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'Our destiny is in the stars'
Lankan astronomer Prof. Chandra Wickramasinghe who advocates the theory that Earth and other planets in the universe may have been established by a collection of bacteria at the edge of our own atmosphere, talks about his research and the Rosetta Lander project

By Aaysha Cader
On February 26, 2004, the European Space Agency probe Rosetta lifted off from the Space Centre in Kourou, French Guiana and began its 10-year journey to meet the comet 67/P Churyumov-Gerasimenko ('Chury'). Completing a 675-kilometre cruise, Rosetta, launched aboard an Ariane 5, will rendezvous with the comet in August 2014. The Rosetta Lander will land on the surface of the comet and carry out extensive investigations on the comet and its environment-the first time ever a spacecraft will perform a soft landing on a comet's nucleus.

The £ 600-million mission is of vital importance to Sri Lankan-born astronomer Prof. Chandra Wickramasinghe, as the scientific data revealed by the probe will shed new light on the evolution of comets and their origin as part of the originating material of the solar system. Prof. Wickramasinghe, who was in the island last week to deliver the University of Colombo's Sujatha Jayawardena memorial oration, is Director of the Cardiff Centre for Astrobiology and one of the leading exponents of a theory known as Panspermia, which advocates that earth and other planets in the universe may have been established by a collection of bacteria at the edge of our own atmosphere.

"Rosetta had been doomed for some time," said Prof. Wickramasinghe, of the mission that was due to have been launched last year, but was eventually postponed following an explosion of a rocket at the probe's launch site. Its original target, Comet Wirtanen had to be replaced as well. "They lost the comet as it travelled," he explains.

Of particular interest to him is the comparison of dust material found on the coma of the comet, with micro material from comets that are currently raining down on earth. Prof. Wickramasinghe, however believes that the answers to the questions of our origin will be resolved long before 2014, but adds that the significance of these developments will be the noticeable change of attitude towards accepting the thesis of cosmic life.

Cometary material
Prof. Wickramasinghe argues that if comets brought the first life onto Earth, and possibly onto other planets as well, then the process could not have stopped at some distant time in the past. With some 100 tonnes of cometary material reaching the earth on a daily basis, he together with the Indian Space Research Organisation (ISRO) conducted research to test for evidence of living particles and microbes coming in with this influx of debris.

Samples of cometary dust were collected via a cryogenic stratospheric sampler, which was launched from the TATA Institute Balloon Launching Facility on January 20, 2001. Air was collected aseptically from a height of 41 km into the stratosphere, well above the local tropopause (16km in tropics), above which no aerosols from lower down would normally be transported. "There's no way that what we brought down from the stratosphere could have been lifted up there from Earth," explains the Professor, a co-principal investigator of the project, affirming that the dust collected had to come from outside of Earth, "the only doubt is that it might have been carried up there by a balloon."

Back in the laboratories, the air was examined for signs of life. With similar structures of rods and cocci (bacteria types) showing from the electron microscope image, as well as of the special microscopic views following experiments of cyanine (which is only taken up by membranes of living cells) on the isolate, and after the detection of DNA in these clumps, the researchers came to the conclusion that living cells did indeed exist, well above reach from Earth.

Prof. Wickramasinghe provisionally estimates the daily input of such biological material to be between one third to one tonne over the entire planet. "We have probably had it from the dawn of Earth," he says, adding that it is bound to affect us, and the consequences cannot be ignored. "These microbes carried genetic material into the Earth, and we are simply localising it," he explains. Another balloon flight of this kind is planned for next year, and he believes this would provide unequivocal proof of the much-talked-of theory of Panspermia.

Life began from space
Prof. Wickramasinghe has always been a firm believer that we came, and life itself began, from space, in that all our genetic information came in neatly packaged from elsewhere in the universe. Detailing the ancient theory of spontaneous generation, which was well-supported by Aristotle, he explains how Louis Pasteur's experiments refuted the claim, and gave vent to the logical deduction that life is always derived from life that existed before. They were followed by cosmological interpretations to the origin of life by European scientists John Tyndall, Lord Kelvin and most concisely, Hermon von Helmholtz.

But it was Swedish chemist Arrhenius who made it most succinct, even proposing an explicit method in which bacterial spores could be transferred from one star system to another. His ideas became popular as Panspermia - coined from Greek roots- pans (meaning all) and spermia (meaning seed), to convey the connotation 'all-seeding' or 'life everywhere'.

Later, Panspermia was challenged by the notion that cosmic radiation was a hazard to travelling bacteria. It turned out to be a total red herring, says Prof. Wickramasinghe, explaining that carbonaceous coatings only a micron thick would offer almost complete shielding from UV radiation, and such coatings will inevitably occur under the conditions that prevail in space.

In any case, most recent discoveries have confirmed the incredible survival attributes of bacteria - a 30 million- year- old bee, fossilised in amber, has been shown to contain viable micro organisms in its guts; And a quarter of a billion years -old dormant bacterium in a salt crystal has been shown to have survived hundred megarads of ionising radiation.

Primordial soup
As for the widely embraced theory of the building blocks of life originating from a 'primordial soup', Prof. Wickramasinghe says that it is superbly impossible, as the origin of life is not just the formation of chemical building blocks, but also the emergence of highly specific arrangements of these molecules into biological structures such as enzymes.

The 'primordial soup' theory states that building blocks of proteins (amino acids), DNA (nucleotide bases) etc. were produced at the beginning of time through electric discharges and UV light, from partially reduced gases in the Earth's atmosphere.

But with decades of research, Prof. Wickramasinghe has developed the viewpoint that the Earth was simply a 'receiving station', a building site for a magnificent edifice of cosmic life, and that nothing of great biological significance occurred on this planet.

He says that whatever that came in units (i.e.clumps of bacteria) were naturally selected and best suited to the local environment, according to the criterion of 'survival of the fittest'. "Thus the Darwinian principle is more a case of fine-tuning the idea," says he.

He accepts, however, that any theory is accompanied by controversy, especially from religious quarters. "If you try to propose any mechanism that doesn't involve the creator, it leads to controversy," he says, adding that the nature of life is a revealed truth.

Recent discovery
Of newer developments in the field of astronomy, Prof. Wickramasinghe spoke of the most recent discovery of a new 'planet' Sedna, which lives in the Kuiper belt, a region of space beyond Pluto filled with at least 70,000 icy rocks. He says that there is still argument as to whether it is a planet or a comet of the Kuiper belt.

He disclosed that it may likely be a planet due to its radius, but says (citing Uranus and Neptune which came to be following a collision of comets) that the new 'planet' might have cometary possibilities as well.

An award-winning poet, Prof. Wickramasinghe also believes that the perceived differences between the humanities and the sciences have no real significance at the deepest level.

He said at the oration that, "The poet and scientist explore the self- same universe, but using different methods and different tools." His subjects of poetry are varied - influenced by the Haiku style of poetry, Prof. Wickramasinghe writes of the universe, life, love,.. everything. "It may not be very profound in terms of depth," he says, "Just little glimpses of the universe."

He regrets that with industrialization, man decided that he wanted autonomy, adding that it led to a 'disconnection' between ourselves and the cosmos. "Our ancestors put their Gods and Goddesses in the sky," he says, and to them, thousands of years ago the spectacle of the night sky would have been pregnant with meaning. "With industrialisation, we sought complete control of our destiny," he says, adding "That's an illusion - I think our destiny is in the stars."

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