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Solar wind
speed: 347.2 km/sec
density: 5.1 protons/cm3
explanation | more data
Updated: Today at 2348 UT
X-ray Solar Flares
6-hr max: B2
2029 UT Sep01
24-hr: B3
0705 UT Sep01
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 01 Sep 15
With only a few small sunspots dotting the solar disk, the Earth-facing side of the sun is nearly blank. Credit: SDO/HMI

Sunspot number: 50
What is the sunspot number?
Updated 01 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 01 Sep 2015

The Radio Sun
10.7 cm flux: 91 sfu
explanation | more data
Updated 01 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= 2
explanation | more data
Interplanetary Mag. Field
Btotal: 5.1 nT
Bz: 1.3 nT south
explanation | more data
Updated: Today at 2018 UT
Coronal Holes: 01 Sept. 15

A stream of solar wind flowing from the indicated coronal hole should reach Earth on or about Sept. 3rd. 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 to begin sometime in November.
Switch view: Europe, USA, Asia, Polar
Updated at: 09-01-2015 09:00:00
NOAA Forecasts
Updated at: 2015 Sep 01 2200 UTC
0-24 hr
24-48 hr
01 %
01 %
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 01 2200 UTC
0-24 hr
24-48 hr
40 %
30 %
25 %
15 %
05 %
05 %
High latitudes
0-24 hr
24-48 hr
10 %
10 %
25 %
25 %
60 %
50 %
Tuesday, Sep. 1, 2015
What's up in space

Marianne's Heaven On Earth Aurora Chaser Tours invites you to join them in their quest to find and photograph the Aurora Borealis. Experience the winter wonderland in the Tromsø Area.

Chase the Light Tours

SOLAR SECTOR BOUNDARY CROSSNG: High-latitude auroras are possible on Sept. 2nd when Earth crosses through a fold in the heliospheric current sheet. This is called a "solar sector boundary crossing," and NOAA forecasters estimate a 70% chance of polar geomagnetic storms when it occurs. Aurora alerts: text or voice

ALMOST-BLANK SUN: The sunspot number is plummeting, and the Earth-facing side of the sun is almost blank. Scan this image, taken on Sept. 1st by NASA's Solar Dynamics Observatory, to see how many dark cores you can find:

There are only a few tiny spots, circled here. Not one of them has the type of unstable magnetic field that harbors energy for strong flares. As a result, the sun's X-ray output is flatlining. NOAA forecasters estimate a 5% chance of M-flares and no more than a 1% chance of X-flares during the next 24 hours. Solar flare alerts: text or voice

Realtime Space Weather Photo Gallery

SPACE STATION TRANSITS A PROMINENCE: In recent years, astrophotographers have become increasingly adept at catching the International Space Station during split-second transits of the sun. The winged form of the behemoth spaceship looks beautiful when backlit by fiery plasma, and on more than one occasion it has been seen in conjunction with active sunspots. Now, for perhaps the first time, Thierry Legault of Paris, France, has captured the silhouette of the ISS passing in front of a solar prominence:

"This was no accident," says Legault. "Using Calsky to predict the circumstances of the transit, I positioned my telescope 1 mile north of the central transit line so that the ISS would pass directly between me and the prominence."

His pinpoint preparations worked, and he captured more than 30 video frames of the ISS zooming across the face of the sun. The complete crossing may be seen on Youtube.

Solar observers are paying extra attention to prominences this week because that is almost the only thing to see. With only a few small sunspots dotting the solar disk, the face of the sun is nearly featureless. Plumes of plasma rising over the sun's limb are the photo-op du jure--even better when a spaceship joins the show.

Realtime Space Weather Photo Gallery

THE SPACE PIZZA EXPERIMENT: Regular readers of know that we have been flying colonies of yeast to the edge of space to study the effect of cosmic rays on their biology. But yeast aren't just for science. They also make great pizza. To support our program, Emily Winter purchased some yeast packets from the stratosphere, and she has a report to share: "My friends and I made a pizza with your space yeast. We had so much fun!" Their video is a must-see:

The yeast packets Emily and her friends used to bake "space pizza" were exposed to extreme conditions in the stratosphere: air pressures less than 1% of sea level, temperatures as low as -60 C, and cosmic ray dose rates nearly 100x Earth-normal. Despite this harsh treatment, the yeast returned to Earth with more than enough vitality to puff up a delicious pizza crust. This is in accord with our scientific measurements of yeast survival rates--in some cases greater than 90%. The microbes are extremely tough and can easily survive near-space travel.

Emily and friends say the space pizza tasted much like normal pizza, but it did have an unexpected side effect. Watch the video all the way to the end for their revelation.

Realtime Aurora Photo Gallery

Realtime Sprite Photo Gallery

Realtime NLC 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. 1, 2015, the network reported 51 fireballs.
(50 sporadics, 1 alpha Aurigid)

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 1, 2015 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2015 QT3
Aug 28
4.2 LD
71 m
2015 PT227
Aug 29
9.7 LD
69 m
2004 BO41
Aug 31
57.3 LD
1.2 km
1991 CS
Sep 4
62.1 LD
1.4 km
2014 KS76
Sep 14
8.7 LD
22 m
2004 TR12
Sep 15
58.8 LD
1.0 km
2000 FL10
Oct 10
65.7 LD
1.9 km
2011 QD48
Oct 17
67.5 LD
1.0 km
2014 UR
Oct 18
3.8 LD
21 m
2011 SE97
Oct 18
12 LD
50 m
2001 UY4
Oct 21
58.2 LD
1.0 km
2005 UL5
Nov 20
5.9 LD
390 m
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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