If life exists or has ever existed on Mars, it’ll likely require a small but vital set of ingredients. A new study, published in the journal Icarus, suggests that one vital element of this equation – organic matter – rains down on the rusty surface all the time.
According to the paper, Mars’ frankly rubbish atmosphere and its irradiated surface means that organic matter on the surface won’t last particularly long. That means, then, that “the recently discovered organics in the Martian subsurface and atmosphere” – courtesy of our robot friends – “were probably delivered in geologically recent times.”
The SRON Netherlands Institute for Space Research-led team has suggested that possible deliverers of such organic goodness include comets, interplanetary dust particles, and carbon-rich (carbonaceous) asteroids – and, in order to back up their assertion, they engaged in a little bit of modelling using a supercomputer named Peregrine.
Based on reasonable assumptions about the amount of organics present in said delivery mechanisms, and similar assumptions as to the average rate they’d arrive on Mars, their simulations threw up some intriguing numbers. Via interplanetary dust, for example, you’d expect the Red Planet to get between 70 and 300 tonnes of organic matter per year.
Cometary impacts, on the other hand, deliver 13 tonnes of organic material per year, whereas asteroid impacts – which occur magnitudes more frequently than their icy brethren’s collisions – drop around 50 tonnes per year.
All in all, then, it appears organic matter is, give or take, continuously raining down on Mars. So what exactly does this mean for the prospects of life over there?
Importantly, organic material doesn’t automatically mean that there are biological entities there, even if there’s tonnes of it dropping from the heavens.
Although we aren’t yet sure how organic material develops into life, we’re acutely aware that it’s not simply a matter of smushing organic material together and hoping for creation to spring forth. Water to some degree seems important, as does shielding from radiation and a suitable atmosphere. Chemical compounds that life can use to break down and produce energy is also a necessity.
“Ironically, protection from asteroid strikes may also be important, too many asteroid strikes on the planet’s surface may reduce the ability to support life,” Dr Ben Libberton, a microbiologist at the MAX IV Laboratory in Lund, Sweden, who was not involved in the paper, told IFLScience.
In any case, “we can't explain the organic material on earth without life,” Libberton added. “The fact that the organic material on Mars can be explained by asteroid strikes could be interpreted as a little disappointing.”
Still, when it comes to life, showers of organic matter certainly aren’t unwelcome – and this applies to realms other than our slightly crimson, dusty neighbor.