But Curiosity's research team is now turning its focus back on the ground, narrowing its search toward where exactly to find organic material that may have supported life on the red planet.
NASA's latest findings are spread across six different papers published in the online edition of the journal Science. In addition to thoroughly analyzing the data that led to the claim earlier this year that Mars could have harbored life once upon a time, the papers also address the chemical and geological clues that may guide where Curiosity travels next to hunt for organic material.
The hunt has been a difficult one on account of the high level of radiation on Mars' surface. "The radiation has so much energy that it breaks apart the chemical bonds," said Jennifer Eigenbrode, who co-presented Curiosity's most recent findings today at the American Geophysical Union's fall meeting. "It forms radicals and reacts with anything they can as quickly as they can. Understanding the chemistry is important to hypothesize what the story could have been [on Mars]."
Paul Mahaffy, a research scientist at NASA, said that because of that radiation, it's important to find patches of Martian land that were only recently exposed to the surface. "We need to look for a site that was recently eroded, like the site exposed by a fresh crater," he told ABC News. "If we were to find an area exposed for only 1 million years, we'd be happy, since there's a much better chance of preserving the original organic material."
And finding those sites may be easier thanks to knowing the geology of Mars as well. The new research suggests that Curiosity should look near the bases of downwind scarps, a specific type of cliff. By combining the radiation data with geological data, Mahaffy said that there's a better idea of where to hunt for organic material. "We need to drive close to a scarp that's been exposed for about 1 million years," said John Grotzinger, project scientist for Curiosity that also presented the new research. "We only need a few centimeters."
Mahaffy added that while it's good to officially confirm what NASA hypothesized several months ago about Mars' potential to harbor life, there's more to the picture. "We kind of knew that already," he said of the likelihood that there was life of Mars. Instead, he sees the real draw as confirming that radioactive dating methods that are commonly used on Earth work on another planet.
"We have a powerful technique for understanding the environment," he said. "We have three independent measurements and they're all close together. It's extremely reassuring since we can say, 'We must be doing something right.'"