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

[MexicoDoug 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.