In today’s Academic Minute, Dr. Jan Amend of the University of Southern California explains efforts to understand microbes that live deep below the surface of the earth.
Jan Amend is a professor of earth sciences and biological sciences at the University of Southern California. His lab carries out research in microbial geochemistry with particular interests in shallow-sea hydrothermal systems and the deep subsurface biosphere.
Dr. Jan Amend – Seafloor Microbes
My NASA Astrobiology team is exploring the subsurface biosphere on Earth—life underground—so that we can guide the search for extraterrestrial life.
With respect to biology, the region deep beneath the Earth’s surface is largely unstudied. We don’t know how much life is down there or what kinds of organisms find the dark, rocky, high pressure, low nutrient subsurface a habitable place. How do these “intra-terrestrials” make a living?
Over the next five years or so, we will be dropping scientific equipment down many boreholes and mineshafts that reach thousands of meters below the surface, trying to catch a glimpse of the intra-terrestrials in their natural habitats. We will also collect samples, bring them back to the laboratory, and investigate these microorganisms.
So what does this have to do with the search for extraterrestrial life? Let’s take Mars for example. If life exists there today or ever existed there, evidence of that life is most likely in the subsurface. The surface conditions are simply too harsh to preserve any signatures of life.
But before we hunt for evidence of life in the Martian subsurface or on any other planet, let’s perfect our skills at home—here on Earth. If our estimates are about right, in a sample of water from the deep subsurface, let’s say tens to hundreds of meters down, only about one one-billionth (with a “B”) of that sample will be a microbial cell.
The techniques and equipment that we develop and refine over the next five years could, some day, find their way on a rover sent to Mars, or some other planet. Our exploration into the untapped world beneath our feet right here on Earth is a vital step toward finding life, if it is indeed out there, on another planet.