FYI: How did we get here?
FYI: How did we get here?
Doctor Godfrey Louis, a physicist at Mahatma Gandhi University in India, thinks he may have the answer. In April last year, he published a paper in the Astrophysics and Space Science journal about a downpour of 'blood-coloured' rain that had drenched his state, Kerala.
The mysterious rain, which fell during the summer of 2001, contained what may have been a strange life form of extraterrestrial origin, according to Louis, who conducted an extensive analysis of rain samples. Louis says the samples contained bizarre, thick-walled, red-tinted cell-like structures. The particles appeared to lack DNA yet reproduced plentifully, even in water heated to 300 degrees Celsius, Louis wrote. He theorised the particles came from a meteor or comet fragment that exploded above Kerala; a loud explosion was heard just before the red rain fell.
While at first glance Louis' theory appears far-fetched, the idea that 'seeds' of life exist elsewhere in the universe - and that life on Earth may have sprouted from such seeds - is not new. It even has a name: panspermia. The first known mention of the idea was made by the 5th century BC Greek philosopher Anaxagoras, but the theory remained dormant until the late 19th century, when it was revived by a number of scientists, German physicist Hermann von Helmholtz and Swedish chemist Svante Arrhenius among them.
British astronomer Sir Fred Hoyle (1915-2001) and Sri Lankan-born Professor Chandra Wickramasinghe, of Cardiff University, have been important proponents of the hypothesis, contending that life forms continue to enter Earth's atmosphere and may be responsible for epidemic outbreaks and new diseases.
In 2001, a triumphant Wickramasinghe told a scientific conference in California he had made the first positive identification of extraterrestrial microbial life in samples of air taken kilometres above the tropopause, an invisible barrier in the Earth's atmosphere. Unfortunately, he has not been able to prove the living cells he found 41km above the Earth's surface did not originate on this planet.
Another prominent proponent of panspermia was Nobel-Prize-winning English physicist Francis Crick, who took the idea a step further. Along with chemist Leslie Orgel, Crick proposed the theory of directed panspermia in 1973. This suggests the seeds of life may have been purposely spread by an advanced extraterrestrial civilisation. Crick argued that small grains containing DNA, the building blocks of life, fired randomly in all directions was the best, most cost-effective approach to seeding life on a compatible planet: a strategy our resource-hungry race may have to resort to in the future. Such a strategy might have been pursued by a civilisation facing catastrophic annihilation or hoping to terraform planets for later colonisation, he suggested.
Panspermia could be either interstellar (between star systems) or interplanetary (between planets in the same solar system). Wickramasinghe's euphoria notwithstanding, there is as yet no compelling evidence to support or contradict it, although the majority view holds that panspermia - especially in interstellar form - is unlikely given the rigours of survival and transport in space.
Sci-fi or sci-fact, panspermia remains intriguing for the possibilities at which it hints.
