It is possible, Farmer says, that Martian microbes could spend most of their time as inert spores “waiting for something good to happen,” only springing to life given the right and very rare conditions. The reality may be more complex: on Earth, some resilient organisms such as tardigrades can enter a profound, almost indefinite state of hibernation when deprived of moisture, preserving their desiccated tissues but neither growing nor reproducing. Without liquid water, Farmer points out, one would naively think organisms cannot function.

“But what is the quality of that water? Is it really salty-too salty for life?” “There are many indications of water on Mars in the past, perhaps reservoirs of water in the near subsurface as well,” he says. “It all started out with ‘follow the water ’ not necessarily ‘follow the life’…but ‘follow one of the basic requirements for living systems,’” says Arizona State University geologist Jack Farmer, referring to NASA’s oft-repeated mantra for Martian exploration. Talk about looking for Martians and you inevitably talk about water, the almost-magical liquid that sustains all life on Earth and seems to have served as an indispensable kick-starter for biology in our planet’s deepest past. Instead, they are getting more creative, proposing new strategies and technologies to shape the next generation of Mars exploration. But as the proceedings of this year’s Astrobiology Science Conference held here in April made clear, life-seeking scientists are not giving up yet.

Of course, the perplexing quest to find life on Mars may have a simple solution: It’s not there, and never was. For example, could there be a “cover up” whereby the harsh Martian environment somehow obliterates all biosignatures-all signs of past or present life? Or perhaps life there is just so alien its biosignatures are simply unrecognizable to us, hidden in plain view. But astrobiologists continue to, quite literally, chip away at finding the truth.Īs the search becomes more heated (some would say more desperate), scientists are entertaining an ever-increasing number of possible explanations for Martian biology as a no-show. No convincing signs of life have emerged. Yet against all odds (and researchers’ hopes for a watershed discovery), Mars remains a poker-faced world that holds its cards tight. The odds are good, many scientists say, for the Red Planet being an extraterrestrial address for alien life-good enough to sustain decades’ worth of landing very expensive robots to ping it with radar, zap it with lasers, trundle across its terrain and scoop up its dirt. MESA, Arizona-Since the dawn of the space age NASA and other agencies have spent billions of dollars to reconnoiter Mars-assailing it with spacecraft flybys, photo-snapping orbiters and landers nose-diving onto its surface.

Mars by Leonard David