If the gigantic structures for excavating extraterrestrial soil are still science fiction scenarios, space mining is already a reality in small matchbox-sized structures aboard the International Space Station (ISS) – and the miners are obviously not. humans but rather bacteria.
The 18 prototypes for the so-called biomineration took to space in July last year. The RioRock project, by astrobiologists at the University of Edinburgh, in the United Kingdom, aimed to reveal how low gravity affects the natural ability of bacteria to extract useful materials from rocks.
In each biomineral reactor, small pieces of basalt rock were placed immersed in solutions containing cultures of the bacteria Sphingomonas desiccabilis, Bacillus subtilis and Cupriavidus metallidurans (in addition to a solution without bacteria for control). For three weeks, scientists observed whether the bacteria would behave as they did on Earth, but under simulated gravities of the Moon and Mars.
When they reproduce, the bacteria create biofilms, communities of cells adhered to a surface and with each other and protected by a slime. When it forms, it is so cohesive and adhered to the surface where it has reproduced that it is almost impossible to stop its expansion. ]
It was already known that low or absent gravity affects the adhesion of bacteria to surfaces (if they cannot adhere to the rock and cover it, they cannot digest it). With the information obtained, it will be possible to control the process on Earth.
Desolate worlds fertile
The experiment revealed that bacteria can increase the extraction of rare earth metals (by the technology industry) from basalt by up to 400%.
These bacteria may also be the key to transforming the surfaces of desolate worlds into fertile land. According to astrophysicist Charles Cockell, “robotic mines in the Oceanus Procellarum region of the Moon, which has rare earth metal rocks, would be a human scientific and economic advance beyond Earth.”
The next experiment on the ISS will be BioAsteroid; similar to BioRock, it will use as a base not basalt, but material collected from asteroids.