New Method To Find Life On Mars Proposed, Relies On Alien DNA

Is there life on Mars, our planetary neighbor which has been the subject of much study because it once harbored an atmosphere and liquid water that could have potentially sustained life as we know it? We still don’t know the answer, but we keep looking for signs of life — whether past or present — on the red planet.

To do so, instruments aboard existing and future rovers, like NASA’s Curiosity or Mars 2020 and the European Space Agency’s ExoMars, rely on methods that test samples to identify biosignatures — telltale signs of lifeforms that left them behind. But a new technique proposed by researchers from McGill University, Canada, takes the investigation for alien life a step forward, by searching directly for life itself, and not just its indicators.

“The search for life is a major focus of planetary exploration, but there hasn’t been direct life detection instrumentation on a mission since the 70s, during the Viking missions to Mars. We wanted to show a proof-of-concept that microbial life can be directly detected and identified using very portable, low-weight, and low-energy tools,” Jacqueline Goordial, one of the authors of a new study outlining the new method, explained in a statement Friday.

Goordial and her colleagues created what they call a “life detection platform” using a number of miniature instruments, put together in a modular way. This platform can “culture microorganisms from soil samples, assess microbial activity, and sequence DNA and RNA,” according to the statement.

The ability to successfully detect nucleic acid, which forms the basis of all life as we know it, is what makes detection of life by this system unambiguous, unlike other indirect indicators. For doing so, it relies on a miniature portable DNA sequencing device called Oxford Nanopore MiniON.

“The presence of DNA alone doesn’t tell you much about the state of an organism, however — it could be dormant or dead, for example. By using the DNA sequencer with the other methodology in our platform, we were able to first find active life, and then identify it and analyze its genomic potential, that is, the kinds of functional genes it has,” Goordial said.

The active life her team found was in Arctic Circle in Canada, about 900 kilometers from the North Pole, which is where the team carried out its tests. The location was chosen for its cold and dry environment, and its harsh terrain that only harbors extremophile microorganisms, extreme features that make it suitable as a Mars analog. But a Mars analog is still quite a ways from being Mars, as the researcher were well aware.

“Humans were required to carry out much of the experimentation in this study, while life detection missions on other planets will need to be robotic. The DNA sequencer also needs higher accuracy and durability to withstand the long timescales required for planetary missions,” Lyle Whyte, another of the study’s authors, said in the statement.

So the system is not ready just yet to make a foray into space, but it has factors in its favor for if and when it does. It is lightweight and small, which would make it easy to send it to relatively distant destinations, like Jupiter’s moon Europa and Saturn’s moon Enceladus, both among the primary targets in our hunt for life within the solar system.

Titled “In Situ Field Sequencing and Life Detection in Remote (79°26′N) Canadian High Arctic Permafrost Ice Wedge Microbial Communities,” the study appeared online Saturday in the journal Frontiers in Microbiology.