Rocks in the Martian crust may produce the same chemical energy as deep microbes on the Earth’s surface, new research suggests. NASA’s Perseverance has begun searching the surface of Mars for ancient life. Now, a new study suggests that the Martian underground may be a good place to look for modern life that may exist on the red planet.
The study, published in Astrobiology, analyzed the chemical composition of Martian meteorites. The results suggest that if the rocks had been in contact with water, they would have produced the chemical energy needed to support the microbiome, just as those that lived in the depths of the planet without light. Because these meteorites may represent large areas of the Martian crust, these findings suggest that much of the Martian underground may be habitable.
Jesse Tarnas, an experimenter at NASA’s Jet Propulsion Laboratory and the study’s lead author, said the significance of the results of the science of underground exploration is that as long as there is groundwater on Mars, there is likely to be enough chemical energy to support underground microbial life: “We don’t know if there was ever an origin of life beneath the surface of Mars, but if there is, we think there will be enough energy there to sustain life to this day.” ”
In recent decades, scientists have discovered that deep in the region is home to a vast biome that is largely separate from the world above. In the absence of sunlight, these organisms depend on the byproducts of chemical reactions produced when rocks come into contact with water.
One of the reactions is radioactive decomposition, in which radioactive elements in rocks react with water in pores and fissure spaces. This reaction breaks down water molecules into their constituent elements hydrogen and oxygen. The released hydrogen dissolves in the remaining groundwater, while minerals such as ferrite absorb free oxygen to form sulfate minerals. Microbes can use dissolved hydrogen as fuel and “burn” them using oxygen stored in sulfates.
Researchers have found these “sulfate reduction” microbes in places like Kidd Creek Mine in Canada, where water hasn’t seen sunlight for more than a billion years. Tunes have been working with a team led by Jack Mustard, a professor at Brown University, and Barbara Sherwood Lollar, a professor at the University of Toronto, to better understand these underground systems and look for similar habitats on Mars and elsewhere in the solar system. Their project called Arthur 4-D: SubSurface Science and Exploration is funded by the Canadian Institute of Advanced Research.
In the new study, researchers wanted to see if there were any components of habitats on Mars driven by radioactive decomposition. They used data from NASA’s Curiosity rover and other orbiting spacecraft, as well as component data from a group of Martian meteorites.
Researchers are looking for components of radioactive decomposition on Mars: radioactive elements such as thorium, uranium, and potassium, vulcanized minerals that can be converted into sulfates, and enough pore space in rock cells to trap water. The study found that in several different types of Martian meteorites, all are rich enough to support earthlike habitats. This is especially true for weathered corner gravel. Weathered angular gravel is a meteorite from more than 3.6 billion years of crustal rock that is more likely to sustain life. Unlike Earth, Mars lacks a plate tectonic system that continuously recycles crustal rocks. So these ancient terrains are largely undisturbed.
The researchers say the findings could help inform an exploration plan to find signs of life underground on Mars. Previous studies have found evidence of active groundwater systems on Mars, and they have reason to believe that groundwater still exists, the researchers said. A recent study suggesting, for example, that an underground lake may lurk beneath the ice sheet in southern Mars, suggesting that as long as there is groundwater, there is life energy.
Tarnas and Mustard say that while there are certainly technical challenges of underground exploration, they are not as insurmountable as one might think. Mustard said the drilling operation on Mars does not require a Texas-sized oil rig, and that recent advances in small drilling probes could soon reach the depths of Mars.
“The underground is one of the frontiers of Mars exploration,” Mustard said. But if we want to consider the possibility that life exists now, below the surface is the place where life is active. ”