From the Stone Age to the Space Age, our world has been built from rocks. Visit the Johnson Space Center in Houston to examine America’s horde of moon rocks to determine how the planets were formed, and how old the solar system is. See how marble and granite are extracted, cut and polished. Do some blasting at a gravel pit, watch ore turn into steel and finally, learn how the Geysers in Northern California harness heat from rocks to create energy for 85,000 homes.