Three years after discovering evidence of water on Mars, Nilton Renno, a University professor of Atmospheric, Oceanic and Space Sciences, is looking for life on the planet.
Renno is leading a $1 million NASA-funded project to determine if liquid water can exist on Mars and whether that water can sustain life.
In 2008, Renno was the co-investigator of the Phoenix Mars Mission — a NASA project led by a group of University researchers — that found evidence of liquid brine on the surface of Mars by analyzing soil and photos of the planet. The discovery was the first of its kind and raised questions about whether Mars, which has extremely low air pressure and drastic temperature swings, could sustain life.
According to Renno, the first step of his current project is replicating the conditions on Mars — that the mission’s lander experienced in the 2008 project — to further explore whether the existence of liquid water on the planet is possible. However, according to Rackham student Harvey Elliott, a Ph.D. candidate in the AOSS department, the liquid water on Mars is very different from water on Earth.
“Pure water would either evaporate or sublimate directly from ice to gas on Mars,” Elliot said.
A member of Renno’s team, German Martinez, who is a research fellow in the AOSS department, said brine — a liquid combination of water and highly concentrated salt — could exist in Mars’s environment because of its unique anti-freeze properties.
“Brines make the freezing point of water drop,” Martinez said. “It’s like when we add salt to streets to melt snow.”
Elliot is currently designing the experimental chamber where Mars-like conditions will be replicated. The researchers plan to create a chamber with temperatures as low as -120 degrees Celsius and extremely low pressures, using the same Martian soil composition found in the Phoenix landing site, Elliot said.
Though Renno said he is confident his team will be able to replicate brine in Mars-like conditions, he said he is uncertain about the success of the second portion of his project, which is to determine whether or not the brines can sustain life.
He added that it is common for brines to support life on Earth in places such as deserts and dry lakes.
“If you go to Death Valley, there are dry lakes that have brine water. There are shrimps, called brine shrimps, that can survive in these places,” he said.
But Renno said examples of life flourishing in brines on Earth do not necessarily mean life can exist in brines on Mars.
“On Earth, (microbes) would be at much higher temperatures than on Mars … some of the salts we found on Mars can be liquid at -70 degrees Celsius. The challenge for us is finding microbes that can survive in brines at Mars-like temperatures,” Renno said.
But Elliot said even if the team finds evidence that microbes could survive in brines in Mars-like conditions on Earth, it’s a “jump” to assume that microbes actually exist on Mars. He added that if the researchers discover any evidence of microbes surviving in brines in Mars-like conditions, the finding would potentially fuel a new generation of space missions to Mars.
“We would need more rovers, landers, more missions to the polar regions. If you want to find life on Mars, you need to go there,” Elliot said.