Good news! We're on the precipice of the next great gold rush... but it won't be in the hills of California. Or anywhere on this planet. It'll be in outer space, as there are untapped rare materials in asteroids that could be used for future technologies. That's right: there's gold in them thar skies! Theoretical physicist and one of our favorite Big Thinkers, Dr. Michio Kaku, explains to us that while China might have a stranglehold on the rare minerals and metals on our planet, there's no stopping interplanetary mining. We've even got an actual plan with actual economics already in place... we just have to wait until NASA's SLS rocket technology fully develops. Michio Kaku's latest book is the awesome The Future of Humanity: Terraforming Mars, Interstellar Travel, Immortality, and Our Destiny Beyond Earth .