Rovers find evidence of water on Mars

[Chrome]

NASA: Liquid water once on Mars

Evidence red planet was once 'soaking wet'

By Marsha Walton

CNN

Tuesday, March 2, 2004 Posted: 2:30 PM EST (1930 GMT)

(CNN) -- Mission accomplished.

NASA scientists say the Mars rovers have found what they were looking for: Hard evidence that the red planet was once "soaking wet."

"We have concluded the rocks here were once soaked in liquid water," said Steve Squyres of Cornell University. He's the principal investigator for the science instruments on Opportunity and its twin rover, Spirit.

"The second question we've tried to answer: Were these rocks altered by liquid water? We believe definitively, yes," said Squyres.

Squyres and other NASA officials made the announcement at NASA headquarters in Washington, after several days of giving tantalizing hints that something significant had been discovered.

"Three and a half years ago, in July 2000, we were on stage here to talk about sending two rovers to get evidence of past water. NASA and its international partners have turned those dreams to reality," said Ed Weiler, NASA associate administrator for space science.

Scientists used instruments on board the golf cart-sized rovers to study the composition of the rocks and soil on the planet. The rocks' physical appearance, plus the detection of sulfates, make the case for a watery history, and more important, an environment that could have been hospitable to life.

Spirit and Opportunity were sent to opposite sides of the planet with the possibility of investigating different types of terrain. Spirit, the first rover to arrive on January 3, landed near the Gusev Crater, which may once have held a lake.

But geologists and other researchers at NASA's Jet Propulsion Laboratory in Pasadena, California, were thrilled when they saw the possibilities surrounding Opportunity, which landed three weeks later. It landed inside a small crater in the Meridiani Planum, one of the flattest places on the planet. And its landing site was within driving distance for the spacecraft to reach an exposed slice of bedrock.

Since its landing January 25, Opportunity has used the same tools as a human field geologist would to determine the chemical contents of the rocks. Using an alpha particle X-ray spectrometer, a device that can identify chemical elements, scientists have identified a high concentration of sulfur in the bedrock.

Another instrument on board, a Moessbauer spectrometer, has detected an iron sulfate mineral known as jarosite. From their knowledge of rocks on earth, scientists say rocks with as much salt as this Mars rock either formed in water, or had a long exposure to water after they were formed. The scientists say these rocks could have formed in an acidic lake or even a hot springs.

Scientists say the case for a watery past is further strengthened by the pictures taken by the rovers' panoramic cameras and its microscopic imager. One target rock, named "El Capitan," is filled with random pockmarks. Geologists say a texture like that comes from sites where salt crystals have formed in rocks that have sat in salt water.

Scientists say they have gained other clues from the physical appearance of the rocks. They see a pattern called "crossbedding," which is often the result of wind or water moving across the rock's surface.

The cost of the two rover missions is about $820 million dollars. With solar panels and lithium-ion battery systems aboard, each rover is expected to function and communicate with earth for about 90 Mars days, known as "sols." That's equivalent to 92 earth days.

[BruceH]

Cool.

Now, on to Europa!

[BFrank]

This has been a really interesting adventure. Forget the rediculous "manned Mars initiative" by our 'appointed one', this is exciting and it is happening NOW!

It's really great to go to their website - Mars Exploration Rover Mission - and look at all the latest news. Not to mention pictures......LOTS of them. If you dig into the site, you can find a page that gives you the opportunity to see every single picture downloaded from Mars. There are literally thousands of them.

Edited March 3, 2004 by BFrank