Green Mineral Indicates Mars Is Dry

Marc 182 wrote in message et...


Also, does the presence of olivine rule out permafrost, or other
sequestered water, right below it?


Probably not. Interstellar olivine and olivine in comet
Hale-Bopp are surrounded by ice.
http://www.esa.int/export/esaCP/Pr_10_1997_i_EN.html
John Curtis

In article ,
John Curtis wrote:
Also, does the presence of olivine rule out permafrost, or other
sequestered water, right below it?

Probably not. Interstellar olivine and olivine in comet
Hale-Bopp are surrounded by ice.

That's stuff that's been in a cryogenic deep-freeze essentially forever.
By comparison, the surface of Mars is pretty warm, and the rules are
not the same.
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |

I wrote:
...That Hawaiian
beach is geologically very young (as is everything on the Big Island).

A minor postscript on this... I finally dug down to the issue of Science
with the paper on the Mars olivine, and interestingly enough, some samples
of "Hawaiian green sand beach olivine" are among his calibration references.
--
MOST launched 30 June; first light, 29 July; 5arcsec | Henry Spencer
pointing, 10 Sept; first science, early Oct; all well. |