On a road trip to Mars

There may be no better measure of the advance of technology during the space age than a count of photographs from Mars missions. Mariner 4 shot fully 21 pictures when it flew by Mars in 1965. Nearly half a century later, the Mars Exploration Rovers Spirit and Opportunity have returned more than 270,000 images from the surface of the Red Planet.

Mariner 4 image showing craters in the Memnonia
Fossae region of Mars. Some folks were still
expecting canals. Photo: NASA, NSSDC.

Ron Hobbs calls the rovers “one of the incredible feats of the space age.” Hobbs, a NASA solar system ambassador, gave a talk titled “The Great Martian Road Trip” during Mars Fest last Saturday at the Museum of Flight in Seattle.

While there weren’t many photos from Mariner, Hobbs said there were enough to debunk a century of belief that there might be a civilization on Mars. Mariner found not canals but craters.

“Overnight Mars went from a place that might have intelligent Martians building civilizations and canals to a place not much different from the Moon,” Hobbs said.

We followed the Mariner mission with the Vikings, which were equipped to look for signs of life.

“At that point we still believed that Mars could be habitable,” Hobbs noted. And the Viking landers actually found signs of life.

“But there was a problem,” Hobbs said. “There were no dead bodies. There was no organic material in the soil.”

With that, scientists concluded there wasn’t much happening on Mars, and we lost interest for a couple of decades. Oddly enough, Viking I may well have found organics, but just didn’t see them. A couple of years ago the Phoenix lander found perchlorates in the soil of Mars, and perchlorates would have masked any organics that Viking may have come across.

Spirit and Opportunity have clearly been the sexy rovers that have captured our imaginations. Hobbs recalled that the museum had a Mars Fest in 2004; Spirit was already on Mars, and Opportunity landed later that night.

“Nobody would have imagined that seven years later at least one of them would still be roving the Martian surface,” he marveled. Spirit is stuck in the sand and quiet, but Opportunity is still rolling and working.

The Museum of Flight had a full-size model of the Mars Science
Lab Curiosity on exhibit last year. The real one is set to launch
this fall. The auto-sized rover includes a rock-zapping laser.
Photo: Greg Scheiderer.

The next generation of Mars rover is Curiosity, an automobile-sized rover that is scheduled to launch later this year. It’s a complex geochemical laboratory that Hobbs said has a broader mission.

“In addition to looking for water, NASA is now beginning to look for organic materials, that is, carbon-based materials on Mars,” Hobbs said. “The mantra is shifting now from follow the water to follow the carbon.”

Hobbs is enthusiastic about the Mars missions.

“I don’t need any justification for exploring,” he said, adding that his own curiosity compels him to climb hills to see what’s on the other side. “But I do hope that what we’re learning on Mars and some of the other worlds of the solar system will help us protect the only planet that we know of right now where there’s life.”