From July 25 through September 23, 2001, the state of Kerala in India experienced several instances of bizarre red rain. While several theories have been suggested to explain the phenomenon, scientists do not agree on an explanation despite years of testing and research. Initially, the particles were blamed on an exploding meteor, which would explain the loud boom heard by residents. Researchers later changed the theory when electron microscopy determined the particulates resembled spores, possibly produced by algae and/or fungi. A later theory suggested the strange event was due to dust from sandstorms. Another study cast doubt on the connection between the loud (possibly sonic) boom reported to have preceded the rainstorm while others determined the red particles as “extraterrestrial in origin.” To this day, the rainstorms have not been definitively and satisfactorily explained.