Professor Chandra Wickramasinghe, the director of the Buckingham Centre for Astrobiology at the University of Buckingham in the UK, and Dr Martin Ferus, from the Department of Spectroscopy, at the Czech Academy of Sciences have different views on this subject, and discuss them in this program.
Dr Ferus starts the programme by explaining that about 36,000 tons of interplanetary dust enters our atmosphere every year. "This seems like a lot," he says, "but over the past 4 billion years the total amount of dust hitting the earth represents only about 3% of the total weight of our atmosphere. Most of the dust particles do not contain atmospheric particles but silicate, and their amount is absolutely negligible in comparison with the total mass of the earth's surface."
It is not the quantity that is important, however. "You don't need more than one or two hundred living cells to start off life on any planet. So I think the quantity is not the relevant issue. It's the mechanism by which life can be transported. We know that life exists on the earth of course, we know that some of these life forms could reach high into the atmosphere, even the stratosphere and very recently, Russian cosmonauts have been discovering microscopic life forms on the outside of the International Space Station which is orbiting at 400 kilometers above the earth's surface. So you can have life existing beyond the atmosphere of the earth, but the real question is: how did life begin on earth? All of the experiments that have been done so far have been based on the presumption that life started on earth….There have been people who have been working on this for a lifetime, and there has been absolutely no success in turning non-life to life on the very small scale of our planet….The possibility that life is transported to us from the very much bigger system which is the cosmos is something that many of us have discussed and talked about for quite a long time."
Dr Ferus, however, doubts that life can in fact travel across space, and he also considers that the speed of which life can travel is too slow. The possibility of living organisms on interstellar dust surviving the very long periods of time in space is unlikely he says. Professor Wickramasinghe argues however that life forms can exist within larger objects, such as meteorites and comets, almost indefinitely. "In amber which has been discovered from prehistoric times, micro-organisms have survived for something like two or three or four million years. The importance of that is that the earth's environment is not entirely radiation free; background radiation is hitting these organisms and they are surviving for millions of years. And by analogy, we calculate that organisms, even unprotected, can survive the long passages of time needed to travelling from one planetary system, to another. The survival of just a handful of micro-organisms is enough to fertilize a planet." Dr Ferus argues that we need to research what happens to organisms when exposed to solar radiation to see if particles can survive this kind of radiation."
Dr Ferus proposes that life evolved on earth, and that once the process started it developed very quickly. Professor Wickramasinghe, however, argues that there is no evidence to support that hypothesis, and that such theories are "speculation, almost religion." Talking about religion, host John Harrison suggests that the 'panspermia idea' threatens the whole creationist idea. Professor Wickramasinghe replies that when it comes to life and the origins of life, there is a mystery. "Whether life came from a chemical process or whether it came from outside the universe, there is still is an unresolved puzzle as to where the information part of life has come from, and that is unanswered, so this is the link to religion." Dr Ferus insists however, that the velocity of interstellar dust is too low, and that there is no proof that microcosms can survive for millions of years in interstellar conditions." Professor Wickramasinghe insists that if we know that life exists on earth, then we have to accept that life exists elsewhere in the universe. The argument that life consists of the same building blocks everywhere, however was used against Professor Wickramasinghe, as if life exists everywhere, why could it not have developed on earth? Professor Wickramasinghe answers that the evidence that we have now is very strongly pointing in the direction that life did not start here on the earth, but came from a very much bigger system. Life is a truly cosmic phenomenon."
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