Asteroids contain gold and other valuable and rare metals that entrepreneurs and scientists on Earth are eying greedily. Space mining could potentially be one of the most lucrative industries in history – if not the most lucrative. There are huge obstacles to space mining ever becoming a practical reality.
But the rapid scientific advances we’re seeing in the 21st Century mean that many believe it will one day be possible to mine asteroids. And microbes are considered to be the key to unlocking the riches of space mining.
Experiments being conducted on the International Space Station have explored a process call “biomining”, which has shown the potential to work in the microgravity conditions space miners will have to contend with. Biomining, which is already used here on Earth in certain circumstances, involves microbes being released into rock. The microbes digest the rock, leaving behind the metals.
As well as being brought back to Earth, metals mined in space are considered key to the future possibility of building human colonies beyond our own planet. Charles Cockell of the University of Edinburgh comments:
“If we are going to establish permanent settlements on other planets, we need elements. We need iron for rovers, rare earth elements for electronics.”
Professor Cockell and a number of his colleagues have been trying to answer the question of whether rock-digesting microbes would be able to do a similar job to what they’ve been used for on Earth, in an environment of extremely low gravity. Which is what they would have to contend with on asteroids, or the moon.
They tested how biomining microbes would be expected to perform in such conditions by building miniature “biomining reactors”. The reactors contain lumps of basalt, a kind of rock formed from the rapid cooling of lava rich in magnesium and iron exposed at or very near the surface of a terrestrial planet or a moon. The basalt is left in a ‘soup’ of rock-eating microbes held within the reactor. The team then sent 18 of these reactors 250 miles up to the International Space Station to see how extremely low gravity would affect the usual process.
The research, recently published in the scientific journal Nature Communications, showed that the microbes were unaffected by the lower gravity. They still digested the rock and left behind sugars, which bonded with the rare elements left behind. As would have been expected if the experiment had been conducted back on Earth.
The results of the research offer home that the rare earth elements used in sophisticated electronics can be mined directly in space. With every kilogram carried into space coming at a cost of tens of thousands of pounds, anything needed that can be mined on the moon or beyond has the potential to make missions far more economically viable.
For now, the goal is to contribute towards the financial viability of scientific space missions, rather than commercial space mining. But there is a lot of commercial interest in mining asteroids, which is currently economically unviable. The small European country of Luxembourg has a state programming looking at space mining as a way to potentially generate income.
Professor Cockell comments:
“Often when one talks about space mining, people have the idea it is pie in the sky, that it is about going out and collecting elements to bring back to Earth. This is thinking instead about ways to create self-sustaining settlements beyond Earth.”
One element to biomining in space that has to be very carefully controlled is the microbes themselves. On Earth, this kind of mining is the environmentally friendly option. Introducing life forms into the life-vacuum of space is something that has to be handled with extreme care and why space probes are sterilised. Nobody knows what might result from rogue colonies of microbes left to their own devices in pristine spacescapes.