How Much Are Asteroids Really Worth?
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 (PGMs), which are known for their extraordinarily high cost, relatively low supply, and high usefulness in a variety of modern-day technology. That includes catalytic converters, which is why they are commonly the target of thieves.
The other category would be metals used for in-space construction, such as iron, aluminum, and magnesium. While these might not be economically viable to send back to Earth because of their relatively low prices on our home planet, they are useful up in space for constructing large structures, such as space stations or solar power arrays. However, given the chicken-and-egg problem of not having any demand for these space-sourced metals because they are so expensive, it is hard to quantify how much they are worth. Its competition (i.e. launching the material from Earth), is priceable though, and at $10,000 / kg, plus $100 / kg for a common material such as iron.
