun
10.7 cm flux: 113 sfu
explanation | more data
Updated 26 Aug 2013
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Current Auroral Oval:
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Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
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Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2 quiet
explanation | more data
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Interplanetary Mag. Field
Btotal: 5.9 nT
Bz: 1.1 nT south
explanation | more data
Updated: Today at 0147 UT
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Coronal Holes: 26 Aug 13
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Solar wind flowing from the indicated coronal hole should reach Earth on Aug. 30-31. Credit: SDO/AIA.
