Only traces of useful materials were found. The surface of the Moon turned out to be barren and unattractive for commercial development. Asteroids , however, are another matter. Nearly all the raw materials needed to build a self-sufficient space colony are available on the most common type of asteroid. NASA plans to land a small robotic spacecraft on an asteroid within a few years, just one example of the belief that asteroids are both accessible and worth exploring.
Most asteroids are made from the raw ingredients of the solar system , researchers believe.
Nearly 5 billion years ago, under the tug of gravity, debris from supernovas gathered into a spinning disk. Most of this material fell into the center of the disk and formed our Sun . Further out the material formed many planets. As these planets circled the Sun they collided with each other and grew larger, until just nine planets were left. The debris from these collisions, together with other leftover rubble, was either swallowed up in further collisions or was mostly herded into planet-free zones like the asteroid belt between Mars and Jupiter .