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Lankan Astronomer Prof. Chandra Wickremasinghe, the man behind some radical theories on life in outer space speaks to The Sunday Times
Life on Mars. For several weeks now, the topic has been titillating the imaginations of an entire world. When several scientists at the American space agency NASA, first announced the discovery of bacteria-like forms inside a lump of Martian rock, a frenzy of media coverage shocked and thrilled millions of people. The news was exciting and scary. Many did not believe it. For others it was an anticlimax - Martians were not the slimy green three-eyed monsters of popular science fiction but in reality, smaller versions of earth dwelling bacteria.
For Sri Lankan born astronomer, Chandra Wickremasinghe the news did not come as a surprise. As the first scientist to write about life in outer space, and as a leading researcher into cosmic sources of life, he was not taken unawares when the announcement of life signs on Mars was made in July. "There is no doubt that there is life on Mars," Prof. Wickremasinghe said. This may have been proved by the NASA tests on the lump of Martian rock, but research done by Prof. Wickremasinghe with another eminent British astronomer Sir Fred Hoyle points out that biological life could exist under the polar ice caps on Mars.
Prof. Wickremasinghe was in Sri Lanka briefly last week en route to England, where he is Professor of Applied Mathematics and Astronomy at the University of Cardiff.
In an interview with The Sunday Times, Prof. Wickremasinghe said that there is no doubt that the images of very primitive single celled life that emerged from electron microscope images of the lump of rock were living cells- once upon a time in Mars. He said that there were signs of cells in the process of division- which is their way of reproduction. Chances that the lump of rock could have been contaminated after it landed on Earth are indeed slim. " The bacterium like cells are in the middle of the rock and not on the surface," he explained.
Earlier research done by Prof. Wickremasinghe and his colleagues pointed to life signs on Mars. "The only disadvantage was that we did not have a lump of Martian rock to prove the theory." Apparently this research pointed out that there are signs of sub- surface water in Mars which could host biological life forms- mostly under the polar ice caps of the red planet.
"These ice caps erupt at times and dust like debris is spewed out. We think that this is a result of bacterial activity, since the ice caps could not simply explode out," Prof. Wickremesinghe said.
Prof. Wickremasinghe and his one-time teacher, Sir Fred Hoyle are regarded by the scientific community at large as those backing rather radical theories about the evolution of life. According to Prof. Wickremasinghe, the universe is teeming with life in the form of frozen single celled bacterium like creatures who are found in comets and asteroids as well as in cosmic dust. These are rained down on planets and stars as a result of various cosmic activity, and when they find conditions favourable, like the presence of water and an atmosphere, as is on Earth and perhaps Mars, life is begun.
This theory goes on to say that one celled bacteria- like creatures can survive tens of millions of years dried and frozen in deep space and come 'alive' again when they meet the correct conditions. This has been proven on Earth where bacteria inside a resin trapped bee, some 25 million years old were revived and they began reproducing in laboratory experiments. "Comets are made of water and biological life in such frozen inert forms," Prof. Wickremasinghe said.
Comets, when they crash into a planet, deposit this water and seed the planet with primitive forms of life. "The oceans and the atmosphere of the earth were created by hurtling comets. The latest geological findings point out that around 3800 million years ago, the Earth was bombarded with comets. As soon as these collisions stopped, life suddenly begins on Earth," Prof. Wickremasinghe said.
The fist- sized rock from Mars, which was buried in Antarctic ice until it was discovered by NASA, was dated back 3600 million years by the scientists. At this time it would have been part of the Martian surface, removed by some impact and sent hurtling to space to end up in the freezing ice of the South Pole, where it lay for some 13,000 years. "It is likely that the two planets (Earth and Mars) were seeded by the same source," he said.
"Or they could have been cross infected- life could have travelled from Mars to Earth or vice versa."
The evolution of life on earth is a very controversially debated subject. It is said that the scientific community is sharply divided as to whether life originated on earth itself or whether it was imported from the deeper reaches of space. Prof. Wickremasinghe strongly advocates the latter argument-that life is not a phenomenon that is unique to the earth. It is in fact, a very common occurrence in the universe. In fact planets like Earth and Mars were seeded from this vast depository of outer space life," he says.
"The standard point of view preferred by Western astronomers is that life evolved in a primordial soup of elements on earth. But there is little fact to substantiate this. Life cannot evolve from non-life. It is much more likely that life is a cosmic phenomenon and has its origins deep in the universe," Prof. Wickremasinghe said.
There are some 100 billion stars-more or less like our sun in the Milky Way, which is only one among billions of other such galaxies in the universe. At least some of these 100 billion stars have to have planetary systems. "In these terms, it would be impractical to think that life is unique to the earth," Prof. Wickremasinghe said. "One could assume that there is not only single celled life in the cosmos, but that there would have taken place evolution process similar to what occurred on Earth."
He said that the long history of science in Europe favoured extremely Earth -centered views of the universe. "Most theories that were essentially Earth centered were later disproved.
Battling these odds, Prof. Wickremasinghe and Sir Fred Hoyle will continue to gather data to prove their theory of life in outer space. Even as he ended our interview, Prof. Wickremasinghe was preparing to fly back to England, having lectured in Singapore on their research findings. "My religious and cultural background has helped greatly in my work. It gave me a mental advantage over my Western colleagues to accept without reserves the theory of life in outer space," Prof. Wickremasinghe concluded.
Prof. Chandra Wickremasinghe believes the answer lies deep in the folds of the universe. Reproduced here are some excerpts of a lecture by the Sri Lankan Astronomer, on his theory of the origins of life, made shortly after the discovery of life signs on Mars.
It is clear that any model of the Universe that one considers must, first and fore most, be consistent with the presence of life within it. And it stands to commonsense that an ultimate origin of life, if indeed there was one, must have involved the combined resources of all the stars in all the galaxies in the entire Universe. It is also amply clear that models of the Universe with an open time scale will be far better placed to explain the origin of life than the rather simplistic big-bang Universes, which are just three times older than the Earth. It is perhaps relevant to our argument that the most recent astronomical data which involves measurement of the so-called Hubble constant, have stirred a veritable hornet's nest amongst cosmologists. There is still a great deal to argue about concerning the precise value of this constant, but serious contradictions are beginning to emerge in regard to the widely accepted standard big bang cosmology. The age of the Universe is turning out to be 10-11 billion years, whereas stars in our own galaxy have ages exceeding 15 billion years - this would be true only if the universe was of a simple big bang type and of course one cannot have objects within the Universe that are older than the Universe itself. A self consistent model of the Universe that has great merit in regard to the ultimate origins of life is one in which there was not a single unique big-bang, but an unending sequence of mini bangs. Thus a chain of inter-connected bits of the Universe would extend over an infinite volume and with an open time scale. The super-astronomical improbabilities for life's origins could then easily be overcome.
As far as life is concerned what is of course utterly obvious is that there is no logical requirement whatsoever for life to have started here on the Earth. A mere glimpse at our Universe would show you that the odds are stacked exceedingly heavily against such an origin.
Add further the fact that living material is made up of very common cosmically-occurring elements such as carbon, nitrogen, oxygen, hydrogen and phosphorus, and that organic molecules of a complexity approaching biochemicals have actually been found outside the Earth in the deepest recesses of interstellar space. Last year radio astronomers discovered vast quantities of the amino acid glycine (a molecule present in proteins) in the vast clouds of interstellar dust near the centre of our galaxy and more recently vineger has also been discovered in this same region.
Also let us recall that the Earth is an open system. It is not sealed away from cosmic contaminants or cosmic molecules. The Earth is continually bombarded by small comets at a steady rate. Data from US spy satellites, that have only recently been declassified, show that small comets measuring 30-50 metres across do indeed collide with the Earth's upper atmosphere and explode at the rate of about 3 or 4 every year. And these are real events that have been recorded over the past 25 years.
The Sun and its planetary system, including the Earth, had its beginnings some four and a half billion years ago in a cloud of cosmic gas and dust We know that new stars are born within such interstellar dust clouds. The precise details of the physical processes involved in the spawning of new stars are not yet understood, but we know that myriads of tiny solid particles of radii about 1/3 of a micrometre, the average size of a bacterium, play a crucial role. They go into regions where stars form and they re emerge from the neighbourhood of newly formed stars in vastly amplified numbers. The millions of clouds of diffuse material that populate the Milky Way are filled with such particles, which show up as a cosmic fog, dense enough in many instances to blot out the light from distant stars.
From a personal standpoint the beginnings of a cosmic theory of life were connected with my attempts to understand the nature of cosmic dust. In the early 1960's Sir Fred Hoyle and I had suggested that the cosmic dust particles might be made up mostly of carbon in the form of graphite. After a while we realised that this simple idea could not be the whole answer. We tested mixtures of graphite with other inorganic substances and when all these inorganic mixtures had proved inadequate we considered in 1974, the possibility of grains comprised of mixtures of complex organic polymers. These organic particles turned out to be much better placed than inorganic dust grains, but real success in obtaining a good match to all the available astronomical observations continued to escape us until we finally homed in on the hypothesis that interstellar gains, or at least a major component of it, may in fact be freeze dried bacteria.
When we first considered this hypothesis correspondences with observational data unfolded in a manner we had not seen before. It took us only a little time to confirm that bacteria are remarkably similar in their sizes to cosmic dust and that bacteria when they are fully dried out, as they would be in space would have optical scattering properties that are identical to the cosmic dust, at least in the visual spectral region. Starlight in the galaxy is dimmed due to scattering by grains over a wide range of visual wavelengths. The solid curve shows the predicted behaviour of the microbial model, indicating an uncannily close agreement with the astronomical data.
Perhaps the most dramatic confirmation of the bacterial model of cosmic dust came through observations made in the infrared spectral region. This next slide shows the remarkable correspondence between the observational points for the 2-4 micrometre spectrum of a source of cosmic infrared radiation located at the galactic centre, compared with the predicted behaviour of dried-out bacteria under simulated space conditions, a spectrum that was obtained ahead of the astronomical data becoming available.
One of the most remarkable developments in recent years involved the discovery of vast quantities of aromatic molecules, molecules based on hexagonal carbon-ring structures, which are evidently distributed quite extensively on a galactic and extragalactic scale. Needless to say, such molecules are part and parcel of biology, and their occurrence in interstellar space is readily understood as arising from the break-up of bacterial cells.
These correspondences, I hasten to add are only a selection from a much larger set that actually exist, and in our view go a long way towards establishing the essential microbial character of cosmic dust. On the basis of such comparisons we can estimate that throughout the Galaxy a total mass of 1033 tonnes of micro-organisms must exist in a freeze-dried condition at an average temperature of about 20 degrees above absolute zero.
It is a necessary consequence of this point of view that bacteria must be space-hardy, and so they are found to be. Bacterial spores in Archaeological sites are well known to survive for thousands of years, and last year bacteria encapsulated in the guts of this resin-trapped bee have been revived and cultured after some 25 million years. There is scarcely an end to the space survival properties of bacteria that are being unravelled. A viable strain of Streptococcus mitis, was recovered within a TV camera after two years of exposure to conditions on the surface of the moon. Bacteria can be taken down to near zero pressure and temperature, provided suitable care is exercised in the experimental conditions. They survive after exposure to pressures as high as 10 tonnes per square centimetre. Indeed colonies of anaerobic bacteria have recently been recovered from depths of 7 km or more in the Earth's crust. Bacteria survive after flash heating under dry conditions at temperatures up to 600 degrees Celsius. Viable bacteria have been recovered from the interior of an operating nuclear reactor.
Comets in the present scheme of things have a crucial role to play. They serve as sites of replication for primitive life, as well as vehicles for its transport. At the birth of our solar system, cometary bodies condensed at about the distance of the present planets Uranus and Neptune. We can argue quite convincingly that even the smallest population of cosmic bacteria present at the birth of this cloud of cometary bodies would have become vastly amplified within comets in their warm watery interiors on a very short time scale. When they subsequently cooled to become hard frozen, biology will have become trapped in a state of suspended animation.
Our point of view is that life on Earth began with the introduction of micro-organisms from comets. But this process could not have stopped at some distant time in the past for the simple reason that comets have been with us throughout. In our view the evolution of life must be controlled and directed by the continuing input of cometary debris in the form of bacteria, and fragments of bacteria that could be identified with viruses and viroids. It is well known that viral genes could on occasion be included in our genes, and that such genes could serve as potential for further evolution.
Let me now turn to some tests of this theory that might be contemplated at the present time. Let us first look at Mars, the only planet outside the Earth where one might expect life of some sort to survive at the surface. A search for primitive life forms was carried out by the US space agency NASA in the year 1976. Two spacecraft named Viking 1 and Viking 2 arrived at chosen spots on the Martian surface equipped to make in situ tests for bacterial life. In one experiment a nutrient broth of the sort that is normally used to culture terrestrial bacteria was poured onto a sample of Martian soil, and alas gases were found to froth out as would be consistent with the presence of microbial life. However, another experiment that sought to look for organic residues left by bacteria produced a negative or doubtful result. In 1976 NASA announced to the expectant world that the Viking experiments did not support the presence of bacterial life on Mars. Such a result accorded with the reigning paradigms in science, and so the matter may well have rested but it did not. In 1986 a careful re-examination of the same data combined with nearly a decade of laboratory experimentation led to the startling conclusion that primitive life could well exist in subsurface niches on this planet. Not only was it the case that the Viking experiments were not tested beforehand on the most inhospitable terrain on the Earth - the dry valleys of the Antarctic - until well after 1976, but when they were so tested results identical to the Martian results were obtained. The Antarctic dry valleys surely contain populations of bacteria, but their turn-over rate is so small that no organics were detectable by the Viking instruments. Levin and Straat, two scientists on the Viking biology team, further embarassed the establishment of NASA by announcing that all attempts to mimic the Martian results using non-biological models were unsuccessful. What is true for sure is that the results of the Viking experiments remain consistent with the existence of microbial life on Mars in suitable niches even at the present time.
During the past few days the existence of microbial life on Mars, at least in past epochs, appears to have been established beyond much doubt. A meteorite of Martian origin recovered on Earth has been found to contain evidence of fossilised micro-organisms, so microbial life must have existed on Mars some 3600 million years ago. It would appear most likely that both the Earth and Mars came to be seeded with bacterial life almost at the same time, so the ideas of panspermia become instantly validated.
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