In July 2001, red-colored rain began falling in the Indian state of Kerala. For the next two months, it returned intermittently. A number of theories explaining the origins of the coloration were proposed, including that it was contamination from a dust cloud, debris from a volcanic eruption, and even extraterrestrial cells. The Indian government initially speculated that the red rain was caused by an exploding meteor but later issued an official report asserting that it had been caused by what? Discuss
Source: The Free Dictionary