SAN FRANCISCO (Reuters) - Scientists have found
evidence of an ancient freshwater lake on Mars well
suited to support microbial life, the researchers said
Monday.
The lake, located inside Gale Crater where the rover
landed in August 2012, likely covered an area 31
miles long and 3 miles wide, though its size varied
over time.
Analysis of sedimentary deposits gathered by NASA's
Mars rover Curiosity shows the lake existed for at
least tens of thousands of years, and possibly longer,
geologist John Grotzinger, with the California
Institute of Technology in Pasadena, told reporters at
the American Geophysical Union conference in San
Francisco.
"We've come to appreciate that is a habitable system
of environments that includes the lake, the associated
streams and, at times when the lake was dry, the
groundwater," he said.
Analysis of clays drilled out from two rock samples in
the area known as Yellowknife Bay show the
freshwater lake existed at a time when other parts of
Mars were dried up or dotted with shallow, acidic,
salty pools ill-suited for life.
In contrast, the lake in Gale Crater could have
supported a simple class of rock-eating microbes,
known as chemolithoautotrophs, which on Earth are
commonly found in caves and hydrothermal vents on
the ocean floor, Grotzinger said.
Scientists also reported that the clays, which form in
the presence of water, were younger than expected,
a finding that expands the window of time for when
Mars may have been suited for life.
Previous studies from Mars orbiters, landers and
rovers have provided increasing evidence for a
warmer, wetter, more Earth-like Mars in the planet's
past. Ancient rocks bear telltale chemical fingerprints
of past interactions with water.
The planet's surface is riddled with geologic features
carved by water, such as channels, dried up
riverbeds, lake deltas and other sedimentary
deposits.
New related studies on how much radiation blasts the
planet set new boundaries for how long any organic
carbon, which so far has not been found on Mars,
could have been preserved inside rocks within about
2 inches of the surface, the depth of Curiosity's drill.
But finding rock samples with relatively short
exposure times should not be a problem. An age-
dating technique, used for the first time on Mars,
reveals that winds are sand-blasting away the rock
faces at Gale Crater.
One of the mudstones at Yellowknife Bay, for
example, has been exposed to the destructive effects
of cosmic rays for only about 70 million years, well
within the period of time to detect organics, said Don
Hassler with the Southwest Research Institute in
Boulder, Colorado.
The Yellowknife Bay samples also showed hints of
possible organics that may have been destroyed in
the rover's laboratory oven due to highly oxidizing
chemicals known as perchlorates, which so far seem
to be ubiquitous in the Martian soil.
Scientists will continue to look for rocks that may
have higher concentrations of organics or better
chemical conditions for their preservation, Grotzinger
said.
"A key hurdle that we need to overcome is
understanding how those organics may have been
preserved over time, from the time they entered the
rock to the time that we actually detect them," said
Curiosity scientist Jennifer Eigenbrode with NASA's
Goddard Space Flight Center in Greenbelt, Maryland.
Curiosity currently is en route to a three-mile high
mound of layered rock rising form the floor of Gale
Crater, a formation known as Mount Sharp.
Based on the new information gleaned from the
Yellowknife Bay samples, scientists are developing a
new strategy to look for organics there.
Even if life never started on Mars, organic material
presumably would have been deposited on the
surface by crashing comets and asteroids.
news.yahoo.com/nasa-mars-rover-finds-evidence-life-friendly-ancient-213048603.html?.b=index&.cf3=Science&.cf4=2&.cf5=Reuters&.cf6=%2F

Waiting for that 'eureka' moment when the mars rover finds a fossil or very strong microbial evidence of life on that planet, strongly believe life must have existed in some form sometime in the past on mars...would probably be the scientific discovery of the century

Wow.. You beat me to creating this topic

emk4lif: Waiting for that 'eureka' moment when the mars rover finds a fossil or very strong microbial evidence of life on that planet, strongly believe life must have existed in some form sometime in the past on mars...would probably be the scientific discovery of the century

I'm also waiting for that Eureka moment, I think it might be next year or maybe this December.

Such a discovery would Change almost everything

Afrobasic: Wow.. You beat me to creating this topic

I'm also waiting for that Eureka moment, I think it might be next year or maybe this December.

Such a discovery would Change almost everything

Totally, would be amazing tho,