Later this year, nearly 300 of the brightest scientists on Earth will begin holding their breath as the most high-tech rover in NASA's storied history touches down on the airless surface of Mars and begins seeking proof of the possibility of life beyond our atmosphere.
And, if all goes right, one of those watching eagerly--Jennifer Eigenbrode, an astrobiologist at NASA's Goddard Space Flight Center--may be given the biggest thrill of her career. Her particular "wet chemistry" test aboard Curiosity, or the Mars Science Laboratory, could end up as the critical measurement for the presence of the complex carbon building blocks of life.
"I get chills, even now, just thinking about the possibility," Eigenbrode says. "Everything life needs is there on Mars. We've just never had access to study it, to see if the ingredients to support some form of life exist on Mars."
Curiosity was built precisely to test soil and rock samples to see whether Mars has ever had the ability to sustain microbial life.
The rover was successfully launched in November, and then survived its first in-flight communications test. It's scheduled to touch down on Mars in early August. That's when the meticulous science work--as if getting a rolling laboratory all the way to Mars could be labeled non-meticulous--begins: examining Mars' "habitability," the potential for life of some sort to survive in its extreme environment.
The trick is to determine whether organic carbon has survived on Mars, or whether the oxidizing surface of the planet or cosmic radiation from space has made it impossible for such complex macromolecules to survive. You also need to know where to look.
"There are chemical and environmental clues about where to go to look for it," Eigenbrode says, and Curiosity is headed to a particularly promising spot. Still, it's a sophisticated, educated guess about where to find the proverbial needle in the haystack. "It's an informed and guided search."
There's a lot riding on the Mars Science Laboratory for NASA. It may, in fact, be the agency's best hope of reigniting the public's interest in space exploration. The White House and Congress don't seem interested in sending a manned mission to Mars anytime soon. So the Curiosity rover may have to serve as the American public's virtual eyes and ears on Mars for the near term.
Eigenbrode is a relative latecomer to the Mars Science Lab effort. But a novel process she developed--with a chemical agent tested against soil from Earth that closely approximates what will very likely be found on Mars and which would break down and test native materials for markers or indications of life--was added to the battery of onboard tests on Curiosity toward the end of the planning process.
Her breakthrough, though, will be used only if scientists find something promising from the soil and rock samples the rover gathers, "if we know there is organic material present."
"Determining whether organic carbon is there is a fundamental question for us," she says. "Any organic carbon there would go through some sort of transformation. But there are lots of reasons to suspect that there may be complex macromolecules in Martian rocks."
While Eigenbrode and other astrobiologists are appropriately cautious with predictions about the potential for life in Mars' extreme environment, they say they won't be the least bit surprised if they find something that looks like an indication that life could, or does, exist there.
"Life is in every nook and cranny of Earth," she says. "We find it everywhere we look, in the most extreme environments like deepwater vents, in nuclear reactors. So if life ever arrived on Mars, it most likely would have adapted to the environment."
The Mars Science Laboratory is an extraordinary effort. The NASA science team has essentially managed to place an entire science lab on board, with the ability to run many tests remotely. "It's such a unique rover," she says. "We want to satisfy as many of the habitability science questions as we can."
And if the test she developed finds something? Eigenbrode starts to get nervous, and anxious, at the thought.
"We have no idea, yet, what might happen next. We're going to learn so much about Mars," she says. "We are opening up a whole, new book in our Mars observations."