24th August 1997

Europa: is it high life or primordial sludge?

By Kamala Wickramasinghe

On April 9 1997, NASA made the startling announcement that there were signs of life on Jupiter’s moon, Europa. Close-up pictures taken by cameras aboard the spacecraft, Gallileo, revealed a network of ridges and valleys that curiously resembled a well-planned infrastructure. Could intelligent life- forms be cruising in rivers below the planet’s austere surface ? And what of the sprinkling of smooth, dark, football-pitch sized patches that can be seen in the close-up pictures ? Could they be sites for refuse incineration, which would lead to melting and re-freezing of the planet’s icy exterior ? The appearance of the surface of Europa uncannily smacks of intelligent control of the type portrayed in Arthur C. Clarke’s novel 2010.

Although the surface of Europa is made of hard, frozen ice at a temperature of -minus 100 degrees celsius, recent evidence has shown there are warm liquid oceans beneath a frozen crust. The life hinted at by NASA was not in the shape of little green men, but microscopic lifeforms of various kinds, swimming in an icy slush. However, if life exists in the depths of Europan oceans there is no absolute requirement that this life could only be in the form of humble microbes.

NASA’s claim that Europa’s inhabitants are merely tiny bacteria is based on the assumption that advanced life forms need a vast amount of oxygen to survive - an atmosphere which exists on the Earth. Yet deep-sea fish survive on the oxygen they draw from water and it could be the case that there are colonies of seafaring creatures under the surface of the ice who have adapted to aquatic conditions. In the oceans below Europa’s crust, the temperatures could be close to freezing, and Eskimos survive in climes that are not so different.

The scientist and science-fiction writer Arthur C. Clarke believes that Europa could be teeming with intelligent life: "Europa has now displaced Mars as the most fascinating body in the solar system. I am beginning to wonder if my description of it in 3001 The Final Odyssey did not go far enough - I only imagined fairly low life there, but some of the markings on the surface are very hard to explain. What’s going on here? I only hope that NASA will concentrate its resources on this fantastic world", he said. He thought that the actual form that Europan life would take was unimaginable as unimaginable as the diverse life-forms present on the Earth would be to non-Earthlings. Creatures of any shape or form living on, or close to Europa’s surface, could have acquired intelligence, said Clarke.

The question of how primitive our Europan neighbours actually are, is linked to the question of what has caused the ridges on the planet’s surface. NASA scientists believe that the ridges on the picture are the result of volcano-like eruptions from below the planet’s surface. But, according to the eminent scientist, Sir Fred Hoyle, such eruptions would not form such a regular and persistent path:

What is particularly astonishing about this picture is the large multiplicity of interlocking systems of parallel ridges that cross the surface of the moon, up to distances exceeding 100km in some cases. The separation of the ridges is typically about 1km, with the ridges themselves having distances no greater than about 180m. The essential feature of such systems is that they have an uncanny persistence. They cross over one another, maintaining their identities over distances of tens of kilometres, distances very large compared to their individual widths. The lack of evidence for cratering further suggests that the surface is being more or less continually re-worked.

"With any linear structure we can chose two widely separated places, A and B say, and we ask the question : What is the structure that connects A and B? With a metal bar it is the strength of the metal connection. With a rope it is the details of how the rope is stretched that connected A and B. The NASA caption for the close-up pictures of Europa, uses the analogy of a highway, perhaps without realising the implications of such an analogy. Since for a highway it is the plan of the road builder that connected A to B ," he said.

The debate amongst scientists as to the nature of extra-terrestial life, has only recently superseded the debate of whether life actually exists outside the Earth. And until the 70’s, the interesting question of whether there is life on other planets was very much a sub-culture in Western thought. The idea that the Universe swarms with life, and that the Earth is just one small part of a bigger system, was first put forward by Aristarchus of Samos in the 3 C BC.

His speculation, which came into conflict with earth-centred religions, was unpopular and remained dormant for many centuries.

In the 19th century, the issue was re- opened up by several prestigious scientists including Lord Kelvin, John Tyndall, W.Helmholtz and Swante Arrhenius. Their lively debates which advanced a powerful case for the existence of life in the Universe were, however, overshadowed in history by another brain-child of science which was shaking up the status quo of Western thought : Darwinism.

During the last 25 years, the debate has slowly moved to the forefront of science. God is more or less officially dead and new technology has made the exploration of space possible and given new credence to an area that was previously based on the imaginative speculation of a handful of radicals.

Journeys into space and planetary explorations have been carried out by NASA probes and spacecrafts, and one of NASA’s declared objectives is to search for life outside the Earth. Yet, despite this claim , NASA scientists have been less than willing to endorse the full implications of their findings. In 1976 a multi-billion dollar project was involved in sending equipment to Mars (the Viking project) in search of active microbial life. One of the experiments was to pour nutrients on Martian soil and see if there were any signs of life. The two principal scientists involved in this project, Gilbert Levin and Patricia Straat, later announced that life was decisive from these experiments - the soil frothed up when nutrient was poured, releasing the same gases bacteria release when they reproduce. Yet NASA vehemently denied that life existed on Mars.

The climate of opinion changed unexpectedly in August last year when NASA scientists made a complete U-turn to declare that there was evidence of life (albeit microscopic and fossilised) on a meteorite from Mars that landed on the Earth. This evidence would seem to be scant compared to the 1976 evidence for extra- terrestial life that was repeatedly denied. After all, there was no absolute guarantee that the meteorite actually came from Mars and the fact that the bacteria was fossilised ruled out any galvinising experiments.

What happened in 1996 for this dramatic mood swing on the part of NASA is a million dollar question that remains unanswered. It could be that they suddenly became aware that the discovery of extra-terrestial life would win public support, causing an increase to NASA’s grants. For this area of science cannot fail to stir human interest as it is ultimately seeking to establish Man’s place in a wider Universe - an endeavor which overlaps with the speculations of literature, philosophy and religion.

NASA’s 1969 project of Man on the Moon has been Science’s most popular gesture to date and it revolutionised the way the ordinary person thought about science. It became fun, daring, and had an accessible message. And the success of this project was in creating the impression that Man was the supreme ruler of the Universe. That once numinous stone, erstwhile symbol of romantic love, became nothing more than a rock on which Man could stomp triumphantly. But perhaps NASA’s next big public success will oust Man from his privileged position by the discovery that he is only one (and maybe not the most advanced) of many intelligent life-forms in the Universe.

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