Scientists have concluded that Ancient Mars may have met all the necessary conditions for life as we know it to develop beneath the surface.
A new study has discovered that more than enough chemical energy existed through the Martian subsurface region in order to allow microbial colonies, just as those here on Earth, to exist and thrive on the Red Planet.
Despite the fact that sunlight may not have reached such areas, the new study argues that an abundance of dissolved hydrogen, which acted as an electron donor allowed microbes to survive beneath the Martian surface.
Speaking about the new study, Jesse Tarnas, a graduate student at Brown University said: “We showed, based on basic physics and chemistry calculations, that the ancient Martian subsurface likely had enough dissolved hydrogen to power a global subsurface biosphere.”
“Conditions in this habitable zone would have been similar to places on Earth where underground life exists.”
Jesse Tarnas is the lead author of a study published in Earth and Planetary Science Letters.
Here on Earth, microbes thrive beneath the surface in areas known as SLiMES, or subsurface lithotrophic microbial ecosystems.
As explained by experts, microbes living in such colonies do not obtain their energy directly from the sun, but instead by peeling electrons from molecules that exist in their environment.
And as experts say, in most cases, dissolved molecular hydrogen is what provides the living organisms with fuel.
Radiolysis and Life on Mars
Scientists argue that radiolysis may have been the process responsible for creating the necessary hydrogen beneath the Martian surface for life to exist.
And if it existed, life on Mars may have been present beneath the surface some 4 billion years ago, when the red planet’s crust was most likely home to a wide range of hydrogen concentrations known to support microbial life on Earth today.
As explained by experts, this doesn’t mean life definitely existed, but it provides us with the necessary facts to suggest it may have.
“The question then becomes: What was the nature of that subsurface life, if it existed, and where did it get its energy,” explains Jack Mustard, a professor in Brown’s Department of Earth, Environmental, and Planetary Sciences.
“We know that radiolysis helps to provide energy for underground microbes on Earth, so what Jesse did here was to pursue the radiolysis story on Mars.”
Jesse’s study included analyzing data obtained from the gamma-ray spectrometer on NASA’s Mars Odyssey spacecraft.
The study also used geothermal and climate models to see where life may have thrived, discovering the habitable zone on Mars was most likely several kilometers thick.
Furthermore, the team concluded based on various climate scenarios that colder environments on Mars may have been more suitable for hosting life.
“People have a conception that a cold early Mars climate is bad for life, but what we show is that there’s actually more chemical energy for life underground in a cold climate,” Tarnas explained.
“That’s something we think could change people’s perception of the relationship between climate and past life on Mars.”
Featured Image Credit: via European Space Agency – ESA on GIPHY