Although no definitive proof of life on Mars has as yet been detected, research into the idea that the Red Planet may have once hosted life (and still might do so in the form of subterranean organisms) is ever ongoing. New research is now suggesting that volcanic activity on ancient Mars may have been conducive to the formation of a habitable environment, perhaps even producing "prebiotic organic compounds" (think: amino acids) that could have made life possible.
As Seeker recently reported, it is not difficult to contemplate a scenario where, at least at some point in Mars' distant past, volcanic activity may have been widespread and a major factor in environmental changes concerning the subsurface, surface, and atmosphere of the planet. Mars is dotted with enormous volcanoes. Olympus Mons, which is the tallest planetary mountain yet discovered in the Solar System (only Rheasilvia on Asteroid Vesta might be taller), is three times the height of Mount Everest on Earth and is the crown jewel of the string of volcanoes that make the Tharsis ridge. Active volcanoes, which would have emitted gases such as carbon monoxide and sulfur into Mars' early atmosphere, could have produced habitable conditions that may have sustained life.
Such conditions may have given rise to microbes, according to research published in Icarus. This could have been achieved via the volcanoes' eruptions altering Mars' atmosphere into a more anoxic covering, one that would have reflected lower oxygen levels and produced fewer oxygen-based reactions. Less oxygen may have contributed to the formation of amino acids, which are basic building blocks for proteins and, by extension, organic life.
The paper explained, "These results imply that ancient Mars should have experienced periods with anoxic and reducing atmospheres even through the mid-Amazonian whenever volcanic outgassing was sustained at sufficient levels. Reducing anoxic conditions are potentially conducive to the synthesis of prebiotic organic compounds, such as amino acids, and are therefore relevant to the possibility of life on Mars."
Seeker reached out to Stephen Sholes, a Ph.D. candidate in earth and space sciences and astrobiology at the University of Washington and the lead author on the Mars paper, who elaborated by email on how the atmospheric conditions on ancient Mars could have been analogous to conditions that produced life on ancient Earth.
"This is important from an astrobiology standpoint because these reducing anoxic conditions have been hypothesized as being important to the origin of life on the early Earth."
Sholes further explained that the research, by constructing a model of the volcanism, gives researchers quantitative data on just how the volcanic activity (and how much of it) was required to produce the anoxic levels. This is a departure from earlier research that simply dealt with volcanism as a geological aspect. Not only does his work indicate what it would take to reach said levels, but the research also looks at whether or not attaining the conditions is possible. Just as important: The research suggests how this can be detected.
Sholes pointed out that the research also was different in that his work searched for answers to the life on Mars question by proposing a connection with volcanic outgassing where most research connected the ancient volcanic activity with the warming of the planet to produce habitability.
"Yes, you need liquid water, but you also need appropriate conditions for life, and here we are finding that the volcanoes should have changed the atmosphere enough to be more conducive to forming complex bio-important molecules," he said.
Sholes' paper is the latest to suggest the viability of an atmosphere on Mars that could sustain at least microbial life. In fact, astrobiologists at the Arkansas Center for Space and Planetary Sciences at the University of Arkansas in Fayetteville announced findings in January that microbes, if presently extant on Mars, could survive the extremely thin atmosphere that now envelopes the planet.
[Featured Image by Nostalgia for Infinity/Shutterstock]