Recent research suggests that there’s a chance of finding life on Mars if scientists go beyond exploring the surface and take a closer look at the planet’s underground.
According to a report from Live Science, research presented Tuesday at the American Geophysical Union’s annual meeting suggests the possibility of microbial life existing in the Martian underground. While previous Mars missions had focused on sites on the surface where ancient seas are thought to have existed billions of years ago, the scientists behind the new research believe Mars might have something similar to Earth’s deep biosphere, which is an underground environment in our planet known for the many microorganisms within it.
Speaking to Live Science, University of Hong Kong Department of Earth Scientist associate professor Joseph Michalski, who discussed his findings at the AGU meeting, said that Mars likely had a surface similar to Earth when both planets were still young. Things changed, however, when the Red Planet lost its magnetic field and became exposed to extreme radiation, thus making it hard for life to exist on the planet’s surface. He added that life might have already started appearing on Mars before this event, possibly as far back as about 3.8 billion to 3.9 billion years ago, around the same time the first signs of life on Earth had appeared.
As explained by Michalski to Live Science, the Martian environment at that time was very similar to the hydrothermal settings found in some parts of present-day Earth. He believes that the first Martian microorganisms could have thrived in those settings, then adapted to life in the subsurface “for quite a long time.”
Given the conditions of microbial life in Earth’s deep biosphere, where it is thought that these creatures make up close to half of all life on our planet, Michalski also believes there’s a chance Mars’s underground could be home to a similarly “rich and diverse” set of microbial communities. He told Live Science that the role of deep biosphere microbes in preventing carbon from reaching the surface and becoming a greenhouse gas could help scientists further “understand the origins and evolution” of life.
“We’re at a point now where it’s truly a frontier of understanding what ‘deep biosphere’ truly means on Earth, and how that relates to exoplanets and other planets in our solar system. It’s a window into our own origins.”
Compared to Earth’s deep biosphere, the Martian underground could be more habitable due to a number of reasons, Michalski added. He explained that there could be single-celled organisms that could survive for a long time by metabolizing various gases, as the porous qualities of Mars’s subsurface rock allow for a freer exchange between gas and nutrients, while the fact Mars’s core is cooler than Earth’s allows for more “hospitable” temperatures for these organisms to live in.