space rock originated from the asteroid belt. Scientists estimate the asteroid's journey across the solar system took nearly 23 million years. In the early hours of June 2, 2018, astronomers at the University of Arizona saw a faint dot of light moving across the sky. It was an asteroid, which loomed larger and larger as it approached Earth. A few hours later, the 6-foot-wide space rock - named 2018 LA - caught fire as it roared through the atmosphere at a blistering 38,000 miles per hour. It broke into tiny fragments that rained down across Botswana. A group of researchers raced to the end of that fireball's path to hunt for the rare fragments, since they held clues about the asteroid's origins.