You spend time in mining materials and minerals, all of these you will eventually master after visiting several planets. (bundle-in-a-box.com)
NASA's Kepler mission has found several planets within this zone, and researchers continue to scrutinize the Kepler data for candidates as small as Earth. (sciencedaily.com)
Our solar system may have started out with several planets packed closer to the sun than Mercury, much like the planets we see around other stars (newscientist.com)