[meteorite-list] No soft landings

From: Matson, Robert <ROBERT.D.MATSON_at_meteoritecentral.com>
Date: Thu Apr 22 09:52:09 2004
Message-ID: <AF564D2B9D91D411B9FE00508BF1C86901B4E2AF_at_US-Torrance.mail.saic.com>

Hi Chris,

> I have a question for the list:

> Is it possible that a large body with cosmic velocity could have a
> "soft touchdown" on Earth?

Nope.

> ie not come in 25km/s and be explosively disintegrated by the enormous
> kinetic energy that comes with such a large, high speed mass. I could
> imagine a situation where the relative velocities between an impactor
> and the Earth were <1 km/s so long as the impactor approached on the
> same track as the Earth's orbit around the sun.

The thing you are neglecting is the earth's gravitational field --
this will accelerate any body (slowly catching up with earth from
behind, for instance) to at least the escape velocity of earth.

Cheers,
Rob
Received on Thu 08 Aug 2002 06:50:56 PM PDT