The Evolutionary Biology Lecture of the Week for June 26, 2006 is now available
at:

http://aics-research.com/lotw/

The talks center primarily around evolutionary biology, in all of its aspects:
cosmology, astronomy, planetology, geology, astrobiology, ecology, ethology,
biogeography, phylogenetics and evolutionary biology itself, and are presented
at a professional level, that of one scientist talking to another. All of the
talks were recorded live at conferences.

This is the sixth lecture in a summer-long series on the new science of
astrobiology.

=====================================

July 3, 2006

Part VII: Astrobiology

The MER Mission and the Stratigraphic History of the Meridiani Planum

Steven Squyres, Cornell University

34 min.

"If Mars be capable of supporting life, there must be water upon his surface;
for, to all forms of life, water is as vital a matter as air. On the question
of habitability, therefore, it becomes all-important to know whether there be
water on Mars."

— Percival Lowell, 1895

A "sol" is a Martian day, which by chance is very nearly the same length as an
Earth day, 24 hrs 40 min. The Spirit and Opportunity rovers were sent to Mars
to be the robotic hands and eyes of geologists left on Earth to out seek
evidence for ancient water. But Mars is a challenging environment. The rovers
were only "warrantied" to work for 90 sols, but against all odds they've
continued to function far beyond their original expectations, having just now
passed the 900 sol mark.

Steven Squyres, the principal investigator for the rovers, was informally
interviewed on CNN last week and was asked how things were going. He said,
"We're very tired. Very happy, but very tired."

The Spirit Rover, as described by Matt Golombek in last week's lecture, landed
on the floor of Gusev Crater, which was found to have been dry and dessicating
since the late Hesperian (approximately 3.5 billion years).

Opportunity was sent to the other side of Mars, into the lowlands at Meridiani
Planum. The intention of both rovers was to seek out evidence of ancient water.
While Gusev was discovered to have been dry for at least three-quarters of
Mars' existence, Meridiani gives every evidence to have been once deep in
water.