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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Solar wind
speed: 659.9 km/sec
density: 0.1 protons/cm3
explanation | more data
Updated: Today at 2346 UT
X-ray Solar Flares
6-hr max: M1
2039 UT Mar17
24-hr: M1
2039 UT Mar17
explanation | more data
Updated: Today at: 2300 UT
Daily Sun: 17 Mar 12
Solar activity is dropping now that big sunspot AR1429 has rotated off the Earth-facing side of the sun. Credit: SDO/HMI
Sunspot number: 104
What is the sunspot number?
Updated 16 Mar 2012

Spotless Days
Current Stretch: 0 days
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

Updated 16 Mar 2012

The Radio Sun
10.7 cm flux: 99 sfu
explanation | more data
Updated 16 Mar 2012

Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Planetary K-index
Now: Kp= 4 unsettled
24-hr max: Kp= 4
explanation | more data
Interplanetary Mag. Field
Btotal: 4.1 nT
Bz: 3.7 nT south
explanation | more data
Updated: Today at 2342 UT
Coronal Holes: 17 Mar 12
Earth is entering a solar wind stream flowing from this coronal hole. Credit: SDO/AIA.
NOAA Forecasts
Updated at: 2012 Mar 17 2200 UTC
0-24 hr
24-48 hr
30 %
30 %
05 %
05 %
Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at: 2012 Mar 17 2200 UTC
0-24 hr
24-48 hr
40 %
30 %
20 %
15 %
05 %
01 %
High latitudes
0-24 hr
24-48 hr
15 %
15 %
25 %
20 %
35 %
25 %
Saturday, Mar. 17, 2012
What's up in space

Metallic photos of the sun by renowned photographer Greg Piepol bring together the best of art and science. Buy one or a whole set. They make a stellar gift.

Metallic pictures of the Sun

GREEN SKIES FOR ST. PATRICK'S DAY? NOAA forecasters estimate a 20% chance of geomagnetic storms around the poles on March 17th in response to a high-speed solar wind stream buffeting Earth's magnetic field. Northern Lights could descend all the way down to Ireland, concluding St. Patrick's Day with a flourish of heavenly green. Aurora alerts: text, phone.

Just outside Edmonton, Alberta, photographer Zoltan Kenwell started celebrating a day early when this display appeared on March 16th:

"I have never seen the auroras dance so quickly before. It was an unbelievable show," says Kenwell. "The view looking straight up was incredible. I laid down in the middle of a field and just watched in total amazement. Here is a time-lapse movie."

more images: from Shawn Malone of Marquette, Michigan; from Thomas Achermann of Muonio, Finnish Lapland; from Ruslan Ahmetsafin of Aykhal, Yakutia, Russia; from Jaromir Stanczyk of Iceland; from Rich Stromberg near Anthracite Ridge, Alaska; from Andrei Penescu of Kangerlussuaq, Greenland; from Matt Moffet of Bozeman, Montana; from Nate Deppe of Virginia, MN; from Iurie Belegurschi of ├×ingvellir National Park, Iceland; from Brian Whittaker flying 36,000 feet over Greenland; from Travis Novitsky of Grand Portage, MN; from Lance Parrish of Skiland, Alaska;

SCINTILLATION SQUIGGLES: Everyone knows that stars twinkle but planets do not. The reason has to do with angular size. Stars are distant pinpricks smaller than the thermal irregularities in Earth's atmosphere that refract their light. Each packet of air that passes in front of a star produces a well-defined change in color or brightness. Planets, on the other hand, are relatively nearby and wide; they span many atmospheric irregularities, which tends to smooth out the prismatic action.

Photographer Monika Landy-Gyebnar of Veszprem, Hungary, has found a kinetic way to demonstrate the effect. "When photographing a star or planet, kick the tripod during the exposure." She's applied this technique to many stars and planets, and the resulting collection of squiggles reveals the character of their twinkles:

"If we take a photo of a star with a shaking camera, the result is a wavy line with many colors," she points out. "If we photograph a planet, however, there is no change; the color and width of the squiggle are nearly constant."

The scintillation effect is greatest for stars near the horizon, which must shine through a greater distance of turbulent atmosphere. Angles noted in the image above are altitudes. The lowest-hanging stars display the strongest and most colorful twinkling.

"Demonstrating this is a 'must-do' thing when you give a lecture or show on astronomical observations for novices," she concludes. Observing tips and more of Landy-Gyebnar's "scintillation squiggles" may be found here.

February 2012 Aurora Gallery
[previous Februaries: 2011, 2010, 2009, 2008, 2007, 2006, 2004, 2003, 2002]

  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 March 17, 2012 there were 1287 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Miss Distance
1999 RD32
Mar 14
57.9 LD
2.4 km
2012 FG
Mar 14
1.6 LD
26 m
2012 EN5
Mar 15
1.4 LD
15 m
2012 EL8
Mar 16
7.3 LD
10 m
2011 YU62
Mar 16
73.4 LD
1.3 km
2012 EO8
Mar 21
3.6 LD
58 m
2012 EK5
Mar 22
5.8 LD
33 m
2012 EG5
Apr 1
0.6 LD
62 m
1996 SK
Apr 18
67.2 LD
1.6 km
2007 HV4
Apr 19
4.8 LD
8 m
2011 WV134
Apr 28
38.6 LD
1.6 km
1992 JD
May 2
9.5 LD
43 m
2010 KK37
May 19
2.3 LD
31 m
4183 Cuno
May 20
47.4 LD
5.7 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
Trade Show Displays
  more links...
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