[BR-Crater] Mars impact odds down to 1:40

[Ian Kluft]

As expected, astronomers have been updating the estimated impact odds for
Mars with new observations and newly-recognized historic observations.
Tuesday the latest update dropped the odds to 1 in 40.

   "Mars Impact Seems Less Likely"
   http://neo.jpl.nasa.gov/news/news155.html

   "Good news for Mars! Asteroid risk fades"
   http://www.msnbc.msn.com/id/22562747/

There was an update last week which dropped it from 1:25 to 1:28.  I didn't
send that along since it was a very small change.  Anywhere you're seeing
either of those numbers still in the news, they have old data.

Remember this started at 1 in 75.  As long as the chance doesn't drop to
zero, the possible Mars-crossing path could include an impact.  But the
odds are still against it, currently a 39 out of 40 chance it will miss.