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Solar wind
speed: 495.4 km/sec
density: 5.0 protons/cm3
explanation | more data
Updated: Today at 2351 UT
X-ray Solar Flares
6-hr max: C1
2020 UT Sep25
24-hr: C2
0000 UT Sep25
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 25 Sep 15
Sunspot AR2420 has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares. Credit: SDO/HMI

Sunspot number: 86
What is the sunspot number?
Updated 25 Sep 2015

Spotless Days
Current Stretch: 0 days
2015 total: 0 days (0%)

2014 total: 1 day (<1%)
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%)

Updated 25 Sep 2015

The Radio Sun
10.7 cm flux: 107 sfu
explanation | more data
Updated 25 Sep 2015

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 3
explanation | more data
Interplanetary Mag. Field
Btotal: 6.1 nT
Bz: 3.0 nT north
explanation | more data
Updated: Today at 2350 UT
Coronal Holes: 25 Sep 15

Solar wind flowing from the indicated coronal hole should reach Earth on Sept. 26-27. Credit: SDO/AIA.
Noctilucent Clouds The northern season for NLCs is finished. According to NASA's AIM spacecraft, the last clouds were observed over Greenland on Aug. 27th. Now the waiting begins for the southern season expected to begin in November.
Switch view: Europe, USA, Asia, Polar
Updated at: 09-01-2015 09:00:00
NOAA Forecasts
Updated at: 2015 Sep 25 2200 UTC
0-24 hr
24-48 hr
35 %
35 %
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: 2015 Sep 25 2200 UTC
0-24 hr
24-48 hr
30 %
10 %
10 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
15 %
20 %
30 %
25 %
40 %
20 %
Friday, Sep. 25, 2015
What's up in space

On Sept. 27th, the Harvest Moon will pass through the shadow of Earth, turning the lunar disk a lovely shade of celestial red. Catch it live on the Internet, courtesy of the Coca-Cola Space Science Center in Columbus, Georgia.

Eclipse Webcast

CHANCE OF STORMS: NOAA forecasters estimate a 40% chance of minor geomagnetic storms on Sept 25th when a solar wind stream is expected to reach Earth. High-latitude sky watchers should be alert for auroras mixed with the waxing light of this weekend's full moon. Aurora alerts: text or voice

SUPERMOON ECLIPSE: This weekend's full Moon is a supermoon, the biggest and brightest full Moon of the year. And it is going to be eclipsed. On Sunday evening, Sept. 27th, the supermoon will pass through the shadow of Earth, turning the lunar disk a coppery shade of red. Click on the image, below, to view an animation of the eclipse and to find out when to look:

Sky watchers in the Americas, Europe, Africa, and eastern parts of Asia can see the event. The next total eclipse of the Moon won't come until January 31, 2018, so if you live in the eclipse zone, check it out.

What makes the eclipsed Moon turn red? A quick trip to the Moon provides the answer: Imagine yourself standing on a dusty lunar plain looking up at the sky. Overhead hangs Earth, nightside down, completely hiding the sun behind it. The eclipse is underway.

You might expect Earth seen in this way to be utterly dark, but it's not. The rim of the planet looks like it is on fire. As you scan your eye around Earth's circumference, you're seeing every sunrise and every sunset in the world, all of them, all at once. This incredible light beams into the heart of Earth's shadow, filling it with a coppery glow and transforming the Moon into a great red orb.

Red isn't the only color. There's also turquoise, shown here in a photo taken by Jens Hackman during an eclipse in March of 2007:

Its source is ozone. Atmospheric scientist Richard Keen of the University of Colorado explains: "During a lunar eclipse, most of the light illuminating the moon passes through the stratosphere where it is reddened by scattering. However, light passing through the upper stratosphere penetrates the ozone layer, which absorbs red light and actually makes the passing light ray bluer." This can be seen, he says, as a soft blue fringe around the red core of Earth's shadow.

To catch the turquoise on Sept. 27-28, he advises, "look during the first and last minutes of totality. The turquoise rim is best seen in binoculars or a small telescope."

Realtime Eclipse Photo Gallery

SPACE CORN FAILS TO APPETIZE: Regular readers of know that we have been flying simple life forms to the edge of space onboard helium balloons to test their response to space weather. Some fare better than others. Yeast, for instance, is incredibly tough. The microbes easily survive temperatures as low as -60 C and cosmic ray dose rates 100x Earth-normal. Corn, on the other hand, appears to be more fragile. In the spring of 2015, the students of Earth to Sky Calculus launched seed packets of corn and other vegetables to the stratosphere during geomagnetic storms. Bruce Binion bought some of these seeds as a gift for his father, a veteran farmer, who planted them alongside regular corn as an experiment. Here are the results:

"I must say this experience has been quite fascinating," reports Binion. "Compared to regular corn, the 'space corn' stalks were quite short, tasseled out quite early, and the ears were stunted. As can be seen in the picture, above, Dad has a normal, good-eating ear from the same garden area shown for reference beside a couple of ears grown from your space seeds."

In summary, cosmic rays do not seem to agree with corn. Sorry, astronauts!

Many readers have purchased packets of space seeds as a fund raiser for the research of Earth to Sky Calculus. Later this week we'll report some findings from a batch of stratospheric chile peppers. Stay tuned.

Realtime Space Weather Photo Gallery

Realtime Aurora Photo Gallery

Realtime Sprite Photo Gallery

  All Sky Fireball Network

Every night, a network of NASA all-sky cameras scans the skies above the United States for meteoritic fireballs. Automated software maintained by NASA's Meteoroid Environment Office calculates their orbits, velocity, penetration depth in Earth's atmosphere and many other characteristics. Daily results are presented here on

On Sep. 25, 2015, the network reported 19 fireballs.
(19 , 0 sporadics)

In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies]

  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 25, 2015 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
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
Columbia Northern High School
  Web-based high school science course with free enrollment
  more links...
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