When it comes to geological processes, Earth and Mars have a lot in common, including a history of seismic activity. Now, new research suggests the sites of 'Marsquakes' could be a good place to begin looking for evidence of life on the red planet.
An international team of scientists that included Nigel Blamey, an assistant professor in the Department of Earth Sciences at Ontario's Brock University, analyzed rock samples from ancient meteorite impact craters and seismic zones in Scotland, South Africa and Sudbury, Ont., and confirmed that the friction caused by major seismic events produces rock containing hydrogen — a potential food for simple life forms.
So-called "hydrogenotrophs" — organisms that are able to metabolize hydrogen as an energy source — were among the earliest forms of life on Earth and still exist deep in its crust. Blamey and fellow researchers Sean McMahon and John Parnell from the University of Aberdeen, Scotland, say their findings, published this month in the journal Astrobiology, indicate there's a good chance the conditions that could support hydrogenotrophs are also present beneath the surface of Mars.
"If we want to find life on Mars, we need to look for two things: water and an energy source," Blamey explains. Last year, NASA scientists confirmed the presence of liquid subsurface water on Mars; the Aberdeen study suggests that the best place to look for an energy source — in this case, hydrogen — would be in faults and craters similar to those the researchers analyzed on Earth.
"Marsquakes will certainly fracture the rock, and there’s potential there for hydrogen, so from our perspective, this is one of the targets that could possibly be used to go looking for life," Blamey says.
The Aberdeen study zeroed in on pseudotachylite, a type of glass-like rock formed by intense friction, for example from a powerful earthquake or meteorite impact. Pseudotachylites from the three study sites were consistently found to contain more hydrogen than other rocks in the control group — the more friction there had been, the more hydrogen.
The tectonics of Mars are still a matter of debate, but McMahon, the study's lead author, says it's likely pseudotachylites would be present around the many cracks and craters in the planet's rocky surface.
In 2018, NASA plans to launch its Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission, which will study the deep interior of Mars. Blamey says his team is hopeful NASA will consider their research when selecting targets for investigation.