In 2001, red rain fell on parts of Kerala, India, on and off for about two months. Scientists traced the color to algae spores, but one physicist argued the cells came from space.
On 25 July 2001, brief, sharply localized showers began turning collected rainwater red across parts of Kerala. The phenomenon continued intermittently for about two months. Government scientists identified spores of the lichen-forming alga Trentepohlia, while physicist Godfrey Louis later argued that the cells had arrived in a disintegrating comet.
