Curiosity's Mars Crater Was Once a Vast Lake

astroengine writes The mountain that NASA's Mars rover Curiosity is exploring appears to have once been a lake, scientists said Monday. Mount Sharp, a three-mile-high mound of layered debris rising from the floor of Gale Crater, is believed to have formed billions of years ago, images posted on NASA's website ahead of conference call with reporters show. Sediments to create the mountain likely originated from the crater rim highlands and were transported toward the center of the crater in alluvial fans, deltas, and wind-blown drifts, scientists said. "During wet periods, water pooled in lakes where sediments settled out in the center of crater," NASA said. "Even during dry periods in the crater center, groundwater would have existed beneath the surface. Then, during the next wet period it would resurface to form the next lake. This alternation of lakes, rivers and deserts could have represented a long-lasting habitable environment."

Comments

Great

[RobinH]

So why is it so hard to find fossilized evidence of previous life then?

Re:Great

[rockout]

Perhaps because evidence of water does not guarantee life was ever present in that water.

Re:Great

[edibobb]

Fossils are not that common on earth. Pick a random place on earth, then do about as much looking around as a Rover can do. You'll be very lucky to find a fossil.

Re:Great

[Nyder]

So why is it so hard to find fossilized evidence of previous life then?

Big planet and we aren't by the exposed stuff. While we do find stuff laying out in the plain site on earth, that isn't usually how they find fossils. Some digging is required and a lot of time nature will do something to expose fossil. Mars doesn't have weather like ours, so chances of having a landslide or something is less.

If we had a million peeps walking around on mars, then yes, maybe we'd find some fossils if they exist, but 1 rover on that planet? We'd be really lucky, IMO.

Re:Great

[gstoddart]

So why is it so hard to find fossilized evidence of previous life then?

You're joking, right?

The original mission was:

The mission's scientific objective was to search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars.

Having been sent there to see if water could have been there and if we can find evidence of that, and after being a huge success, lasting longer than planned, and giving us evidence that, yes, at one point Mars had liquid water ... you're actually bitching that it hasn't found fossils? Seriously?

Re:Great

[flyingsquid]

It's not as if you're going to be able to crack open one of those rocks and find the Martian equivalent of a trilobite. For most of Earth's history, the dominant forms of life were microbes, and only in the last 600 million years or so when oxygen levels increase do large multicellular forms appear. Mars, assuming it ever had life, probably never got that far. So fossil evidence will consist of fossilized microbes- which will require cracking open rocks, thin-sectioning them, and inspecting them under a microscope. The other possibility is doing chemical analyses of the rocks and looking for geochemical evidence of life- isotopic ratios or organic compounds that could only be explained by the presence of life. Either way, it will require a fairly sophisticated laboratory. Either we have to conduct a sample-return mission, or we need to develop miniature laboratories that can be sent to Mars.

Although it now seems as if there is a third option. Recently, a meteorite was discovered which appears to represent a sedimentary rock from Mars. It's spendy stuff- $10,000 a gram- but that's vastly cheaper than a sample-return mission. A multimillion-dollar program to prospect for Martian meteorites on Earth is another way to look for Martian sedimentary rocks.

Re:Great

[camperdave]

Wrong robot. It's Curiosity that's in the alleged lake bed, not one of the MERs (Spirit or Opportunity)

Until they find ....

[PPH]

... beer cans, tires, fishing tackle and a boat motor, I'm skeptical.