Biosignatures & Paleobiology: January 2007

Using atmospheric chemical models of a Snowball Earth, scientists from NAI's Alumni Virtual Planetary Laboratory Team show that, during long and severe glacial intervals, a weak hydrological cycle coupled with photochemical reactions involving water vapor would give rise to the sustained production of hydrogen peroxide. The peroxide, upon release from melting ice into the oceans and atmosphere at the end of the snowball event, could mediate global oxidation events. Their results are published in the December 12th issue of PNAS. [Source: NAI Newsletter]

Production of hydrogen peroxide in the atmosphere of a Snowball Earth and the origin of oxygenic photosynthesis, PNAS