Click here to sign up, or log in . Even Dante would blanch at the conditions kilometers below the earth's surface. Temperatures climb past 100 degrees Celsius, pressures hundreds of times greater than atmospheric pressure bear down, and space is so tight even microorganisms can barely budge. Yet, even there life persists. Now subsurface scientists have begun to identify the factors that determine why microorganisms survive deep underground in some places, but not others, report researchers from the Department of Energy's Idaho National Engineering and Environmental Laboratory and Princeton University.
High temperatures ensure nothing can live too far below the earth's surface.
As recently as the 1980s most microbiologists thought nothing could survive far below the soil layer. They now know extremophiles live embedded in rock hundreds of meters below dry land, in deep ocean sediments and in fissures crisscrossing the ocean floor. A better understanding of how extremophiles survive deep underground may shed light on how life endured the earth's violent youth, or show scientists where to look for life on other planets, said Princeton geochemist T.C. Onstott. Temperature appears to be the primary factor in limiting how deep extremophiles can go. No known microorganism can live for long at 120 degrees Celsius.