Using microorganisms to mine meteorites could be an effective way to extract precious metals in space, scientists say. This is the subject of an experiment aboard the International Space Station that examines how such mining in low-gravity environments could support space exploration.
Researchers from Cornell University and the University of Edinburgh have been working on a study based around the results of the experiment, which was carried out by NASA astronaut Michael Scott Hopkins. “This is probably the first experiment of its kind on the International Space Station on meteorite,” Rosa Santomartino, Cornell professor and first author for the study, said in a statement to Cornell Chronicle.
The experiment used two different microorganisms for the meteorite extraction — a bacterium, called Sphingomonas desiccabilis, and the fungus Penicillium simplicissimum.
“These are two completely different species, and they will extract different things,” Santomarinto said. “We wanted to understand how and what, but keep the results relevant for a broader perspective, because not much is known about the mechanisms that influence microbial behavior in space.”
The microbes “mined” the specimens by producing carboxylic acids, which attached themselves to minerals in the meteorites. The acids help to release the minerals into a liquid solution.
The researchers specifically wanted to see how the extraction method worked in space compared to how it works on Earth. While the method worked similarly in both environments, there were some interesting differences, Cornell researcher Alessandro Stirpe said in the same statement.
It turns out that space changed the fungus’ microbial metabolism, which allowed it to increase molecule production, including carboxylic acids. This enhanced the release of palladium, as well as platinum and other elements,” the statement says.
The researchers warned there are many variables, so their work may not necessarily lead to a tidy conclusion. “Another complex but very interesting result, I think, is the fact that the extraction rate changes a lot depending on the metal that you are considering, and also depending on the microbe and the gravity condition,” Santomarinto said.
Resource production in space has become more important as space companies and agencies are looking into how to reduce the cost of long-term space travel. One way to cut the cost is by mining materials in space, rather than shipping them from Earth.
Some of the minerals that can be mined in space are also very valuable. Palladium is a precious metal with a variety of specialized uses in technology, and even very small amounts can fetch thousands of dollars.
For instance, Astroforge is one of the companies that’s been working on asteroid mining. But rather than relying on microorganisms, Astroforge has been working on a process that involves lasers and magnets to extract minerals from asteroids.
