life on mars

With a recent study by Edinburgh University claiming there is probably intelligent life elsewhere in the cosmos, and recent scientific discoveries pointing to the possibility of life on other worlds in our solar system, Steve Arnott explores some of the evidence and asks just what would it mean if there really is Life on Mars?

‘Life on Mars!’ screamed the Sun headline. ‘At least something up there is causing all that wind’ they added in brackets.

A story that was treated with the proper restraint by most of the media became a headline grabber for the Murdoch flagship, perhaps over eager for a ‘scoop’ on the rest of the journalistic world. Of course, what had been found by NASA scientists was not ‘proof’ of life on Mars at all, at least not in the sense of incontrovertible and unchallengeable proof. What they had found was compelling evidence that indicated the real possibility of simple microbial life on Mars, yet another piece in a scientific jigsaw puzzle that increasingly points to the intriguing ‘perhaps’ of life existing, or having existed at one time, on the Red planet.

Essentially there are only three possible explanations for the existence of these plumes

2) frozen methane created by extinct organisms gradually being released into the atmosphere by seasonal warming – but such a ‘store’ of methane would be expelled and dissolved rapidly in geological terms unless it had a means of renewing itself, or

3) the metabolic action of existing life forms (probably simple) living on or below the surface of Mars.

Compared to the rich collective cultural mythos relating to fictional life on Mars, from the ‘canals’ glimpsed by Edwardian astronomers, H.G. Wells’ tripod invaders and the boy’s own imagery of Edgar Rice Burroughs, right through to Arnie blasting away the bad guys in Total Recall, the possibility of belching microbes on Mars may not seem so exciting. After all, we are the Star Wars and Doctor Who generation. Like African-American Presidents of the USA, the idea of aliens is one that has been normalised in our culture through films, books and TV. It would perhaps be understandable that an underwhelmed public might expect news of alien life to be about the proverbial bug eyed monster, and not more prosaically about, well…bugs.

But life is life, and the discovery of its existence off-planet, however basic in form, would be epoch making. The recent methane discovery is only one in a number of indicators that have come to light in the last 10-15 years that appear to be tipping the balance of evidence in favour of life existing or having had existed at one time on our nearest planetary neighbour.

In 1996, a group of scientists from NASA’s Johnson Space Centre published a paper in Science magazine which received world wide publicity. The paper outlined evidence for fossilised life found in the meteorite ALH84001, which landed in the Antarctic over 13, 000 years ago, having been ejected into space from Mars after a large meteorite impact some 16 million years ago (if you want to know how scientists could possibly work all this out from a rock google ‘evidence of ancient martian life in meteorite ALH84001'.

Although trumpeted at the time by the media and no less a personage than then US President Clinton as ‘proof’ of life on Mars, the actual scientists involved in the research were very much more circumspect and careful in their presentation of the evidence, claiming only that the three possible indicators of microbial life found in the meteorite were strong evidence pointing towards primitive bacterial life. These three indicators were

This was followed by a series of discoveries of water or water flow features on Mars. It has long been known that water was locked up in the icy Martian poles, and it was considered eminently possible that water existed as permafrost under the martian surface. A number of groups looking at the geology of the Red planet from satellite images drew the conclusion that a number of features could only be explained by large bodies of water flowing over the Martian surface at some point in the deep geological past. Although this view is by no means universal, it has gained widespread acceptance over the last few years.

Then Canadian researchers from Guelph University in Toronto, led by Professor Iain Campbell, looking into samples of soil from the Mars Spirit rover found water trapped in the Martian surface (at the sampled part) with a concentration of up to 16%.

“The Mars rovers looking at the geology and the geochemistry have strong proof for water in the geological past,” Professor Campbell said at the time of the discovery. “The orbiting satellites have got very strong evidence for water in the present. Our measurement is the first quantative measurement of water in a well-defined lump of material on the surface of the planet.”

Water is, of course, one of the fundamental pre-requisites for life (at least as we know it, Jim.)

None of this is yet the ‘smoking gun’ kind of proof of life that scientists are looking for, but collectively it is beginning to build up a reasonable case that there is probably something there. Will that ‘smoking gun’ be found in our lifetime? My advice is don’t bet against it.

As the world celebrates the 200^th anniversary of the birth of Charles Darwin, a plethora of television documentaries and magazine articles have investigated and analysed his theory of natural selection, and celebrated the now undisputed scientific fact (the dim-witted views of creationist cranks excepted) of the evolution of countless diverse and complex organisms across the face of the Earth from simple single celled life over the period of the last three billion years.

No-one seriously doubts these days either the huge body of evidence for evolution, or the ability of the modern Darwinian synthesis to account scientifically for life on Earth in all its aspects. The question still arises, however, as to whether life only ever got started on this single speck of planetary dust orbiting our sun – one of 400 billion stellar systems in this galaxy alone – or whether the shift from organic chemical compounds to organic replicators, which then come under selection pressures and are opened up to the dynamic evolutionary process, is a much more common process throughout the universe.

Probably the majority view in science now is that it would be statistically very surprising if the former was true. If proof of life, even very simple cellular life, existing on or ever having had existed on another world was found, it would mean, in conjunction with all the other evidence, that the probability would be vastly increased that life was a fairly widespread and common phenomena throughout the universe. The number of extra-solar planets already discovered orbiting other suns (now around 400), the sheer number of stars out there (more than the number of grains of sand currently on planet Earth), and the fact that natural selection is a universal, not local process, in principle, would make it highly likely that other conscious and intelligent species of life, including advanced alien societies, exist right now in our galaxy, concurrently to ourselves, separated from us epistemologically only by the vast, deep light year distances of time and space.

Based on a modern version of the famous Drake equations, taking into account the relatively recent discovery of the abundance of extra solar planets and assuming that life could exist only in the so-called ‘Goldilocks’ zone of orbit around a star (not too cold, not too hot) in which an earth like world could develop, Edinburgh University researchers recently concluded that the likelihood was that between 300 and 38,000 advanced civilisations existed in our galaxy alone. These figures did not take into account the now seriously discussed possibilities of life existing elsewhere in our solar system outside the ‘Goldilocks’ zone, such as on Mars, or possibly beneath the ice of Jupiter’s moon, Europa.

The discovery of life on Mars or any other non-terrestrial body – whether living or long extinct – would blow away the last vestiges of the supernatural view of the world and bring an end to the idea of Earth as unique, and humankind as some favoured, special and unique aspect of creation. It would mean a cultural and scientific paradigm shift where we would have to start to seriously concede the likelihood that Homo sapiens may be but one conscious and intelligent species among many others still potentially to be encountered or discovered.

The discovery of life on Mars could be the first step down a whole new existential road for our species, and perhaps the only way to find out for sure whether or not life exists on Mars is to go there and see for ourselves.

The new American President, Barack Obama, likes to echo liberal political heroes from America’s past, such as Martin Luther King or John F. Kennedy. He could do worse than echo JFK’s commitment to put a man on the moon within 10 years, made in1963, and commit to a international manned expedition to Mars by 2025.

Such a thing would be costly to be sure, but probably less costly and more ultimately productive than bailing out failed bank after failed bank to the tune of trillions of dollars. Many socialists traditionally, almost as a knee-jerk reaction, object to space exploration when we have so many outstanding problems here on Earth. There is a non-religious sense, however, in which humankind cannot, and should not, live by bread alone.

We use the technological spin-offs from the Apollo missions in our everyday lives. We were, as a species, immeasurably culturally enriched when Neil Armstrong stepped onto the surface of the Moon – over 40 years ago now.

A manned expedition to Mars would be a great communal adventure for all humankind, and if microbial life exists or has existed on Mars, then the most important fact since natural selection itself lies in wait there to be discovered.