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Re: Dinosaurs in space?
In a message dated 5/17/01 3:17:36 PM EST, email@example.com writes:
<< The most likely planets with Earth rocks would therefore be Venus and
Mercury, but their extreme environments aren't very conducive to rocks lying
around unchanged like they would on the Moon (which also has the advantage
of being so close to us). >>
It is much more difficult to reach Mercury than Mars via meteorite from
earth. Mercury is deep within the sun's gravitational well, and a meteorite
would have to lose quite a bit of the earth's orbital velocity in order to
reach that planet, considerably more than would have to be added to earth's
velocity to reach Mars. Spacecraft from earth to Mercury (e.g., Mariner 10)
have to use Venus for precise gravity-assisted slowdown to accomplish this,
but random meteorites from earth would be much more likely to simply hit
Venus than to be slowed down enough to go all the way to Mercury.