Popular media love talking about asteroid mining using big numbers. Many articles talk about a mission to Psyche, the largest metallic asteroid in the asteroid belt, as visiting a body worth $10000000000000000000, assumedly because their authors like hitting the “0” key on their keyboards a lot. But how realistic is that valuation? And what does it actually mean? A paper funded by Astroforge, an asteroid mining start-up based in Huntington Beach, and written by a professor at the Colorado School of Mine’s Space Resources Program takes a good hard look at what metals are available on asteroids and whether they’d genuinely be worth as much as the simple calculations say that would be.
The paper divides metals on asteroids into two distinct types—those that would be worth returning to Earth and those that wouldn’t. Really, the only metals judged to be worthy of returning to Earth are the platinum-group metals …