New Rover Spies Layered Rocks on Mars

AP ^ | 31 minutes ago | ANDREW BRIDGES

[BenLurkin]

A NASA (news - web sites) rover got its closest-ever look at bedrock on the surface of Mars on Tuesday, and scientists were eager to determine whether the layering could have been formed in water.

The Opportunity rover spied the fine-scaled layering just days after it landed in a small crater on the far side of the planet from its twin, Spirit. On Tuesday, NASA unveiled a high-resolution photograph of the horizontally striped and fractured slabs of bedrock.

"Look at the wonderful layer cake-structure in there," said Steve Squyres, the mission's main scientist, as he excitedly narrated a slow pan of the black-and-white image. "It's going to be fascinating beyond words to get up close and personal with this thing."

The find is a significant one: Each roughly half-inch thick layer represents an event in the geologic history of the Red Planet that Opportunity should be able to reconstruct with its complement of cameras and scientific instruments.

Scientists believe the layers were laid down billions of years ago, piling up either as ash spewed by successive volcanic eruptions or as sediments borne by wind or water.

Some scientists believe the 18-inch-high band of layered rocks is cross-bedded in part, suggesting a sedimentary origin that would require the presence of water.

If so, the rocks could provide tangible evidence that Mars once was a wetter place capable of sustaining life. Images taken from orbit already suggest vast amounts of water once flowed across the surface of the planet.

The slabs of bedrock rim a portion of the shallow depression near where the six-wheeled robot sits atop its lander.

The Opportunity rover was in good shape after its weekend landing but had developed a small, 15-watt power loss that worried NASA.

Engineers believe a heater in the shoulder of its robotic arm has been turning on unnecessarily when temperatures drop. Engineers continued to monitor the situation, unsure if it could harm the rover.

"We're very paranoid people," mission manager Jim Erickson said.

The Spirit rover, 6,600 miles around the planet, continued to recover from computer problems that last week brought its science work to a halt. Engineers received additional data they hope will help them understand the problem.

Opportunity should roll off its lander sometime in the next two weeks. This week it is scheduled to put to use its mini-thermal emissions spectrometer, an instrument that measures infrared radiation, to reveal what minerals the rocks contain.

Together, the pair of 384-pound rovers make up an $820 million mission to prospect for geologic evidence that Mars was once a wetter world capable of supporting life.

[BenLurkin]

"Some scientists believe the 18-inch-high band of layered rocks is cross-bedded in part, suggesting a sedimentary origin that would require the presence of water."

They keep reaching - maybe they'll hit.

[Conspiracy Guy]

I put that rock there. If they would look down they would see my boot prints. NASA is so naive.

CG

[BenLurkin]

"We're very paranoid people," mission manager Jim Erickson said.

[LibWhacker]

A person would have to be blind not to be able to see the layering.

[John H K]

Well, the issue is the cross-bedding.

I'm not quite qualified enough to spot cross-bedding, but I know what it is.

Curious if any geologists could comment.

[John H K]

Err, not qualified enough to say definitively where any cross-bedding would be in the Mars photograph.

The right side? Looks like the most layered area.

[MineralMan]

I'm not a professional geologist, but I can tell that this photo simply isn't detailed enough to make the judgment. When the rover can move closer and take some more photos, then get really close and do some microscope photos, as it is equipped to do, we'll have more answers.

This photo, however, looks a great deal like sedimentary rock that is partly eroded and smoothed by flowing water. Lots of creeks around here with similar rocks.

Time will tell.

[LibWhacker]

Most exciting thing to happen in space exploration since the moon landings, imo. Can't wait for Opportunity to roll off the lander and go over there!

[John H K]

Well, you can get Cross-bedding from wind deposits too. (But on close inspection one should be able to easily tell whether it's wind or water from the particle size.)

I think I see where they might be talking about.

It's certainly not as obvious as some of the pics of textbook examples of cross-bedding on earth on the net, but few cross-bedded sediments are:

http://earthnet.bio.ns.ca/english/glossary/c/cross_bedding.html

http://www.lbcc.cc.or.us/geo102/Overview/sld016.htm

[Conspiracy Guy]

That is a picture of my backyard. This is so fake!

CG

[MineralMan]

"Well, you can get Cross-bedding from wind deposits too. (But on close inspection one should be able to easily tell whether it's wind or water from the particle size.)
"

True, but it generally takes water to dissolve whatever cementing substance to solidify wind-blown deposits. Still, the microscopic examination will tell the tale.

[Huck]

Very cool.

[billorites]

"Most exciting thing to happen in space exploration since the moon landings, imo."

I dunno, I still think Hubble is the best thing, at least in terms of astronomy, ever.

[Rebelbase]

I agree, the right side shows linear features that could be associated with layering.

[John H K]

Well, it's obviously layered, but the question is whether it's cross-bedded.

Notice in the pics that the ANGLE of the layering differs as you look at different parts of the outcrop?

Now, that could be tectonically folded but it's rare to see folds that tight in that small an area, particularly with what is theorized about the history of Mars.

It's more likely it could be cross-bedded.

And volcanic deposits aren't cross-bedded. Sedimentary deposits often are.

[Muleteam1]

Your photo sure seems to show exposed consolidated sandstone layers of an ancient streambed or sand dunes partially covered by wind-blown sediment. The fractured surface is really interesting. However, I am by no means a geologist having only minor in the subject. And I can tell you, several layers of sediment have by now settled on that degree.

Muleteam1

[BenLurkin]

Isn't 'cross-bedding' when cousins get too friendly?

[UCANSEE2]

About the water. It is very important. In many ways.

They say the inclusion of water on a planet is the indicator of life.

This is true. On planets where God wants life, water is found/placed/discovered/there (pick one).

(total aside)Is this the 'breath of life' in the Bible. Was man formed from the dust of the ground, by adding water?< P>If God does not want life, guess what.

God giveth, and God taketh away.

It is possible (highly probable) that Mars HAD water, and now it appears that there is not much (or any) water left.

[Lazamataz]

"Look at the wonderful layer cake-structure in there," said Steve Squyres, and fifty-million Atkins dieters groaned in anger.

[MineralMan]

"Your photo sure seems to show exposed consolidated sandstone layers of an ancient streambed or sand dunes partially covered by wind-blown sediment. The fractured surface is really interesti"

Sheesh! I'm a complete idiot, and didn't notice how wide the photo was. When I finally scrolled across it, lots more became clear.

Especially interesting is the group of rocks near the right edge. It clearly looks like selective erosion, probably by wind, of some of the rocks, exposing horizontal (almost) ridges with deep hollows between them. This almost exclusively occurs in sedimentary formations where harder layers remain and softer layers erode.

I'm betting on water-deposited sedimentary rocks.

Note, too, that these are below the rim of the crater, where they were exposed by the impact, but below the surrounding surface. The fracturing may have been caused by the impact, but long enough ago to allow this erosion.

Fascinating.