There Are Only 10 Asteroids Worth Mining

The burgeoning space mining industry might be short lived if Harvard astrophysicist Dr. Martin Elvis' calculations are correct. Elvis has just released a study estimating that just 10 near-Earth asteroids could be mined cost effectively, the BBC reports. Elvis assumed that miners would want to grab M-type rocks, the iron-nickel ones most likely to contain platinum-group metals, and that they wouldn't be interested in asteroids smaller than 100 meters.

Elvis also pointed out that just identifying those asteroids would be valuable—and difficult. In a follow-up study, he calculated that to find just one ore-bearing asteroid, you'd need to probe two dozen, Mining.com reports. But Planetary Resources, the most prominent space mining startup, isn't daunted, saying Elvis made some false assumptions; they'll be going after C-class asteroids, for example. "I think the study is probably off by a factor of 100, conservatively, and I think it's off by a factor of 1,000 optimistically," one co-founder said. (More Planetary Resources stories.)