Renewed Hope for Life on the Red Planet

Is anything stirring on the dusty surface of Mars? A few bold scientists say we need speculate no longer: We have already found strong evidence of life there.

For those seeking life on Mars, it is the best of times and the worst of times. Nearly 35 years after NASA’s twin Viking robots eased down onto its ruddy surface, there is still no incontrovertible evidence that living organisms ever existed on the fourth planet from the sun. Few researchers accept one scientist’s claims that the 1976 Viking experiment detected life. The brief frenzy over possible fossils in a Mars meteorite has fizzled. And even after billions of dollars’ worth of adorable rovers and eagle-eyed orbiters have prodded and probed the planet, the results have been at best ambiguous and at times downright confusing.

Yet a growing number of space scientists are upbeat, even buoyant, about the likelihood that Mars is a living world. “A variety of discoveries are creating a kind of buzz,” says Chris McKay, an astrogeophysicist at NASA Ames Research Center in Mountain View, California. “And people seem more enthusiastic. It’s group psychology.” There has been no single major breakthrough in the search, but a subtle change is taking place within the clubby community dedicated to finding and bringing back organisms—dead or alive—from the Red Planet.

“It is not now considered a stupid idea to look for life on Mars,” says Bruce Jakosky, a planetary geologist at the University of Colorado at Boulder. “In recent years the case has been made again and again that life is or was possible there.” Undergirding this new optimism are reams of data—from Earth-based telescopes as well as Mars orbiters, landers, and rovers—that have slowly painted a much more complete and complicated picture of the Mars environment stretching back billions of years, providing intriguing hints that microbes might have once evolved there, and might yet endure.