Every once in a while, mysterious red rain sporadically falls on the southern Indian state of Kerala and Sri Lanka.
Now what is behind this strange phenomenon, staining clothes of baffled residents with blood-like water?
The strange red colored rain phenomenon
Red rains have first been reported on July 25, 2001 in the districts of Kottayam and Idukki, Kerala, India. The colored rain phenomenon was wideley reported over the following ten days and started happening in late September 2001. In the same area, residents also reported yellow, green, and black rain.
The colored rain appears to be a very local and short phenomenon, falling over small areas, measuring no more than a few square kilometres in size and lasting less than 20 minutes.
According to residents, the first red rain was preceded by a loud boom and a bright flash of light, and was followed by the disappearance and sudden formation of wells around the same time in the area.
Initially, scientists suspected that fallout from a hypothetical meteor burst colored the rains. However, an official study found that the rains had been colored by airborne spores from a locally prolific terrestrial algae of the genus Trentepohlia. However, the scientific reasearch found no definite mechanism for the extraordinary dispersal of the spores, nor for the uptake of the suspect spores into clouds.
Here a list of possible causes for those red rains:
- Dust from the deserts of Arabia: LIDAR observations had detected a cloud of dust in the atmosphere near Kerala in the days preceding the outbreak of the red rain. But that hypothesis fails to explain certain aspects of the red rain, such as its sudden onset, its gradual decline over two months, and its very precise localization to Kerala.
- Mammalian blood from a large flock of bats killed at high altitude: An absence of bat wings or other remains found raining from the sky, along with no known natural process would separate the red blood cells from white cells, platelets and other blood components, has led scientists to discount that possibility.
- Extraterrestrial origin: Having collected samples of the rainwater at many locations, two scientists claimed that the colored particles were actually extraterrestrial cells. An isotopic investigation however corroborated the terrestrial origins of the cells found in the red rain.
- Cometary origin: A few hours before the first occurrence of the red rain, residents of Changanasserry in Kottayam district reported a sonic boom, accompanied by a flash of light. Louis and Kumar suggest that the disintegration of a small comet entering the Earth’s atmosphere caused that, the comet containing large quantities of the red particles. This would then become the first evidence speaking for Panspermia, which sustains that life on Earth was carried here from elsewhere in the universe.
Not the only red rains around the world
According to witnesses, red rain fell on August 21, 2007 in the northern part of Kozhikode district. Again, due to algae.
There are also many rivers that turn blood red due to pollution and red tides across the world.
As far as we know, the last red rain event and actually the first time for Sri Lanka was reported in Sewanagala, Monaragala and Manampitiya on November 13, 14 and 15, 2012. Algae again.