What is the "escspe velocity" for an object leaving Mars? Because I still have a problem with ALH84001 leaving
the planet without some kinda propulsion other than the impact of a "huge" asteroid/comet? impact propelling it.
The matter of it revolving around the sun for eons before "picking" Antarctica for a resting place still is puzzling for me.
(I know, I've already read about its' constituancy is the same as a "Mars rock", but is it not possible that it may just possibly have come from the asteroid belt???)
- 1 decade agoFavorite Answer
The escape velocity for an object leaving the surface of Mars is approximately 5.0 km/s. This is extremely easy to come by through an asteroidal collision - ejecta can be sprayed from impact craters at many orders of magnitude faster than this. For reference and comparison, the escape velocity from the surface of the earth is 11.2 km/s.