THIRUVANANTHAPURAM, India: The red rain that lashed parts of Kerala last month is eluding explanations as the days go by.

The Centre for Earth Science Studies (CESS) here on Saturday retracted its hypothesis that a streaking meteor triggered the rain.

Everybody had taken that explanation with a pinch of salt because other researchers had spoken of biological contents in the water samples. Yet, the retraction has raised eyebrows about a premier research body’s prudence in making a hurried announcement.

CESS has not only retracted, but tagged a confession: ‘‘This leaves several questions unanswered.’’ The CESS press release was triggered by the chemical analysis of the water samples that showed these were largely biological. Biological studies have identified organic material such as fungal spores in them.

CESS director M. Baba said: ‘‘The exact species is yet to be identified. But how such a large quantity of spores could appear over a small region is as yet unknown.’’

On July 25, Changanacherry town had received the coloured showers overnight that continued into the morning and on till sunset. Some residents collected samples of the rain. They said the shower was accompanied by thunder and lightning.

CESS then collected the samples and tested them. The water was found to be neutral and contained some amount of dissolved salts.

The filtered precipitate was fine and powdery, and this, said Baba, was chemically and biologically analysed.

The chemical analysis showed various elements — including carbon, silicon, calcium, magnesium, aluminum, iron, sodium and potassium. It contained significant traces (in parts per million) of phosphorus, titanium, chromium, manganese, copper and nickel.

The biological study — partly conducted at CESS and at the Tropical Botanic Garden and Research Institute (TBGRI), Pacha Palode — revealed a red coloured cell structure.

This has been tentatively identified as spores of some fungus species and are now being cultured by the TBGRI. ‘‘The red colour of the rain appears to be mainly because of the spores,’’ Baba said.

These findings, say CESS, raise doubts on whether the explosive sound reported by residents and the red rain were independent events. There are other posers too which remain unanswered:

What produced the huge quantity of spores ? Is the source local or distant?

How were the spores injected into the clouds?

If the source is not local, how was the mass transported without getting distributed over a large area?

By way of an answer, CESS has only this to say : ‘‘While the cause of the colour in the rainfall has been identified, finding the answers to these questions is a challenge.’’

• Story originally published by:
The India Express | Kamal Gopinath Nair - Aug 6 2001