Mars Up Close

Mars Up Close

Scott Murchie's team of scientists helps uncover the secrets of the red planet

By Tom Nugent


 
spectrometer images
These images were taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) now orbiting the planet. The spectrometer takes the sharpest pictures of Mars ever, including, in these images, showing carbon dioxide frost in Russell Crater.
Drop by Murchie’s sprawling, computer-jammed laboratory at the APL on a typical weekday afternoon, and the odds are high that you’ll find him leafing through giant cyber-maps of such intriguing Mars locales as the West Candor Chasma and the Nili Fossae Trough. At this point CRISM has already mapped more than half of the planet and made more than 6,500 high-resolution observations of the Martian surface, Murchie said, leading a brief tour of the buzzing facility.

“The orbiting camera we use for all of this has a pretty fancy name—imaging spectrometer—but it’s really just like any other camera, with one major difference: CRISM takes its images in five-hundred forty-four colors that are reflected in sunlight. Its highest resolution is about twenty times sharper than any previous observations ever made in the near-infrared wavelengths, which is why CRISM has been discovering more about Mars than any other instrument yet flown to the planet.”

In spite of the project’s undeniable success at gathering knockout images of the Martian landscape, however, Murchie is philosophical about the attention—or lack there of—that CRISM got from the mainstream news media. “The problem is that we don’t have the glitz of a Mars rover,” Murchie said, describing the widely publicized Mars Exploration Rover (MER) landings, in which two frisky, wheeled robots zipped across the Martian surface to delight millions watching MSNBC and CNN.

“Don’t get me wrong. The rovers do great science, but because they’re dune buggies, they often seem to get all the attention. Driving a dune buggy across the surface, as opposed to just taking pictures ... well, I guess that’s sexier.”

“Its highest resolution is about twenty times sharper than any previous observations ever made in the near-infrared wavelengths, which is why CRISM has been discovering more about Mars than any other instrument yet flown to the planet.”

Scott Murchie '81, CRISM Principal Investigator

Prosaic as a camera may appear to some rover fans, however, the story of how CRISM has been snapping all those high-resolution photos of the Martian surface in recent months is thrilling, in Murchie’s view. Launched in August 2005 from Cape Canaveral in Florida, the big camera hitched a ride aboard the Mars Reconnaissance Orbiter for the more-than-300-million-mile journey. It now orbits Mars, looking down on the planet’s red deserts, jagged meteor scars, and underground ice.

What CRISM has been doing most of the time is looking for areas of Mars that were once wet enough to leave behind a “mineral signature on the surface,” Murchie said. The camera is searching for the spectral traces of aqueous and hydrothermal deposits—while at the same time mapping the geology, composition, and stratigraphy of the surface features.

“One of the most exciting features of this powerful camera,” he said, “is that it can clearly observe areas—from a distance of about one-hundred ninety miles—that are no more than sixty feet across, which means that it can see and then photograph objects that are no larger than a typical house. And that’s a fabulous resource if you’re interested in learning about things like topography and rock formations and soil structure.”

After nearly two years of studying the planet in detail, Murchie says the evidence shows clearly that Mars must have contained “a great deal of liquid water” at some point, and that it “could easily have provided a habitable environment for life as we know it to have evolved on the Martian landscape.”
phoenix
The Phoenix unmanned spacecraft, now collecting and analyzing samples of Martian ice.

Ask him to reflect on the philosophical implications of life on Mars, and this avid gardener (he raises viburnums and other American trees and shrubs at his rural spread in Mt. Airy, Maryland) will tell you that he isn’t troubled at all by the thought that we may not be alone in the cosmos.

“I’m a scientist, but I also like to think that I’m a religious person,” said Murchie, who often teaches Sunday school at his local Methodist church. “I think both ways of seeing reality are valid, and I don’t have any problem at all with the idea that there might be life elsewhere in the universe.”

Then, pausing over his cup of cooling Dunkin’ Donuts coffee, he breaks into a smile. “Did you see Contact, that film with Jodie Foster about life in another galaxy, and she discovers it with a radio telescope?

“She has this great line in the movie that I’ve never forgotten, where she asks somebody: ‘Wouldn’t it be a waste—if the earth turned out to be the only place in the cosmos where there was life?’

“I think that’s a great way to think about the possibility that we may soon discover evidence of past microbial life on Mars, and I’m delighted to be doing my little bit to help solve the puzzle by taking pictures of rocks.”
 
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