All Martian Water May Be Stuck Underground

A team of astronomers from the Brown University, in Providence, Rhodes Island, says that the current interpretation of geological data collected from Mars may be wrong. The experts propose that the vast majority of water that once flowed on the surface of the Red Planet can still be found underground.

This new idea clashes head-on with existing assumptions about what happened. Current theories hold that most of the water is either trapped in ice sheets at the poles, or was removed from the planet altogether, when its atmosphere was largely destroyed by a yet-unexplained phenomena.

The new proposal has significant implications for finding life on the Red Planet, as well as for the quest to establish the locations where space missions would have the highest chances of doing so. The study also implies that any potential life on the planet may have in fact developed underground.

These conclusions are based on years of mineral-mapping data, which have constantly revealed that liquid water only existed on the surface of Mars for short periods of time. Mineral analyses also indicate that most of the rocks that need water to form developed underground.

Data the team analyzed in this investigation covered about 350 locations. All of them displayed signs of minerals that were produced under the surface, but only some had rocks that were made at the surface.

“The types of clay minerals that formed in the shallow subsurface are all over Mars. The types that formed on the surface are found at very limited locations and are quite rare,” adds Brown professor John Mustard, who is also the coauthor of a new study detailing the findings.

The paper is published in this week's issue of the top scientific journal Nature. Geological data were collected by rovers and orbiters belonging both to NASA and the European Space Agency (ESA).

In other theories, water existed on the surface of Mars for prolonged periods of time. However, this would imply that the planet's atmosphere had to had been thicker than current data indicate. In order for these explanations to hold true, experts needed to discover a mechanism capable of removing some of the atmosphere from around the planet.

“If surface habitats were short-term, that doesn't mean we should be glum about prospects for life on Mars, but it says something about what type of environment we might want to look in,” explains the lead author of the new investigation, Bethany Ehlmann.

“The most stable Mars habitats over long durations appear to have been in the subsurface. On Earth, underground geothermal environments have active ecosystems,” adds the expert.

She holds joint appointments, as an assistant professor at the California Institute of Technology (Caltech) and as a research scientist at the NASA Jet Propulsion Laboratory (JPL), both in Pasadena.