University of Alberta professor helps NASA search for life on Mars

         

A University of Alberta planetary geologist is helping NASA answer one of the most important questions in human history — are we alone in the universe?

Chris Herd is the only scientist in Canada among the large group of international experts advising the American space agency on how to run the Mars rover being launched in 2020.

The car-sized device will travel up to 20 kilometres across the red planet’s surface, equipped with a drill that can collect core samples of the most promising rocks and soils and leave them in a cache.

One of the mission’s main goals is to explore what conditions were like in the ancient past and search for fossilized signs of microbial life, says Herd, a professor in the earth and atmospheric sciences department.

“People have looked at what type of samples should be brought back to answer the big questions about Mars. The ultimate question is ‘Was there ever life there?'”

The rover, which will join the Opportunity and Curiosity rovers NASA sent to Mars on earlier missions, will also test a method for producing oxygen in preparation for possible future human visits.

Herd was one of 11 people picked last year out of 80 applicants to sit on the return sample science board, which is advising how material the machine picks up should be collected and stored.

It’s too expensive to bring the approximately half-kilogram of samples back on the same spacecraft for analysis on Earth, so the material will be kept in tubes for years until a “fetch rover” is sent to retrieve it.

One of the first questions given to the return sample board was how much heat specimens can endure, both from natural sources and drilling, without destroying their scientific value.

The team of mineralogists, organic chemists and other experts concluded temperatures shouldn’t exceed 50 C, so the tubes will have a reflective coating to ensure that doesn’t happen.

One reason Herd, 42, is involved in the project is that he studies meteorites from Mars.

While these space rocks are an important source of data, it’s difficult to tell where on the planet they come from. He’s keen to learn about the planet’s geological evolution from samples taken at known locations.

Among other benefits, that information would provide crucial context if any evidence turns up that there was once microscopic life on Mars.

“It appears to have gone through a big shift, from having liquid water under the surface that was neutral, so good for life, but about four billion years ago it became more acidic and less hospitable to life,” Herd says.

“We don’t really know why that happened.”

He thinks it’s unlikely living organisms will be found on a planet bathed in radiation that’s mostly sterile up to 50 centimetres below the surface. But, just in case, NASA has a separate group looking at how to protect Earth and Mars from each other’s bacteria.

Herd will attend a February meeting in Pasadena, Calif., intended to narrow the list of eight possible landing sites to three.

He’s thrilled to be involved in the project, saying he started dreaming of working on rocks from Mars when he was about 13 years old.

This work could give insight into a range of important scientific issues, including the likelihood that anyone else is out there.

“If we find the right location and get the right rocks, we can address this question of whether life ever existed on planets other than our own,” Herd says.