Bacteria from space
In impossible environments, kilometers below the earth and in the atmosphere, you find forms of life. New hopes for Mars?

A deep mine. In one of these abysses bacteria were found that lived on hydrogen and resisted radiation.
A deep mine. In one of these abysses bacteria were found that lived on hydrogen and resisted radiation.

Indian and English scholars have turned their attention to space, and have discovered that there are living organisms at tens of kilometers above the earth's atmosphere. The project, organized by research institutes in India, has sent some aerostatic balloons equipped with "cryogenic samplers", instruments that collect samples from the atmosphere, to about 40 kilometers above the Earth. The collected bacteria were then, with great difficulty, grown in the laboratory by Milton Wainwright of the University of Sheffield. The result was the isolation of a fungus and two bacteria from one of the "spatial" samples. The bacteria themselves are not very different from those living on Earth, says Dr. Wainwright, but there are some interesting differences that indicate a different origin.
Meanwhile, in the mine …
If you look down, you probably see the most infernal of environments. Yet even there some bacteria manage to live. Recent studies in a South African gold mine, over 3.5 kilometers deep, have led to the discovery of life forms that can survive only with sulfur and hydrogen, which they find in the hot and radioactive water of the mine. Hydrogen, present in the water at very high concentrations (about one hundred million times more than normal) probably comes from the dissociation of the water itself by the radioactive uranium. A completely new way of maintaining life, says John Baross, a depth bacteria scholar who works at the University of Washington in Seattle.
Mars and Earth. According to some scholars, these bacteria could be similar to those that inhabited the Earth at the beginning of the history of life, or even to those who now inhabit other planets of the solar system like Mars; which contains water and uranium, although not as much as the Earth. Even the genetic sequences of these bacteria are different from any other terrestrial bacterium.

(News updated December 18, 2002)