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Solar wind
speed: 469.0 km/sec
density: 5.5 protons/cm3
explanation | more data
Updated: Today at 2348 UT
X-ray Solar Flares
6-hr max: C1
2238 UT Feb28
24-hr: C5
0939 UT Feb28
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 28 Feb 15
Sunspots AR2293 and AR2294 are growing rapidly and could soon pose a threat for solar flares. Credit: SDO/HMI

Sunspot number: 58
What is the sunspot number?
Updated 28 Feb 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%)

Update 28 Feb 2015

The Radio Sun
10.7 cm flux: 118 sfu
explanation | more data
Updated 28 Feb 2015

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/Ovation
Planetary K-index
Now: Kp= 3 quiet
24-hr max: Kp= 4
explanation | more data
Interplanetary Mag. Field
Btotal: 10.0 nT
Bz: 9.4 nT south
explanation | more data
Updated: Today at 2352 UT
Coronal Holes: 28 Feb 15
A Solar wind flowing from this southern coronal hole should reach Earth on Feb. 28-March 2. Credit: SDO/AIA.
Noctilucent Clouds The southern season for NLCs has come to an end. The last clouds were observed by NASA's AIM spacecraft on Feb. 20, 2015. Now attention shifts to the northern hemisphere, where the first clouds of 2015 should appear in mid-May.
Switch view: Ross Ice Shelf, Antarctic Penninsula, East Antarctica, Polar
Updated at: 02-28-2015 02:55:03
NOAA Forecasts
Updated at: 2015 Feb 28 2200 UTC
0-24 hr
24-48 hr
10 %
10 %
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 Feb 28 2200 UTC
0-24 hr
24-48 hr
40 %
40 %
25 %
25 %
05 %
05 %
High latitudes
0-24 hr
24-48 hr
10 %
10 %
25 %
25 %
60 %
60 %
Saturday, Feb. 28, 2015
What's up in space

Come to Tromsø and share Marianne's passion for rural photography: invites you to experience "Heaven on Earth" with an aurora, fjord, fishing, whale watching, photography or sightseeing tour.

Chase the Light Tours

CHANCE OF STORMS: Earth is about to pass through a fold in the heliospheric current sheet. Waiting on the other side is a high-speed solar wind stream that could spark auroras when it makes contact with Earth. NOAA forecasters estimate a 60% chance of polar geomagnetic storms this weekend. Aurora alerts: text, voice

NOCTILUCENT CLOUDS, BEHAVING STRANGELY: The southern season for noctilucent clouds (NLCs) has come to an end. NASA's AIM spacecraft observed the last wisps of electric-blue over Antarctica on Feb. 20, 2015. The end of the season was no surprise: The polar clouds always subside in late summer. Looking back over the entire season, however, reveals something unexpected. In an 8-year plot of Antarctic noctilucent cloud frequencies, the 2014-2015 season is clearly different from the rest:

These data come from the AIM spacecraft, which was launched in 2007 to monitor NLCs from Earth orbit. The curves show the abundance ("frequency") of the clouds vs. time for 120 days around every southern summer solstice for the past 8 years.

"This past season was not like the others," notes Cora Randall, a member of the AIM science team and the chair of the Department of Atmospheric and Oceanic Sciences at the University of Colorado. "The clouds were much more variable, and there was an enormous decrease in cloud frequency 15 to 25 days after the summer solstice. That's when the clouds are usually most abundant."

What does this mean? Previous research shows that NLCs are a sensitive indicator of long-range teleconnections in Earth's atmosphere, which link weather and climate across hemispheres. The strange behavior of noctilucent clouds in 2014-2015 could be a sign of previously unknown linkages. "Preliminary indications are that it is indeed due to inter-hemispheric teleconnections," says Randall. "We're still analyzing the data, so stay tuned."

Now attention turns to the northern hemisphere, where the season for NLCs typically begins in May. Will the northern season ahead be as strangely variable as the southern season, just concluded? Says Randall, "I can't wait to find out."

Boosting the chances of auroras even more is a high-speed solar wind stream waiting on the other side of the heliospheric current sheet. The wind is flowing from a coronal hole on the sun, shown in this extreme UV image from NASA's Solar Dynamics Observatory:

Coronal holes are places in the sun's atmosphere where the sun's magnetic field opens up, allowing hot gas to escape. In the image, above, the magnetic field is traced by curved white lines. Arrows show where the solar wind is escaping along open field lines. Forecasters expect the gassy stream to reach Earth on Feb. 28-March 1. Keep an eye on the realtime photo gallery for aurora sightings this weekend.

Realtime Aurora Photo Gallery

WHAT ARE THE ODDS? On Feb.19th, and the students of Earth to Sky Calculus launched a helium balloon to the stratosphere. The payload, a cosmic radiation buoy, traveled 112,300 feet above Earth's surface and drifted more than 85 linear miles from the launch site. When it parachuted back to Earth, it landed in a sparsely vegetated stretch of Nevada desert. Getting caught in a tree would seem unlikely, yet that's exactly what happened:

The payload descended into a beautiful forest of Joshua trees, and one of them snagged the parachute. As the student recovery team learned, disentangling the cords of a parachute from the spikey embrace of a Joshua tree is no easy trick. Nevertheless, they persisted and won back their radiation buoy.

The students have been flying radiation buoys to the stratosphere since 2013. Their purpose is to monitor the effect of cosmic rays and solar activity on the upper atmosphere. This buoy carried a pair of ionizing radiation detectors, sensitive to X-rays, gamma-rays and beta particles in the energy range 10 keV to 20 MeV.

A preliminary look at the Feb. 19th data reveals some of the highest radiation levels recorded in the 2-year history of the program. This could be a result of the current spate of low solar activity. Cosmic rays are repelled by CMEs and strong solar magnetic fields. When the sun is quiet, cosmic rays penetrate the solar system in greater numbers--an effect which the students are monitoring with their balloon flights.

Realtime Space Weather Photo Gallery

Realtime Comet 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 Feb. 28, 2015, the network reported 7 fireballs.
(7 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 February 28, 2015 there were potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
2015 DF200
Feb 23
3.7 LD
26 m
2015 DU
Feb 23
8 LD
20 m
2015 CA40
Feb 23
6.3 LD
51 m
2000 EE14
Feb 27
72.5 LD
1.6 km
2015 DY198
Mar 1
2.2 LD
21 m
2015 DS53
Mar 2
3.1 LD
63 m
2015 DK200
Mar 8
6.9 LD
34 m
2063 Bacchus
Apr 7
76 LD
1.6 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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