An international team of scientists found a 900-kilometer-long "strewn field" of tektites, rocks that form when terrestrial material is rapidly heated by energetic impacts. While this research proves that an impact did occur in South America’s distant past, geologists are still looking for the impact crater itself. In its 4.6-billion-year history, Earth has had some truly catastrophic run-ins with ancient celestial bodies. And now, an international team of scientists has found evidence of another ancient impact, thanks to a strewn field of tektite. The largest tektite strewn field, called the Australasian, covers roughly 10 percent of the Earth’s surface, and others have been spotted in central Europe, the Ivory Coast, North America, and Belize.