From July 25 to September 23, 2001, red rain sporadically fell on the southern Indian state of Kerala. Heavy downpours occurred in which the rain was colored red, staining clothes pink. Yellow, green, and black rain was also reported. Colored rain had been reported in Kerala in as early as 1896 and several times since then. Following a light-microscopy examination in 2001, it was initially thought that the rains were coloured by fallout from a hypothetical meteor burst, but a study commissioned by the Government of India concluded that the rains had been coloured by airborne spores from a locally prolific terrestrial green alga from the genus Trentepohlia.
Red rain
