Astronauts could one day end up eating asteroids

Future astronauts could eat a nutritionally perfect diet made from bacteria reared on ground-up asteroids, to produce a kind of milkshake or yogurt, according to New Scientist, Azernews reports.

While astronauts on the International Space Station have experimented with growing salad leaves, the vast majority of food consumed in space is transported from Earth. This would become impossible for more distant, longer-lasting space missions, so Joshua Pearce at Western University in Ontario, Canada, and his colleagues decided to investigate using bacteria to convert carbon-containing compounds from asteroids into edible food.

They have yet to carry out this process using real asteroids, but Pearce and his team have performed similar experiments using bacteria to break down plastic from leftover army ration packets. To do this, they heated the plastic in the absence of oxygen, a process called pyrolysis, and then fed this to a mixture of bacteria that eat carbon.

“When you look at the pyrolysis breakdown products that we know that bacteria can eat, and then what’s in asteroids, it matches up pretty reasonably, actually,” says Pearce. “So I think this can actually work.”

The collective bacteria end up looking “something like a caramel milkshake”, says Pearce, and the team has also experimented with drying out this substance to produce something like yogurt or even a powder.