[meteorite-list] Mars Rover's Meteorite Discovery Triggers Questions

From: MexicoDoug_at_aol.com <MexicoDoug_at_meteoritecentral.com>
Date: Fri Jan 21 13:39:56 2005
Message-ID: <e1.b42532d.2f22a673_at_aol.com>

Hola Beda, List,

Good points. Also to consider is that "Heat Shield Rock", a piece of
nickel-iron steel weighs "in weight", just slightly more than quartz does on Earth,
the equivalent of about 2.9 g/cc density for comparison. So the 50 kg is the
equivalent mg' of 18.8 kg - but still with the tensile strength of steel to
maintain cohesivity upon impact. (More mass for the money on Mars for
curators and collectors) That is less gravitational weight than most equivalent
STONY metetorites sizes on Earth, less than typical basalts, due to the Martian
gravity. This, to some appreciable extent offsets for the thin ~1% Martian
(vs. Earth) atmosphere. A 1 km/sec (2237 mph) velocity should be survivable
for a decent sized iron, though another point to bring up is that meteorites
landing on Mars would all exhibit higher shock levels, especially veining,
fractures in olivines, etc... And the entry angle as mentioned of course would
be more important, as well as shield vs. aerodynamic nosecone shaping...
The Martian soil looks like a softer landing than the Sahara sands...
Saludos, Doug
PS On Earth, ~50 kg Cabin Creek probably fell at ~300 mph (134 km/hr), while
a nosecone would be up to the ~700 mph range (312km/hr).

En un mensaje con fecha 01/21/2005 9:55:49 AM Mexico Standard Time,
beda.hofmann_at_nmbe.unibe.ch escribe:

>The first meteorite found on Mars - "Heat shield rock" - really
>raises questions. Based on its size I estimate it is approx. 6-7
>liters in volume or around 50 kg mass.
 
Received on Fri 21 Jan 2005 01:39:47 PM PST