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CHANCE OF FLARES: Sunspot AR1465 has developed a 'beta-gamma-delta' magnetic field that harbors energy for strong flares. NOAA forecasters estimate a 20% chance of M-class eruptions during the next 24 hours. Because the active region is located on the Earthside of the sun, any flares from AR1465 will likely be geoeffective.
Even without a strong eruption from AR1465, ionization waves are already rippling through Earth's upper atmosphere. Dave Gradwell of Birr, Ireland, recorded a series of sudden ionospheric disturbances (SIDs) on April 27th:
Low-level flares from several sunspot groups (especially 1465, 1466 and 1467) are strobing the atmosphere with ionizing radiation. Using a VLF receiver, Gradwell detected their effect on the propagation of radio signals transmitted from France. So far the disturbances have been relatively weak, but this could change if AR1465 unleashes a more potent eruption over the weekend. Solar flare alerts: text, phone.
FIREBALL PHOTOS WANTED: Meteor expert Peter Jenniskens of NASA's Ames Research Center could use some help from the general public--in particular, photographers and business owners with security cameras in central California. He needs photos of the mini-van sized asteroid that exploded over the region on Sunday morning, April 22nd, at 7:51 am PDT. "Our goal is to determine the orbit of the object and to understand how this small asteroid fell apart when it entered the earth's atmosphere," he explains. [Got photos? Submit them here.]
Meteorite hunters, Jenniskens included, are starting to find pieces of the asteroid on the the ground. These samples were lying in the parking lot of Henningsen-Lotus Park, apparently crushed by a passing car:
The meteorites landed not far from Sutter's Mill in El Dorado County, CA, the same place gold was discovered in the 19th century, triggering the California Gold Rush. Jenniskens likens the thrill of finding these space rocks to finding gold: " I think John A. Sutter must have felt the same way when he found the first gold nugget back in January of 1848."
"The meteorites appear to be CM chondrites," he continues. This would make the sample very primitive, possibly contiaining minerals and compounds preserved from a time when the solar system was very young. "I can not say more as the samples have not yet been analyzed. My main concern now is to recover perishable data of the fireball, such as video security camera footage."
More footage will help researchers answer questions like these: "Was this a rubble pile or a monolitihic block? Was the orbit very evolved, or could its semi-major axis perhaps still point us to the source region of CM chondrites in the asteroid belt?" Jeniskens wonders. "This is a rare opportunity to learn about the properties of a particular class of near-Earth objects."
News reports: #1, #2, #3.