Life on Mars?

Ever since Commander Chris Hadfield’s orbital rendition of “Space Oddity”, David Bowie and Canadian space exploration have gone hand-in-spacesuit-gloved-hand. That said (and with all due respect to Cmdr. Hadfield), I’m much more partial to 1973’s “Life on Mars?“.

Obviously, I’m a huge fan and proponent of Arctic science—and now you’ve got me pegged as a space geek as well. You can imagine my excitement when I discovered the myriad ways in which these worlds collide (see what I did there 😉 ).

A barren landscape.

The polar desert of the central Canadian Arctic Archipelago approximates Mars in many respects: take away the snow and plants (look closely, they’re hard to see) and add a reddish tinge to this hill on Somerset Island, and you’d have a very close stand-in. For these reasons, the Canadian Arctic is often used to test new Mars-bound technology, and to investigate the potential for life to exist on other, less hospitable, planets. Image: Paul Sokoloff © Canadian Museum of Nature

Tomorrow, I will begin a two-week rotation as the crew biologist at the Mars Desert Research Station in Huntsville, Utah, USA. While I’m there, I’ll be working on a research project that combines my museum expertise and love of the Arctic with research that will lay the groundwork for the future exploration of other planets. Weeks ago, as I sat down to pound out my research proposal, I was pleasantly surprised with the profile of Arctic organisms in space research.

Collage: Lichens growing on rocks.

Two iconic Canadian Arctic lichens, the map lichen (Rhizocarpon geographicum, right), and the elegant sunburst lichen (Xanthoria elegans, left), have both been studied to determine the limits of their resilience in some of the most extreme environments on—and off—the planet. Image: Paul Sokoloff © Canadian Museum of Nature

Lichens—hardy, slow-growing, and self-sufficient organisms that they are—steadfastly encrust some of the coldest and driest parts of the planets, notably the polar deserts of the Arctic and the Antarctic dry valleys. Unsurprisingly, they make pretty good candidates as organisms that might survive the rigors of interplanetary travel and life on other worlds.

Astrobiology—the interdisciplinary study of life both on and off Earth—experiments have often focused on lichens as model organisms. For example, the humble map lichen, found everywhere from the Gatineau Hills near Ottawa to the top of Ellesmere Island, and elegant sunburst lichen, familiar to tundra-travellers everywhere, have survived exposure to space onboard a Russian space facility as part of the Lithopanspermia experiments. These experiments seek to determine if viable life can be transported from one world to another by meteorites, and indeed, recent experiments on Xanthoria elegans have confirmed that the species (as a model organism), could potentially survive the shock of a meteorite impact.

Two masses placed on a flat rock.

Nostoc commune, sometimes called star jelly, is a cyanobacterium (photosynthetic bacteria). It is found all over the Canadian Arctic, from lush meadows to polar deserts. It’s also really gross. Like, squishy green gelatine gross. To quote my colleague Jeff Saarela on our last research trip: “You really want to press that?” Image: Paul Sokoloff © Canadian Museum of Nature

Cyanobacteria—photosynthetic colonial bacteria that I often encounter as gelatinous green sheets—tough it out in nearly every habitat known to occur on Earth. Some species of this ancient group are endoliths: they grow inside rocks, sheltering themselves from the elements inside stone. Astrobiologists study these endoliths to determine how they change the rock they grow in, and how could we interpret these signatures as we look for life on other worlds. One genus, Spirulina, has even been proposed as a food source for astronauts on long-term space missions.

Finally, their ability to resist desiccation and radiation, alongside their ability to make their own energy and fix their own nitrogen from the atmosphere (very few organisms can do this!), make cyanobacteria an attractive candidate for possible transplantation to Mars.

Collage: A barren, rugged landscape, lichen growing on a rock, moss on a rock, a flowering plant.

Ethical and technological considerations aside (how does one build a magnetosphere?), should we ever decide to terraform Mars, the organisms introduced to the nascent ecosystem would likely come from Earth’s polar regions—they come pre-adapted to the cold. Much literature on Martian terraforming portrays the process as analogous to succession (ecosystem recovery post-disturbance) in the Arctic, where bare rock gives way to (clockwise from upper left) lichen, bryophyte, and vascular-plant-dominated communities. Images: NASA © Public domain, Paul Sokoloff © Canadian Museum of Nature

This brings me to one of the most interesting aspects of astrobiology: the potential for terraforming other worlds. Could we build a functioning, Earth-like ecosystem on an inhospitable world? Much of the theoretical work on this subject has looked at transforming the face of Mars, and I have to admit that I’ve been fascinated by the possibility of living on the red planet ever since reading Kim Stanley Robinson’s excellent Mars novels.

Firstly, if we were to ever terraform Mars, there would be decisions to make: Is this the right thing to do? Do we have the right to alter another world at such a fundamental level? What if we find life already there? Assuming we do decide to go ahead, it would be a massive undertaking—not only would we have to alter the composition of the atmosphere and the surface temperature, but there is also the issue of increasing the insolation (sunlight received at the surface), and protecting against radiation (note to self: never take the magnetosphere for granted).

Assuming that these conditions are met (and I’m greatly simplifying here), then we could start building the ecosystem, bit by bit. Like biological Lego (I kid, I kid). An overview of the process is provided in papers by James Graham (474 Kb PDF) and Chris McKay (read the abstract).

At its core, terraforming would start at a fundamental level, introducing bacteria and other microbial life, followed by lichens and hardy cyanobacteria, then bryophytes, and eventually hardy vascular plants—like those the museum studies in the Canadian Arctic.

I’ve always felt that traveling to the Arctic is a bit like traveling to a different planet, but the idea that the work we do here at the museum—specifically, cataloguing the biota of the Arctic—could in some small way contribute to the science that gets our species to other worlds, well, that’s just too cool for words.

Wondering what Paul is doing at the Mars Desert Research Station? Read his previous article: Trading My Plant Press for a Space Suit.

This entry was posted in Arctic, Fieldwork, Plants and Algae, Research, Tools of the trade and tagged , , , . Bookmark the permalink.

One Response to Life on Mars?

  1. Pingback: Plants for Mars | yukunerkblog

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