“Some of the best evidence for life in space lives right here on Earth: It’s weird, adaptable, and far hardier than we ever thought.” —Alissa Zhu
Panspermia is the ancient idea that the seeds of life exist everywhere in the Universe. Spread like spores by stellar rocks and dust as well as by human-made space debris, they begin the process of evolution wherever they land – just as soon as they encounter the right conditions in which to thrive. If it takes 40,000,000 years or more for that to happen – well, who’s counting, anyway? The microorganisms remain ever ripe and ready for action. But what are the ideal conditions for life?
Scientists used to think they knew what constituted life and what all life forms needed to survive. But more and more, they’re becoming less and less certain – though no less eager to make horizon-stretching observations and break-through discoveries.
In the early ‘80’s, Professor Kenneth Nealson, then of Scripps Institution of Oceanography, got pulled into this pursuit when he heard reports of an inexplicable phenomena occurring at the bottom of Lake Oneida in upstate New York.
Every spring, snowmelt carried manganese from the mountains into the lake. As the winds stirred the water, they mixed the manganese with oxygen – which should have resulted in a substantial deposit of manganese oxide at the bottom of the lake. But for some reason, it didn’t.
MnO is an inorganic compound that is used for a multitude of purposes – for instance, as an additive for food and fertilizer, and as a catalyst in the manufacture of ceramics, paints, colored glass, etc. Evidently, something at the bottom of the lake was also putting it to good use; for MnO was disappearing 1000 times faster than the geologically expected rate.
Enter ‘extremophiles’ – those microscopic organisms that defy scientific expectations by surviving in places and under conditions that would be beyond the impossible for most life forms on Earth.
What Nealson discovered after several years of research was that a microbe was actually breaking down metal, which should also have been impossible. The breakdown was just part of its regular metabolic process. This was Nealson’s first introduction to Shewanella, one of a never before seen class of micro-bacteria with an affinity for raw electricity.
Nealson leads a team of researchers at USC who are dedicated to finding alien life forms on Earth – most particularly, the kind for whom a cathode looks like a banquet. The possibility of putting such creatures to work in a multitude of ways on behalf of humanity has everybody working overtime.
The detailed article on the subject, which appears in the February 2015 issue of Popular Science, ends with five steps for identifying alien life in outer space. The final one, which clearly reflects the recent discoveries, is stated thusly: “All life manipulates electrical energy. If the electric potential in the ground drops steadily with depth (as happens on Earth), that could indicate successive populations of microbes are pulling electrons from the environment. It would be a low-key First Contact, but revolutionary all the same.”