  A red rain phenomenon occurred in Kerala, India starting from 25th July 2001,
in which the rainwater appeared coloured in various localized places that are
spread over a few hundred kilometers in Kerala. Maximum cases were reported
during the first 10 days and isolated cases were found to occur for about 2
months. The striking red colouration of the rainwater was found to be due to
the suspension of microscopic red particles having the appearance of biological
cells. These particles have no similarity with usual desert dust. An estimated
minimum quantity of 50,000 kg of red particles has fallen from the sky through
red rain. An analysis of this strange phenomenon further shows that the
conventional atmospheric transport processes like dust storms etc. cannot
explain this phenomenon. The electron microscopic study of the red particles
shows fine cell structure indicating their biological cell like nature. EDAX
analysis shows that the major elements present in these cell like particles are
carbon and oxygen. Strangely, a test for DNA using Ethidium Bromide dye
fluorescence technique indicates absence of DNA in these cells. In the context
of a suspected link between a meteor airburst event and the red rain, the
possibility for the extraterrestrial origin of these particles from cometary
fragments is discussed.
