But the risk goes beyond the difficulty of the landing and the complexity of Curiosity’s 10 major instruments. That’s because Curiosity will land just as Congress and the administration debate a plan to slash NASA’s Mars and planetary programs significantly. NASA officials and Mars aficionados hope the rover will make discoveries that will limit the cuts, while knowing that a crash landing or failed instruments could further curtail the programs.
“I think a major discovery by Curiosity, such as finding the building blocks of life or any other indication of life, would certainly lead us to reconsider our science approach at Mars,” said James Green, director of NASA’s Planetary Sciences Division. “Why? Because if there is, or was, life on Mars, then we’d have to assume life is everywhere in the galaxies. We would have to rethink our place in the universe.”
‘Our place in the universe’
One reason that NASA has not sent a life-detecting mission to Mars in so long is that the first one came back with very disappointing results. The twin Viking landers touched down in 1976 with great anticipation that not only the building blocks of life but also life itself would probably be found.
Instead, the Viking mission found a cold, desert planet that came to be seen as virtually incapable of supporting life. While one life-detection experiment using nutrients brought to Mars and tagged with radioactive carbon did show positive results several times, NASA officials and other scientists concluded that those findings were most likely in error. More disheartening, the instrument designed to identify organic molecules came back with a finding of “no organics.” Without organics, virtually all scientists say, there can be no life.
But in the past decade, NASA scientists and others have produced evidence that the planet was once much warmer and wetter. They know, for instance, that the Gale Crater site was once covered in water, and they know that it has minerals and clays that can be formed only in the presence of water.
In addition, NASA astrobiologist Michael Mumma reported in 2009 finding plumes of methane gas erupting at specific spots and at predictable times on Mars. More than 90 percent of methane on Earth is formed as a byproduct of biology, from cows’ digestive systems and rotting trees to the life cycle of tiny microbes. It remains unknown whether some of the methane on Mars also comes from biological sources.