THE NEW SPACE RACE: One astronomical object could be the best resource for future space colonies. “The metal-rich asteroid 16 Psyche is a good possibility. Mining the interior of its estimated trillions of dollars worth of rare earth metals would also provide a radiation-shielded habitat, as long as rapidly spinning Psyche doesn’t cause it to fly apart. On this point, the concept looks promising. One study of spinning asteroids found that solid ones up to a few hundred yards in diameter should tolerate a spin rate fast enough to sustain artificial gravity up to half a gee or so.”