Was there ever life on Mars?
Using data from the Curiosity rover, a University of Calgary (UofC) scientist is studying Mars’ geology “for signs the planet could have once supported life.”
It’s part of the NASA-led Mars Science Laboratory mission to examine the rocks on the surface of Mars, as they could offer evidence of life on the Red Planet.
“Our goal is to place constraints on whether Mars was habitable,” Tutolo said. “And if Mars was habitable, then we can think about whether it actually did evolve life.”
#UCalgary scientist, Dr. Benjamin Tutolo, studies Mars’ geology for signs the planet could have once supported life, using data from the Curiosity Rover https://t.co/dQTRewP5sR @UofC_Science pic.twitter.com/PRtwOCDP3o— U Calgary (@UCalgary) August 12, 2022
The study will be using data collected by Curiosity as it was slowly climbing Mount Sharp 10 years ago to finally land in the centre of the Gale crater.
The rover has analyzed the chemistry and minerology of 1,211 samples of rocks and soil surfaces and sent 2,659 results back to Earth.
Tutolo and his team will do experiments in the laboratory to better understand and interpret the results. They will also conduct field research in British Colombia and run numerical models on a computer.
Study focuses on geological transition of rocks
The team will focus on examining the geological transition of rocks from the oldest layers of sediments to the younger layers “deposited in the crater and which formed Mount Sharp around 3½ billion years” ago.
Tutolo’s study suggests the oldest rocks in the crater are from a lake that is river-fed – “fluviolacustrine environment” –while the younger sediments contain extremely soluble salts – magnesium sulphate salts – such as Epsom salt that can be used for bathing. As these salts are extremely soluble, precipitating them requires all the water to be evaporated.
“We think that it must have been drier on Mars in order to precipitate those minerals. What we’re exploring is how that transition is recorded in the rocks,” Tutolo said.
The research is also taking advantage of the “rare-on-Earth” Basque Lakes near Cache Creek, B.C., that contain magnesium sulphate where the same sulphate minerals found on Mount Sharp on Mars are actively precipitating.
Tutolo is trying 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 levels of oxygen to Earth’s atmosphere, the team is using special tools in the lab to examine sensitive substances in the absence of oxygen, such as an anaerobic chamber that simulates conditions on Mars.
Mars’ geology helps understand Earth’s evolution
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 there’s a potential that life evolved and existed on Mars’ surface at that time. If life did evolve, what evidence can we get from the rocks?
“There was probably a period of time when Mars was getting warm and having water again, and going back and forth (from warmer to colder),” said Tutolo.
He explained that the Earth has experienced ice ages and greenhouse climates as a result of the slight variations in its movement through space, whereas Mars’ movement changes a bit more dramatically, making those cycles more enhanced.
Tutolo also adds that the geological history of early Mars helps understand the history of early Earth as there’s limited access to its geological record from that time.
The limited access to early Earth’s geology is attributed to “plate tectonics whereby, over the eons, the surface gets subsumed into the planet’s mantle as continent-sized slabs of rock collide.”
“But on Mars, all of those rocks have been there since they were deposited, some 3½ billion years or more ago,” Tutolo said. “So we can see those rocks on Mars and understand how life evolved on our planet, going from totally abiotic, or without life at all, to what it is today.”