In August 1865, a 10-pound rock fell from space to Earth, landing with a bang in the remote village of Sherghati, India. After being recovered by witnesses to the event, the stone passed into the possession of a local British magistrate who endeavored to identify the source of the strange object. After more than a century of studying the meteorite fragments—so-called shergottites—researchers in the 1980s finally determined its alien origins: our neighboring planet, Mars.