April 14, 2004

Cornell's Man on Mars

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It cannot be seen through the rainclouds, but somewhere up in the sky, two rovers are driving around on Mars collecting data.

Yesterday, students and faculty had to go no farther than Goldwin Smith Hall to reap the benefits. Prof Steve Squyres Ph.D.’78, astronomy, who is the mission’s science team leader, gave an overview of the mission to a packed audience in the Hollis E. Cornell Auditorium and explained how the rovers work and what they have found.

The missions’ two sites, Gusev Crator and Meridiani Planum, were chosen because they were safe to land on and close to the equator, where the rovers’ solar panels will be most effective, Squyres said.

“Beyond that, the sites were chosen to be places that seemed to have the highest possible likelihood of having once been potentially habitable environments on Mars,” he added.

He elaborated that the scientists are not looking for life or fossil remains, “but what we are looking for is evidence that this was a place that would have once been a suitable, habitable environment.”

On March 2, the team announced that they found this evidence at Meridiani Planum site. Squyres said that the site itself was chosen because orbiting satellites detected that it had an abundance of the mineral hematite. Squyres explained that hematite is created in many ways, most of which involve liquid water.

“It’s sort of like a chemical beacon visible from space saying, ‘here, look here,'” he said.

When the rover, Opportunity, examined the site, it found that there was hematite everywhere except where the rover’s pod had bounced as it landed. Further examination showed that this hematite was concentrated in small, hard, round granules, which the science team called blueberries. These blueberries were embedded into an section of bedrock in the area as well as being in the sand.

According to Squyres, these appear to be concretions, which he said are formed when materials in porous rock are dissolved by liquid water and seep out. Various chemical properties of the rock, such as the distribution of certain elements and the presence of a mineral called Jerosite, also confirmed that it seems to have been formed in water.

Squyres said that Opportunity is now headed towards another crater, called Endurance, which he said may provide an even greater source of evidence that there was once water on Mars.

“If there were one page in the book of Martian history preserved within the 30 or 40 centimeters of rock in Eagle crater [where the blueberries were found], there may be a library in Endurance,” he said.

Squyres also spent time talking about the Spirit rover, whose explorations of Gusev Crater have not yet come up with any breakthroughs. He said that chemical analysis of rocks and soil there have shown that “it just looks like average Martian dirt.”

Squyres said that Spirit is now traveling toward a set of hills about 3km from the site. He explained that the scientists hope to find rock formations which will tell them “about the aqueous history which we still believe took place at Gusev Crater but which has so far been hidden from our view.”

The audience seemed to find Squyres’ talk informative and interesting.

“I’ve been following the mission since it was launched and we talk about it in our astronomy class,” said Jennifer Hanley ’06. “It’s very interesting to hear about the hematite and evidence of water on mars. It’s very exciting.”

Stephen Zinder, chair of the microbiology department in the college of Agriculture and Life Sciences, said that he found the talk interesting because of its implication that there might have been life on Mars.

“I worked on microorganisms involved with biogeochemistry on Earth. I’ve always wanted to expand to another planet,” Zinder said.

He said that although Mars’ surface is unsuitable for life, it is possible that there is life underneath the surface, as there is on Earth.

“But it’s all conjecture. It’s interesting to see some real data on the Martian surface.”

Archived article by Yuval Shavit
Sun Staff Writer