Life on Mars?

To the naked eye Mars is unmistakeably red, the colour of blood and, by association, of war, and its light fluctuates in intensity as it wanders one way and then back again across the sky. It has been an object of fascination and speculation for all recorded history. Looking through a telescope more than a hundred years ago, Percival Lowell thought he spotted canals on Mars and hypothesised the existence of intelligent life, desperately building canals to fight off the encroaching desert. (The canals were in the first instance a mistranslation of the canali – channels – detected by the Italian astronomer Giovanni Schiaparelli.) Lowell was wrong, and although Mars is covered in spectacular geological features, his canals aren’t one of them. We know, because we’ve looked. At the time of writing there are three spacecraft orbiting Mars and three more trundling about its surface. The latest is a Nasa lander called Phoenix, resident on Mars since 25 May, which is currently chugging around the north polar region looking for water and evidence of habitability.

This is impressive, given how hard it is to get to Mars. A total of 20 probes, Russian, Japanese, American and European, have crashed on their way to the red planet. They’ve crashed on take-off, crashed on landing, conked out of power, or, in the case of Nasa’s Mars Climate Orbiter in 1999, burned up on entry into the Martian atmosphere because the contractor, Lockheed Martin, had confused imperial and metric measurements. That would be an embarrassing thing to get wrong when buying a pair of trousers. Cost of mistake: $327.6 million.

The central question about Mars is whether it can support life; and since life, as far as we know, requires water, the immediate issue is whether Mars has water. Since the first mission to Mars, Nasa’s Mariner 4 in 1964, a considerable body of evidence has accumulated to suggest that it does, or did. All six of the currently functioning Martian probes have found evidence of it. On 19 June, Nasa published the strongest direct evidence yet: before-and-after photographs taken by Phoenix, showing that a substance resembling ice had disappeared as it warmed up. (Because of the atmospheric conditions, water ice doesn’t melt on Mars; it ‘sublimes’ and turns straight into gas, just as CO2 on earth goes straight from ‘dry ice’ to gas with no liquid stage in between.) Now, though, we have moved beyond evidence to the thing itself: on 31 July, Nasa announced that Phoenix’s robot arm had dug up what is unquestionably water ice. ‘We’ve seen evidence for this water ice before,’ the lead scientist on the mission said, ‘but this is the first time Martian water has been touched and tasted.’ Water on Mars! For real! Amazing!

Except nobody is amazed. The reaction was muted to non-existent. It’s not that nobody cares, exactly; it’s that the only people who care are the ones who cared already. To those who do care, it’s frustrating. The Phoenix mission is a search into the fundamental mystery of whether human beings are alone in the universe – a subject of some general interest, one might have thought. The idea is that by investigating the presence and history of water on Mars we can begin to consider the question of whether or not life existed there; which in turn would provide powerful evidence of the probability that life exists elsewhere in the universe. Why look for water, and not life directly? Because a mission that found life would first have to prove that there was zero probability it had been contaminated by contact with organic matter on Earth; and to get that probability down to zero would be prohibitively difficult and expensive. So it comes down to a question of cost.

Perhaps that’s the nub of the general lack of interest. Robotic space exploration is safer and cheaper than the manned version, and the science it does is very good (some say better). But it is not as dramatic as manned space flight, and that, in the age of news-as-entertainment, is a problem. The truth is that there are now superb tools for the ordinary punter interested in astronomy and space. The Nasa website is one of the wonders of the world. The supply of information is particularly compelling because the ordinary punter can tap into it directly: you can get your Nasa news unmediated, or at least unmediated by anyone other than Nasa.

Whether this helps to provoke any interest in the uninterested is another question. You would have to assume, on the evidence, that the answer is no. The scientific project more likely to do that, perhaps, is the Conseil Européen pour la Recherche Nucléaire (Cern), where the European Large Hadron Collider goes into action for the first time on 10 September. Though no one understands fundamental physics it’s easy to grasp the idea of what Cern is doing: smashing bits of atoms apart in order to find yet smaller bits. There is a sublimity to Cern’s search for the Higgs boson. This particle is predicted by the ‘standard model’ of subatomic physics; it’s the only particle in the standard model not to have been directly observed, which is a big deal, because the Higgs boson is the explanation for why matter has mass. (Many particles have no mass, and yet the matter made out of them does. The Higgs boson is, it is thought, responsible for the missing mass.) Also sublime is the sheer scale of the project: a 17-mile circular tunnel, 100 metres under the Alps, whose interior has been cooled to a temperature of -271 ºC, a degree and a bit above absolute zero. The cost is pretty sublime too, a cool £4.4 billion.

In 1993, the US Congress cancelled the equivalent programme in the US, to build the SSC or Superconducting Super Collider in Texas. The SSC was to be a tunnel 54 miles in diameter, of which 14 miles were built before the funding was pulled. One of the arguments used by opponents of the SSC was that the US couldn’t afford both it and Nasa’s contribution to the International Space Station. The subplot seems to have been the fact that the SSC concentrated its spending in Texas, whereas Nasa were able to spread contracts around, with consequently wider congressional support. So they got the space station, and we got the Large Hadron Collider. It will take a longish timescale to judge whether the US or Europe spent its money more wisely. But there has never been a better time to be interested in the questions of whether we’re alone, and what everything is made of. As for the mystery of why more of us aren’t interested – that’s not so easy.