Tuesday, December 11, 2012


GEMINID METEOR SHOWER--THIS WEEK! The annual Geminid Meteor Shower is set to peak on Dec. 13 and 14, 2012. The display, which is caused by an unusual 'rock comet,' could produce more than 100 meteors per hour during the dark hours before dawn this Thursday and Friday.


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ASTEROID FLYBY: Newly-discovered asteroid [emphasis mine] 2012 XE54 is flying through the Earth-Moon system today approximately 230 thousand km (0.6 LD) from Earth. The space rock is about 36 meters wide, a little smaller than the Tunguska impactor that leveled 800 square miles of Siberian forest in 1908. Using a remote-controlled telescope in New Mexico, astronomers Ernesto Guido and Nick Howes photographed 2012 XE54 streaking among the stars on Dec. 11th:

Guido and Howes dedicate this image to the memory of their longtime friend and colleague Giovanni Sostero.

This asteroid will not hit Earth, but it is close enough, and thus bright enough, for amateur astronomers to track using backyard telescopes. When Guido and Howes photographed it this morning, it was shining at magnitude +13.

Astronomers monitoring the asteroid might have noticed an unusual eclipse during the early hours of Dec. 11th. According to calculations made by P. Tricarico, 2012 XE54 "will likely cross the Earth's shadow, causing a partial eclipse of the asteroid a few hours before reaching its minimum distance with the Earth. Asteroids eclipsing during an Earth flyby are relatively rare, with the first known case of asteroid 2008 TC3 which was totally eclipsed just one hour before entering Earth's atmosphere over Sudan in 2008, and asteroid 2012 KT42 experiencing both an eclipse and a transit during the same Earth flyby in 2012."

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The solar flare of 774 AD

Working backwards from the intensity required to produce the right amount of carbon-14 in Earth's atmosphere, they mistakenly calculated the total size of the event ... Still, it leaves it some 20 times larger than the 1859 Carrington Event—the largest solar flare recorded from the Sun. Events that large have been observed on other stars, so it's possible our Sun is capable of it, as well.

Scott Johnson at arstechnica.com
h/t: Ol' Remus at http://www.woodpilereport.com/