Red Rain in Kerala - Criticism

Criticism

Louis and Kumar made their first publication of their finding on a web site in 2003, and have presented papers at conferences and in astrophysics magazines a number of times since. The controversial conclusion of Louis et al. is the only hypothesis suggesting that these organisms are of extraterrestrial origin. And every time, they've been popular with the mass media, with major news agencies like CNN repeating their sensational panspermia story without critique, although almost nobody else in the scientific community accepts Louis and Kumar's space spore explanation.

Hypothesis' authors – G. Louis and Kumar – admitted no explanation on how debris from a meteor could have continued to fall on the same area over a period of two months, despite the changes in climatic conditions and wind pattern spanning over two months. Samples of the red particles were also sent for analysis to his collaborators Milton Wainwright at Sheffield University and Chandra Wickramasinghe at Cardiff University. Louis then incorrectly reported in 29 August 2010 in the non-peer reviewed online physics archive "arxiv.org" that they were able to have these cells "reproduce" when incubated at high pressure saturated steam at 121°C (autoclaved) for up to two hours. Their conclusion is that these cells reproduced, without DNA, at temperatures higher than any known life form on earth is able to. They claimed that the cells, however, were unable to reproduce at temperatures that earthly cells do.

Regarding the "absence" of DNA, Louis admits he has no training in biology, and has not reported the use of any standard microbiology growth medium to culture and induce germination and growth of the spores, basing his claim of "biological growth" on light absorption measurements following aggregation by supercritical fluids, an inert physical observation. Both his collaborators, Wickramasinghe and Milton Wainwright independently extracted and confirmed the presence of DNA from the spores. The absence of DNA was key to Louis and Kumar's hypothesis that the cells were of extraterrestrial origins, and Louis apparently has ignored their findings too, and to date he still claims that the spores contain no DNA.

Louis' only reported attempt to stain the spore's DNA was by the use of malachite green, which is generally used to stain bacterial endospores, not algal spores, whose primary function of their cell wall and their impermeability is to ensure its own survival through periods of environmental stress. They are therefore resistant to ultraviolet and gamma radiation, desiccation, lysozyme, temperature, starvation and chemical disinfectants. Visualising algal spore DNA under a light microscope can be difficult due to the impermeability of the highly resistant spore wall to dyes and stains used in normal staining procedures. In order to stain the spores' DNA, which is tightly packed, encapsulated and desiccated, spores must first be cultured in suitable growth medium and temperature in order to first induce germination, then cell growth followed by reproduction.

Other researchers have noted recurring instances of red rainfalls in 1818, 1846, 1872, 1880, 1896, and 1950, including one described by Charles Darwin, and several times since then. Most recently, colored rainfall occurred over Kerala during the summers of 2001, 2006, 2007, 2008, and 2012; since 2001, the botanists have found the same Trentepohlia spores every time. This supports the notion that the lichen spores are a seasonal local environmental feature, rather than Kerala being some kind of a magnet for alien-microbe infested meteors.