Now for a few phenomena that are even weirder. In July 2001, a strange red rain began to fall in Kerala, India. Scientists have proposed several different theories to explain the rust-colored rain; some speculated that the rain might have contained desert dust, others suggested that it might have contained fungal spores, and one pair of researchers even published a paper raising the possibility that the rain contained small particles from a meteor.

The Indian government commissioned a study [pdf] to get to the bottom of the matter, which concluded that spores from algae were indeed to blame. But the scientists had no answer to how enough spores got into the atmosphere to color the rain.