Is or was there life on Mars? That is one of the biggest and most hotly debated questions in planetary science. The manner in which the evidence has been searched for is also a topic of much discussion. The Viking landers in the 1970s were the first to look for direct evidence for microbial life still existing in the Martian soil, and the results are still regarded as inconclusive, with both pro and con supporters debating whether the landers actually found living microbes or just unusual soil chemistry. Subsequent lander and rover missions have focused more on determining whether conditions in Mars’ ancient past were habitable and able to support life as we know it, rather than searching directly for evidence of past or present life itself.
But now a new concept has been proposed, a simple but novel way in which that search could now be continued. ExoLance would try to find Martian microbes by using penetrator probes which would dig deep into the ground and conduct life detection experiments – basically like shooting darts at Mars, hence the name. It might be just what is needed to help answer the question of whether Mars was ever home to life of some kind.
The subsurface of Mars is considered to be the best place to look for life, as it is better protected from the harsh ultraviolet light, thin atmosphere, and cold temperatures on the surface. Deep down where its warmer, there might still be moisture or even aquifers of liquid water. But even just a few feet below the surface would be much better than the conditions on top.
ExoLance, a project of Explore Mars, would use multiple lightweight penetrator probes, or “darts,” to be released from a main lander, or “quiver”; they would hit the surface and then release a transmitter to communicate with an orbiter. Each penetrator would be equipped with life-detection equipment, to be delivered to the subsurface by the penetrator kinetically drilling down about five or more meters. The penetrators are based on military “bunker-busting” technology.
ExoLance would look for signs of active microbial life just like Viking did, but with more advanced experiments. From the introduction page on the ExoLance website:
“The system involves a metabolic test that clearly distinguishes non-living chemistry from the chemistry produced by the metabolism of living microorganisms . What makes this experiment even more intriguing is that if it detects life, it may also be able to determine whether that life is related to life on Earth or is a new strain of life – a separate ‘genesis.’”
By sending multiple penetrators to different locations, the odds are increased of getting valuable scientific data returned, as well as having some penetrators successfully dig down even if some fail to work properly.
According to Chris Carberry, executive director of Explore Mars: “One of the benefits of doing this mission is that there is less engineering. With penetrators we can engineer them to get what we want, and send it back to an orbiter. We can theoretically check out more than one site at a time. We could drop five or six, which increases the chances of finding something.”
Right now, ExoLance is still a concept, with a crowd-funding page on Indiegogo, and is seeking $250,000 in funding. Once the funding is, hopefully, secured, the first prototypes will be built within 12-14 months and tested in the New Mexico desert. After that, NASA and other space agencies will be approached, as well as commercial providers about including ExoLance on a future Mars mission.
ExoLance will be developed in two phases: Phase 1 focuses on the hardware and delivery system, while Phase 2 will focus on the microbial life detection experiments. The project includes some well-known names in astrobiology and planetary science, such as Dr. Christopher P. McKay and Dr. Gil Levin, among others.
For those who have been advocating a return mission to Mars with the specific task of looking for life, ExoLance may be the answer. As mentioned, it will need to piggyback on another spacecraft, whether from NASA, ESA, or someone else, but with a simple, straightforward design and low costs it seems it would be well worth the effort. One of those “darts” may just be able to find something that scientists have been earnestly looking and hoping for: life on Mars.
This article was first published on AmericaSpace.