Life On Mars..? (I'm not making this up, honestly...) (off topic)

[Le Monsieur]

On Tue, 6 Aug 1996, Andy Gilham wrote:
> Damon asks
> >Um, scuse me for asking, but how does a piece of Mars remove itself from
> >the planet and hurl itself into space toward Earth?
> Sodding great meteorite hits Mars, bits fly everywhere, end up all over the
> oche.  Simple as that!
That's what I figured.  Now, I have a few more questions, then.  Yes,
I'm being very skeptical, but then again I'm not an astrogeologist.

1) Someone finds a meteorite.  I'll accept a scientist's ability to tell
a meteorite from some other rock.  "Look, a big hole in the ground!  And
a rock right in the middle of it! [scratches chin]"  But then another
scientist must've looked at it and said, "Oh, it must come from Mars.
*Everything* comes from Mars."  Seriously, though, of all the places this
rock could've come from, how in the world does a person figure it out
exactly?

2) Possible answer:  chemical makeup.  OK.  The rocks on Mars are (I
could be wrong on this) about 95% iron oxide and 5% other stuff, right?
Well, most asteroids are made of the same stuff, except it's iron instead
of iron oxide.  Well, when a big chunk of iron sits in the great outdoors
(or indoors, for that matter) for 100,000 years (is that the figure?), it
tends to, um, oxidize.  And meanwhile, couldn't bacteria have grown on
the rock sometime between now and then?

Damon Capehart        | "I think we should eliminate semicolons from the
aka Le Monsieur       |  English language; nobody uses them anymore
dcapehar at utdallas.edu |  anyway." - one of Dilbert's anonymous coworkers