Get the Popular Science daily newsletter💡 Breakthroughs, discoveries, and DIY tips sent every weekday. What astronomers initially suspected to be a new exoplanet is actually a never-before-seen, head-on cosmic crash. As detailed in a study published today in the journal Science, researchers describe the aftermath of two separate collisions between two small, rocky cosmic objects called planetesimals. However, their findings were only made possible by some eagle eye imaging courtesy of the Hubble Space Telescope. This celestial saga began almost 20 years ago. In 2008, astronomers detected an unexplained bright object located 25 light-years from Earth in the Piscis Austrinus constellation. Experts designated  it as Fomalhaut b, but weren’t quite sure what “it” actually was. Initial analysis suggested that it could be a new exoplanet even larger than our own sun. At the same time, its surrounding, roiling cloud of debris hinted Fomalhaut b was an expanding dust formation. Fomalhaut cs2 collision illustration “The system has one of the largest dust belts that we know of. That makes it an easy target to study,” explained …