This blog provides commentary on interesting geological events occurring around the world in the context of my own work. This work is, broadly, geological fluid dynamics. The events that I highlight here are those that resonate with my professional life and ideas, and my goal is to interpret them in the context of ideas I've developed in my research. The blog does not represent any particular research agenda. It is written on a personal basis and does not seek to represent the University of Illinois, where I am a professor of geology and physics. Enjoy Geology in Motion! I would be glad to be alerted to geologic events of interest to post here! I hope that this blog can provide current event materials that will make geology come alive.

Banner image is by Ludie Cochrane..

Susan Kieffer can be contacted at s1kieffer at gmail.com

Tuesday, November 8, 2011

Asteroid 2005 YU55 is NOT Armageddon!

Radar image of 2005 YU55 in April 2010
Armageddon was a 1998 thriller movie based on a Texas-sized asteroid heading toward the earth, which would then be saved by Holllywood heros sent to nuke the rock (which would simply create a lot of smaller destructive asteroids still headed toward us! Asteroid 2005 YU55 is not as big as Texas, only the size of an aircraft carrier (400 m diameter), and it's heading for closest approach tonight (Tuesday, November 8th at 23:28 UT (5:28 CDT). It will come inside the orbit of the Moon, about 85% of the distance between the Earth and Moon. The asteroid was discovered at the University of Arizona's Lunar and Planetary Laboratory on December 28, 2005. Objects this size come by about every 30 years.

According to Jay Melosh at Purdue, the asteroid would create a crater 6.3 km across, 518 m deep, and deposit the energy equivalent to a magnitude 7 eartquake. YU will pass close to Venus in 2029 and the exact details of that encounter will determine how close to the earth it will come in 2041.

JPL has a small-body database browser here that allows you to visualize the orbit, but the site is, at this time a few hours before the encounter, overloaded. We're not going to see it in gray, rainy Urbana tonight, but amateur observers in Europe and on the East Coast have a great chance. This is the first near asteroid for which observers have had advance warning and been gearing up to make radar, visual and infrared observations. With 5-meter radar observation, they are hoping to create a detailed 3-D image of its shape and surface.

I'll update the photos as they are released after the encounter.

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