|Bacteria in the low-oxygen fluids of an abandoned mine created these zinc sulfide spheres. Like most other mineral particles assembled by microbes, these have a consistent size, shape, and chemical composition.|
One of the most promising planetary colonizers comes in the form of cyanobacteria. The ancient bacteria helped create a habitable Earth with oxygen at least 2.5 billion years ago, and have since colonized practically every possible environment while relying upon photosynthesis to convert sunlight into energy.
Cyanobacteria and other rock-dwelling microbes also have proven that they can survive the hard vacuum of space aboard facilities such as Europe's BIOPAN exposure platform and the International Space Station's EXPOSE platform. Only the harsh space radiation in low Earth-orbit presents a life-threatening problem for the hardy organisms.
"Theyre quite capable of tolerating extreme conditions," said Charles Cockell, a geomicrobiologist at The Open University in the UK. "But we were surprised at their abilities to tolerate some conditions such as vacuum."
Fortunately, cyanobacteria won't have to endure quite such harsh conditions on Mars.
Mining extraterrestrial rocks
We already use microbes to help extract materials on Earth, including over 25 percent of the world's copper supply. Microbes could serve a similar purpose on other planets to mine resources, save on rocket fuel needed to launch such resources from Earth, and perhaps make a human base more self-sustaining, Cockell said.
Attack of the Rock-Eating Microbes!