Posted: Thu, Jan 17, 2002, 2:08 PM ET (1908 GMT)
Two separate studies published in Thursday's issue of the journal Nature provide both good and bad news for the prospects of microbial life on Mars. One report in Nature discussed the discovery of microbes that live 200 meters below the surface in Idaho, subsisting only on hydrogen and carbon dioxide gasses dissolved in groundwater. The conditions there would be similar to those below the Martian surface, provided subsurface liquid water is found there, raising hopes that such life could exist there and possibly other worlds. However, in a separate study also published in Nature, European astronomers reported the discovery of carbonates around a dying star that, contrary to previously thought, could not have formed in the presence of liquid water. The discovery of carbonates in meteorites, such as the infamous Martian meteorite ALH84001, has been presented as evidence that liquid water, a critical component of life, was abundant in the early solar system. The new discovery does not rule out the formation of carbonates in liquid water, but does show that this is not the only mechanism, and thus carbonates may not be as strong an indicator of hospitable conditions for life as previously thought.

Related Links:

•  Spaceflight Now article
•  SPACE.com article about microbes
•  SPACE.com article about carbonates