Asteroid comes close to Earth Tuesday 11/8/11 - no expected threat

From  CNN 11/3/11, includes embedded video (1 minute).  "An aircraft carrier-sized asteroid, a little over four football fields in diameter, is heading toward Earth and it will pass closer to our planet than the moon.  NASA has classified the asteroid as a “potentially hazardous object” and it will pass to within .8 lunar distances on November 8.  It is the closest approach to Earth of an object this size in over 30 years.

What would happen if an asteroid this size crashed into Earth?  It would result in a 4,000 megaton blast, magnitude 7.0 earthquake and - if it falls into the ocean - could cause a 70-foot high tsunami within 60 miles of the crash site, according to an expert at Purdue University.  However, this space rock poses no threat of an Earth collision for at least the next 100 years, according to NASA’s Near Earth Object Program.

So what’s the big deal?  Encounters of objects this large this close to our planet won't happen again until the year 2028 when an asteroid will pass near Earth to within .6 lunar distances.  NASA plans to study the asteroid with the Goldstone radar antennas in California’s Mojave Desert. Goldstone antennas are very sensitive radio telescopes used to investigate quasars, radar mapping of planets and comets.  Scientists plan to reconstruct the shape of the asteroid with a resolution as fine as 13 feet (4 meters) using the antennas. Several days of high resolution operations are also scheduled at the Arecibo Observatory in Puerto Rico.

It will also provide a rare opportunity for amateur astronomers to directly observe an asteroid with optical telescopes.  The asteroid will approach Earth from a sunward direction and it will be a daylight object until the time of its closest approach on November 8.  The best time to see the asteroid will be after the hours of 4 pm EST (21:00 UTC)."

Separate article from SF Gate, 11/5/11.

Posted by Kathy Meeh