Move On to Mars

Charles Cockell and Vladimir Pletser install dosimeters under gravel rocks during a simulated space expedition on Devon Island, Canada, July 2001.
Credit: ESA

Science fiction writers have long imagined a future for humans on Mars, and Hollywood has created several movie fantasies about what the experience could be like (with a few improbable aliens added for extra drama). NASA has addressed the possibility of creating human colonies on Mars someday, but so far, only robots have stepped foot on the red soil.

How long will we have to wait for science fiction to become a reality? According to Charles Cockell, a microbiologist at the Open University in the UK, humans could go to Mars now.

“Technically, we could go today if we wanted to,” he says, and suggests the reason humans haven’t made the journey yet is because of political concerns. “I think we are ready. As time goes on, we’re going to be more and more ready to go as technology gets better and life support systems improve.”

Artist’s representation of a human mission to Mars.
Image credit: NASA/ David Mattingly and Pat Rawlings

Mars has a thinner atmosphere than Earth, so the surface is more exposed to the sun’s radiation and cosmic radiation from the galaxy. Cockell says human travelers to Mars would have an increased risk of cancer due to this exposure, and also because of the long, 6-month journey out, since spacecraft don’t adequately shield astronauts from radiation. However, he says that we could devise shelters to help mitigate this danger.

“You could get people there and back alive with a small storm shelter on the spaceship,” he says. “It’s not that bad – you sit in a box for a couple of days during a solar particle storm. The habitat for Mars explorers will be an 8-meter diameter tin can anyway.”

The first habitat on Mars will be small, but the first explorers will probably only stay for 500 days before heading back to Earth. Long-term plans for more extensive habitats on Mars are similar to the Biosphere 2 project: a completely contained, closed-loop shelter that has gardens for growing food, recycled water, and other natural systems that use internal resources to support the humans living there.

A model for a future Mars settlement? Biosphere 2 is a 3.15-acre structure originally built to be a closed ecological system, with five areas based on natural biomes, as well as an agricultural area and a human living/working space.
Image credit: University of Arizona

Many scientists are concerned that even with a closed system, a human colony on Mars creates planetary protection problems. Astrobiologists hope to find proof of native life on Mars, and because humans carry with them billions of bacteria, we could end up introducing Earth-life on Mars and corrupting or extinguishing any life that may reside there.

While Cockell agrees we do need to search for indigenous life on Mars, he doesn’t think these planetary protection issues are a major concern.

“Human microbes are not going to survive for very long on Mars anyway – they’ll die very quickly,” he says. “Not a lot of people would agree with my views, but I would just go there and be done with it. It’s not likely that, even if a microbe did grow, it’s going to destroy life on a planetary scale.”

Most scientists think life on Mars would have to be deep underground in order to access the subterranean water and to stay protected from the harsh surface environment. Cockell says this means we have even less to worry about in regards to contaminating Mars.

This representative-color image of Olympus Mons was taken by the Mars Global Surveyor spacecraft. Although three times higher than Earth’s tallest mountain, Mount Everest, Olympus Mons may not be as difficult to climb because it is very broad, with a gradually rising slope.
Image credit: Mars Global Surveyor project, MSSS, JPL, NASA

“On Earth, when you go out to do your shopping, you don’t worry about contaminating the deep subsurface biosphere 3 kilometers underneath the store,” he notes. “That’s my parallel with Mars. We’ve blown up a concern that isn’t really a concern.”

“Even if there is indigenous life, the chance of anything coming off humans or off equipment that’s going to cause planetary scale disruption in the martian biota by finding its way into the subsurface is so remote, it’s not even worth worrying about,” he adds.

Cockell says that, to be prudent, we should try to limit the microbes we bring to Mars, and also catalogue the microbes we know we are taking with us. Still, he doesn’t think too much money or effort should be dedicated to this aspect of exploring Mars. One exception would be if we drilled deep into the martian subsurface.

“Then we would have to be more careful,” he says. “But generally I think we can easily do human exploration on the surface without causing a catastrophe to martian biology. Of course this is all pure speculation, because we don’t know what martian biology would be like, if it’s there at all.”

Cockell’s enthusiasm to send humans to Mars is part of a personal dream to go there himself. In fact, he says he would love to be the first person to cross the martian north pole. He has been to the Earth’s South Pole, traveling with the British Antarctic Survey to study the effects of UV radiation on microorganisms.

“I guess that’s one of the reasons I do studies in extreme environments, because it gives me a connection with Mars,” he says.

In that light, Cockell helped create the Earth and Space Foundation, which funds expeditions that bridge the gap between Earth and space exploration. In addition to funding field work in extreme environments on Earth, the foundation has set up awards for future expeditions on Mars, including one for the first team to reach the summit of Olympus Mons, the largest volcano in the solar system.

“For the summit of Olympus award, we have a piece of rock from the summit of Mount Everest and a plaque,” he says. “We also put $10,000 into a high interest account, and the money will just sit there. In a hundred years time, when someone comes to claim it, the award will be substantial.”