[meteorite-list] Mars Impact Seems Less Likely (Asteroid 2007 WD5)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 8 Jan 2008 13:33:26 -0800 (PST)
Message-ID: <200801082133.NAA04348_at_zagami.jpl.nasa.gov>

http://neo.jpl.nasa.gov/news/news155.html

Mars Impact Seems Less Likely
Steve Chesley, Paul Chodas and Don Yeomans
NASA/JPL Near-Earth Object Program Office
January 8, 2008

We have updated the orbit of 2007 WD5 using new observations from the
3.5-meter telescope at the Calar Alto Observatory in Spain. This update
also incorporates refinements to the Sloan precovery observations
mentioned previously. While the best estimate of close approach distance
remains steady at about 30,000 km, the uncertainty in position at the
close approach has decreased by a factor of three. As a result, the
impact probability estimate has fallen to 2.5%, or 1-in-40 odds. If the
estimated miss distance remains stable in future updates, the impact
probability will continue to fall as continuing observations further
constrain the uncertainties.

[Graphic]
Updated Uncertainty Region for 2007 WD5 at encounter with Mars, shown as
white dots. The thin white line is the orbit of Mars. The blue line
traces the motion of the center of the uncertainty region, which is the
most likely position of the asteroid.
Received on Tue 08 Jan 2008 04:33:26 PM PST