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. | | |
DAWN'S SMOOTH MOVE: NASA's ion-propelled Dawn spacecraft entered orbit around Vesta last month in an unusual way. Today's story from Science@NASA explains Dawn's smooth move and unveils the first full-frame image of the giant asteroid. Click here.
EARTH-DIRECTED BLAST: Magnetic fields above sunspot 1261 erupted this morning at 0619 UT, producing a long-duration M1-class solar flare. At the peak of the action, NASA's Solar Dynamics Observatory recorded a surge of extreme ultraviolet radiation around the sunspot:
The blast also hurled a coronal mass ejection (CME) almost directly toward Earth. Space-based coronagraph images from SOHO and from STEREO-A show the cloud racing away from the sun at almost 900 km/s. Minor to moderate geomagnetic storms are possible when the CME arrives on or about August 5th. Aurora alerts: text, voice.
July 2011 Aurora Gallery
[previous Julys: 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003]
MAGNIFICENT SUNSPOT: Double sunspot 1263 is a whopper. Its two dark cores are each wider than Earth, and the entire region stretches more than 65,000 km from end to end. Yesterday in the Netherlands, Emil Kraaikamp took advantage of a break in the clouds and "a few moments of steady air" to capture this magnificent photo:
"To image this monster, I used a 10-inch Newtonian telescope capped by a white light solar filter," says Kraaikamp. He used the same setup to photograph nearby sunspot 1261. The clarity of both images is impressive. Note the granulation of the stellar surface surrounding the main dark cores. Those are Texas-sized bubbles of plasma rising and falling like water boiling on top of a hot stove.
The magnetic field of sunspot 1263 harbors energy for powerful X-class solar flares. Because the sunspot is turning to face Earth, any such eruptions in the days ahead would likely be geo-effective. Solar flare alerts: text, voice.
TODAY'S BONUS SHOTS: Lightning Spectrum from Marsha Adams of Sedona, Arizona; Sunspot Sunset from Hossein Haeri-Ardakani of Ardakan, Yazd, Iran
2011 Noctilucent Cloud Gallery
[previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009]
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 August 2, 2011 there were 1241 potentially hazardous asteroids.
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. | The official U.S. government space weather bureau |
| The first place to look for information about sundogs, pillars, rainbows and related phenomena. |
| 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 |
| Realtime and archival images of the Sun from SOHO. |
| from the NOAA Space Environment Center |
| the underlying science of space weather |
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