From above, the strange-looking circular pit recently found by the Mars Reconnaissance Orbiter (MRO) appears to be etched into the surface of Mars; a concave depression that extends downward into what looks like a relatively flat subsurface. It is here, and in other features on the Red Planet that present access to subterranean levels, that some scientists believe that alien life will be discovered on Mars. One astrobiologist, in particular, sees such features as the “last best place” to find evidence that life once existed on Mars and may perhaps continue to do so.
As reported by Inverse, Dr. Penny Boston is the director of NASA’s Astrobiology Institute, and she has been supporting the argument that signs of life — at least microbial life — on Mars may be found in subterranean features since 1992 when she was the first scientist to propose the idea. And although there has been no definitive evidence uncovered that proves life is, or was once, extant on the Red Planet, volumes of data in the interim decades have provided plenty of evidence that suggests that alien life could have emerged and could still exist on what is now a waterless, thin-atmosphered, irradiated, and basically inhospitable planet.
NASA’s Mars Rovers and the MRO, not to mention probes from other space agencies, have detected dormant volcanoes, lava tubes, deep fissures, declivities, depressions, and evidence of seas, lakes, and rivers. And they’ve found ample evidence of the surface being pocked by meteorites. All of the geological features point to the possibility that Mars could have once supported life, and under optimal circumstances, could still support life.
One such place could be in the aforementioned circular pit (and its sisters) recently discovered in the “Swiss cheese terrain” (carbon dioxide ice on the surface that resembles Swiss cheese) of Mars. At present, according to Space, scientists are not certain whether or not the depressions in the surface are craters or the result of surface collapses.
The MRO took the photo in the southern hemisphere of Mars in what is the planet’s late summer. The image was unveiled by NASA Friday (June 2).
The pits and the other features of Mars that open up the lower subsurface levels of Mars to exploration are, Dr. Boston believes, the “last best place” to find living organisms. She bases her hypothesis on extensive work she has done in regard to Earth caves and subterranean environments.
In a 2015 National Park Service article, Mark Kaufman explained Boston’s reasoning.
“These places are isolated from the severe temperature fluctuations, solar radiation, and suffocating dust storms present on the Martian surface. In short, the subsurface is dramatically more stable – a consistency not unlike the climate inside Carlsbad Caverns, which stays around 56 degrees year round.”
Boston’s research found that microbes consistently thrived in patches that were often predominantly composed of distinct species, regardless of proximity.
“The biodiversity down there is extreme – it’s super biodiverse –one patch of bacteria in Lechuguilla [located in Carlsbad Caverns National Park] might have just a 20 percent overlap with the patch next to it.”
And some of those microbes do not need sunlight and regular nutrients to survive. Called extremophiles, these microbial organisms, unlike life on the Earth’s surface, are able to consume the chemicals in the rock around them and survive.
Boston’s work and ideas pertaining to cave-dwelling microbes have been overshadowed in recent years by all the excitement generated by the ice-encrusted moons of Jupiter and Saturn that are believed to house vast oceans underneath, and the possibility of alien life they may hold. But she remains unperturbed, noting that the moons of Enceladus and Europa are much more cave-like in their environmental make-up than they are oceanic. She points outed that like caves, those worlds are at least partially enclosed and protected from surface, atmospheric, and space conditions.
As of 2015, the various detection probes orbiting and crawling around the Red Planet have uncovered over 300 distinct subsurface features. That is quite a bit of potential environments on Mars where alien life might one day be discovered.
[Featured Image by Helenfield/Shutterstock]