NASA: "Mars' Opportunity Mission Reaches 11 Years in Its Search for Ancient Life"
Today's 'Galaxy' Insight --Freeman Dyson

Sunset at Mars' Gusev Crater -- "An Ancient Habitat for Life?"

 

 

Whatmakesmar

 

Wide view of sunset over Gusev Crater taken by NASA’s Spirit Rover in 2005. Both blue aureole and pink sky are seen. Because of the fine nature of Martian dust, it can scatter blue light coming from the Sun forward towards the observer.

The "Pot of Gold" rock outcrop in Gusev Crater that Spirit Mars Rover examined in late 2005 revealed high concentrations of carbonate, which originates in wet, near-neutral conditions, but dissolves in acid. The ancient water indicated by this find was not acidic; hence, it was favorable as a habitat for life.

"This is one of the most significant findings by the rovers," said Steve Squyres of Cornell University a principal investigator for the Mars twin rovers, Spirit and Opportunity. "A substantial carbonate deposit in a Mars outcrop tells us that conditions that could have been quite favorable for life were present at one time in that place."

Spirit inspected rock outcrops, striking a bonanza at one the NASA scientists named Comanche, along the rover's route from the top of Husband Hill to the vicinity of the Home Plate plateau. Magnesium iron carbonate makes up about one-fourth of the measured volume in Comanche. That is a tenfold higher concentration than any previously identified for carbonate in a Martian rock.

"We used detective work combining results from three spectrometers to lock this down," said Dick Morris, a member of a rover science team at NASA's Johnson Space Center in Houston."The instruments gave us multiple, interlocking ways of confirming the magnesium iron carbonate, with a good handle on how much there is."

Massive carbonate deposits on Mars have been sought for years without much success. Numerous channels apparently carved by flows of liquid water on ancient Mars suggest the planet was formerly warmer, thanks to greenhouse warming from a thicker atmosphere than exists now.

 

Gusev_homeplate_fumerols_20081001_12_1024

 

Shown above is a National Geographic artist's concept of how Gusev Crater might have appeared billions of years ago. The ancient, dense Martian atmosphere was probably rich in carbon dioxide, because that gas makes up nearly all the modern, very thin atmosphere. It is important to determine where most of the carbon dioxide went. Some theorize it departed to space.

Others hypothesize that it left the atmosphere by the mixing of carbon dioxide with water under conditions that led to forming carbonate minerals. That possibility, plus finding small amounts of carbonate in meteorites that originated from Mars, led to expectations in the 1990s that carbonate would be abundant on Mars. However, mineral-mapping spectrometers on orbiters since then have found evidence of localized carbonate deposits in only one area, plus small amounts distributed globally in Martian dust.

Spirit's Alpha Particle X-ray Spectrometer instrument detected a high concentration of light elements, a group including carbon and oxygen, that helped quantify the carbonate content.

The Daily Galaxy via NASA/JPL-Caltech

Comments

I suggest to reconsider plans to search for life in the universe. Maybe, what we really want is to find one or several Earth-like planets suitable for human living now or in the future.

great....waiting for rover's new discovery.

Terraforming Mars will be a mammoth task, but it must be done. Having the whole of humanity all on one vulnerable world is a formula for eventual disaster, but a second home would reduce our risk of extinction to a very small fraction of the present situation.

Terraforming Mars should be the second most urgent task for the world's many nations, the most urgent being to tame fusion power in order to buy us time before some rogue asteroid slams into our planet in an extinction level event. When that happens, we won't have Bruce Willis to save the world - yet again...

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment

Your Information

(Name is required. Email address will not be displayed with the comment.)