Arizona. Eugene Shoemaker (the man behind the comet of the same name, and also an instructor for the Apollo astronauts), armed with a hammer, explores the rim of Meteor Crater, along with Edward Chao. They find extremely rare minerals such as coesite and stishovite, which form only under enormous pressure and temperatures, far beyond those of even the most terrifying volcanoes. The same types of minerals are also found in underground explosions carried out nearby, just north of Las Vegas.
