SAN FRANCISCO - Researchers using NASA's twin Mars rovers are sorting
out two possible origins for one of Spirit's most important discoveries,
while also getting Spirit to a favorable spot for surviving the next
The puzzle is what produced a patch of nearly pure silica -- the main
ingredient of window glass -- that Spirit found last May. It could have
come from either a hot-spring environment or an environment called a
fumarole, in which acidic steam rises through cracks. On Earth, both of
these types of settings teem with microbial life.
"Whichever of those conditions produced it, this concentration of silica
is probably the most significant discovery by Spirit for revealing a
habitable niche that existed on Mars in the past," said Steve Squyres of
Cornell University, Ithaca, N.Y., principal investigator for the rovers'
science payload. "The evidence is pointing most strongly toward
fumarolic conditions, like you might see in Hawaii and in Iceland.
Compared with deposits formed at hot springs, we know less about how
well fumarolic deposits can preserve microbial fossils. That's something
needing more study here on Earth."
Is it just me, or does it seem that every week a new discovery and/or interpretation of Mars rules out the possibility of the planet ever having been warm and wet, only to be followed a week later by additional data that suggests the place was lousy with water? Olivine, hematite... each study contradicts the next, apparently. What do you want to bet that when all is said and done, these disparate pockets of observations and evidence all turn out to be correct in some manner of speaking?