Are we alone? Your iPhone has the answer. Download the all-new Drake Equation app to calculate the population of the Milky Way.
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SO MUCH FOR DOOMSDAY: Comet Elenin (C/2010 X1), widely known for inaccurate reports of its threat to Earth, appears to be breaking apart. Observations by amateur astronomer Michael Mattiazzo of Castlemaine, Australia show a marked dimming and elongation of the comet's nucleus over a ten day period:
The behavior of Comet Elenin is akin to that of Comet LINEAR (C/1999 S4), which disintegrated when it approached the sun in back in 2000. Mattiazzo witnessed that event, too. "Yes I did observe the breakup of C/1999 S4 in July 2000," he recalls. "It was quite spectacular watching the nucleus spread out into a cigar shape over a period of days. The apparent breakup of C/2010 X1 is similar, although less visually spectacular."
Comets are fragile objects, easily disrupted by solar heat. As a result, the possible breakup of Comet Elenin, while unexpected, comes as no surprise. Readers with pertinent images are invited to submit them here.
CHANCE OF AURORAS: NOAA forecasters estimate a 20% chance of polar geomagnetic activity tonight in response to a solar wind stream gently buffeting Earth's magnetic field. Arctic sky watchers should be alert for auroras.
Lance Parrish of Skiland, Alaska, photographed this display just after midnight on August 29th:
"Note the hint of sunset in the background," notes Parrish. "As summer winds down the midnight sun is retreating, allowing us to see Northern Lights again."
Teenage photographer Brandon Lovett, who just turned 18, witnessed the same display about 20 miles away in Fairbanks. "It was unbelievable! [The sky] burst into a colorful dancing display of green, white, pink, purple, and much more. These photos have not been re-touched; they are straight out of the camera."
August 2011 Aurora Gallery
[previous Augusts: 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002]
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 30, 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.
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| ||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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