Water-Rock Reactions Could Be 'Food' for Life on Mars

A new study has shown how low temperature chemical reactions between iron-containing minerals and water could produce hydrogen ‘food’ for microorganisms that inhabit pores and cracks in rocks below the ocean floor and parts of the continents.

Previously, scientists have studied hydrogen production in rocks at temperatures too hot for life. The new study found that similar processes could occur at temperatures where microorganisms can survive. These low-temperature environments are more abundant on Earth, and the study opens up the possibility for a large ecosystem thriving deep below the surface of our planet. The findings also provide clues about the potential for ancient, hydrogen-dependent ecosystems on Mars if iron-rich igneous rocks were once in contact with water.

Another important result for astrobiologists relates to the history of life on Earth. Hydrogen produced by water-rock interactions is thought to be one of the earliest sources of energy for life on Earth.

The study was published in the journal Nature Geoscience under lead author Lisa Mayhew of the University of Colorado Boulder, and former attendee of the Josep Comas i Sola International Summer School in Astrobiology.