Meet Amun 3554... Little more than a mile wide, it's one of the smallest M-class (metal-bearing) asteroids yet discovered... So, the total payout from one unassuming asteroid? $20,000,000,000,000. That’s what got Planetary Resources co-founder Peter Diamandis so excited. “There are $20 trillion checks up there waiting to be cashed,” he enthused at a space development conference in 2006.