Was there ever life on Mars? Using data from the Curiosity rover, a University of Calgary (UofC) scientist is studying the geology of Mars “for signs that the planet could once have supported life.” Dr. Benjamin Tutolo, associate professor of geosciences at the UofC, will conduct a three-year study funded by the Canadian Space Agency. It is part of the NASA-led Mars Science Laboratory’s mission to examine rocks on the surface of Mars as they could provide evidence of life on the Red Planet. “Our goal is to put constraints on whether Mars was habitable,” Tutolo said. “And if Mars was habitable, then we can think about whether life actually evolved.”
#UCalgary scientist Dr. Benjamin Tutolo, studies the geology of Mars for signs the planet could once have supported life, using data from the Curiosity Rover @UofC_Science pic.twitter.com/PRtwOCDP3o — U Calgary (@UCalgary) August 12, 2022 The study will use data collected by Curiosity as it slowly climbed Mount Sharp 10 years ago to finally land in the center of Gale Crater. The rover analyzed the chemistry and mineralogy of 1,211 rock and surface soil samples and sent 2,659 results back to Earth. Tutolo and his team will conduct experiments in the laboratory to better understand and interpret the results. They will also conduct field research in British Columbia and run numerical computer models.
The study focuses on the geological transition of rocks
The team will focus on examining the geological transition of rocks from the oldest sedimentary layers to the youngest layers “that were deposited in the crater and formed Mount Sharp about 3½ billion years ago.” Tutolo’s study suggests that the oldest rocks in the crater come from a river-fed lake—a “fluviolacustrine environment”—while the younger sediments contain highly soluble salts—magnesium sulfate salts—like Epsom salt that can be used for bathing. As these salts are highly soluble, their precipitation requires evaporation of all the water. “We think it must have been drier on Mars for these minerals to have precipitated. What we’re investigating is how this transition is recorded in rocks,” Tutolo said. The research is also exploiting the “rare on Earth” Basque lakes near Cache Creek, BC, containing magnesium sulfate, where the same sulfate minerals found at Mount Sharp on Mars are actively precipitating. Tutolo tries to answer this question: “Is there a point where it gets so salty that nothing could live there?” Since Mars is red as a result of all the iron on its surface, where its atmosphere doesn’t have similar oxygen levels to Earth’s, the team uses special tools in the lab to look at sensitive substances in the absence of oxygen, such as . an anaerobic chamber that simulates conditions on Mars.
The geology of Mars helps to understand the evolution of Earth
Understanding the geological transition on Mars will provide information on whether the planet’s environment would still be habitable in drier and colder environments, and whether life might have evolved and existed on the Martian surface at that time. If life evolved, what evidence can we get from rocks? “There was probably a period of time when Mars warmed and had water again and went back and forth (from warmer to cooler),” Tutolo said. He explained that the Earth has experienced ice ages and greenhouse climates as a result of slight fluctuations in its motion through space, while the motion of Mars changes a little more dramatically, making these cycles more amplified. Tutolo also adds that the geological history of early Mars helps to understand the history of early Earth as there is limited access to its geological record from that time. Limited access to Earth’s early geology is attributed to “plate tectonics where, over eons, the surface sinks into the planet’s mantle as continent-sized slabs of rock collide.” “But on Mars, all these rocks have been there since they were deposited, about 3.5 billion years ago or more,” Tutolo said. “So we can look at these rocks on Mars and understand how life on our planet evolved, going from completely abiotic or lifeless to what it is today.”
