[ExI] Asteroid on track for possible (updated probability of 1:28) Mars hit

[Amara Graps]

Kevin H kevin.l.holmes at gmail.com :
>I wasn't aware of SPICE before and this discovery of 2007 WD5 has
>brought a resurge in interest in astronomy for me, specifically what I
>think you'd call celestrial mechanics or solar system dynamics.  For
>instance, it still astounds me how they can predict that Apophis will
>get *so* close to the Earth, and yet miss it when it swings by in 2029
>as well as miss the gravitational "keyhole" that will put it at risk in
>2036.  It just amazes me the accuracy of these predictions (although, of
>course, the flyby hasn't happened yet).

I'm blown away that the dust trails that are sloughed off by the parent
comets to become the meteor streams, which the Earth intersects in times
of meteor showers are predicted so accurately. So that the scientists
can distinguish trails from particular past years of the comet's passage
going back a few hundred years.

For example:
http://www.arm.ac.uk/leonid/dustexpl.html
http://www.arm.ac.uk/leonid/

If you are curious why I'm blown away by such accurate predictions, it is
because gravity isn't the only force impressed on the particles.

Amara

-- 

Amara Graps, PhD      www.amara.com
Research Scientist, Southwest Research Institute (SwRI), Boulder, Colorado