At the beginning of the space age – at the moment when it became clear to all that Mars might indeed one day be experienced subjectively – the International Astronomical Union stepped in to clean up the planet’s increasingly baroque nomenclature. Thanks to the efforts of Schiaparelli, Lowell and Eugène Michael Antoniadi, whose beautifully drawn charts had become the standard, the planet had come to boast 558 names for an uncertain number of features. In 1958 the IAU experts settled on 128 named regions and features, with 105 of the names coming from Schiaparelli. Then the first spacecraft images came back and the stalwarts of the IAU needed not only more names but also new rules by which names could be assigned. It was at this point that the convention of naming craters for people with an interest in the planet was laid down. Proctor’s astronomical pantheon was reconvened – Dawes, Secchi, Mädler, Beer and the rest of them all got craters, as did Proctor himself.
And in 1972 the International Astronomical Union established for all time the precise location of the Martian meridian. Lacking a transit circle made of good Ipswich steel – or, for that matter, any ancient monuments – the IAU’s working group had to use a natural landmark for their zero. They chose the geometrical centre of a small, nicely rounded crater in the middle of a larger crater fifty-six kilometres across. They called that larger crater Airy.
There is a passage in the oeuvre of William F. Buckley Jr, in which he remarks that no writer in the history of the world has ever successfully made clear to the layman the principles of celestial navigation. Then Buckley announces that celestial navigation is dead simple, and that he will pause in the development of his narrative to redress forever the failure of the literary class to elucidate this abecederian technology. There and then – and with awesome, intrepid courage – he begins his explication: and before he is through, the oceans are in orbit, their barren shoals are bright with shipwrecked stars.
John McPhee, In Suspect Terrain
It was Merton Davies who put Airy in his prime position. Mert is a kindly man, tall and thin, dignified but rather jolly. Everyone who knows him speaks fondly of him. You might imagine him embodying decent reliability in a Frank Capra film even before learning that he has worked for the same outfit over more than fifty years. But it’s hardly been a small-town life. Mert Davies was one of the pioneers of spy satellites, one of the small cadre of technical experts who changed the facts of geopolitical life by letting cold warriors see the world over which they were at war from a totally new perspective. After that, he became one of only two people to have played an active role in missions to every planet save Pluto.* He has reshaped – quite literally – the way that earthlings see their neighbours in space. Davies is the man chiefly responsible for the ‘control nets’ of most of the solar system’s planets and moons – complex mathematical corsets that hold the scientific representations of those planetary surfaces together.
The first control net that he created served as the basis for the first maps of Mars made using data from spacecraft, rather than observations from earth. Compiled from fifty-seven pictures sent back when Mariner 6 and Mariner 7 flew past the planet in 1969, that first net tied together 115 points. When I met Davies in his office in Santa Monica thirty years later, his latest Martian control net held 36,397 points from 6320 images. Well into his eighties, Davies was still hard at work augmenting it further.
Davies had been interested in astronomy since boyhood, an interest he had shared with those close to him. In 1942, when he was working for the Douglas Aircraft corporation in El Segundo, California, he started courting a girl named Louise Darling. His interests made their dates a little unusual. Davies had started making a twelve-inch telescope, a demanding project. ‘I had a hard time finishing it,’ he recalls. ‘The amount of grinding it took and the difficulty of polishing that big a surface was a little bit over my head. I would take her with me to polish.’ And so she entered the world of grinding powder and the Foucault test, a simple but wonderfully precise way of gauging a mirror’s shape, which allows an amateur with simple equipment to detect imperfections as small as 50 billionths of a metre. Unorthodox courtship, but it worked. When I met Mert in 1999 he and Louise had been married for more than fifty years.
Just after the war, Davies heard that a think tank within Douglas was working on a paper for the Air Force about the possible uses of an artificial satellite. He applied to join the team more or less on the spot. The think tank soon became independent from Douglas and, as the RAND Corporation, it went on to play a major role in defining America’s national-security technologies and strategies throughout the Cold War. In the early 1950s Davies and his colleagues looked at ways to use television cameras in space in order to send back images of the Soviet Union. Then they developed the idea of using film instead of television – experience with spy cameras on balloons showed that the picture quality could be phenomenal – and returning the exposed frames to earth in little canisters. The idea grew into the Corona project, which after a seemingly endless run of technical glitches and launch failures at the end of the 1950s became a spectacularly successful spy-satellite programme.
While Corona was in its infancy, Davies was seconded to Air Force intelligence at the Pentagon, where he used the new American space technology to try to figure out what Russian space technology might be capable of. When he returned to Santa Monica in 1962, he was ready for a change. Spy satellites were no longer exciting future possibilities for think-tank dreamers, but practical programmes controlled by staff officers and their industry contractors. And there was another problem. ‘A lot of the work at RAND was going into Vietnam – my colleagues were working on reconnaissance issues there – and I wanted no part of that.’
Happily, an alternative offered itself in the form of Bruce Murray, an energetic young professor from the California Institute of Technology in Pasadena, on the other side of Los Angeles. Murray was an earth scientist, not an astronomer. His first glimpse of Mars through a telescope wasn’t a childhood epiphany in the backyard. It was a piece of professional work from the Mount Wilson Observatory. Late as it was, though, that first sight provided emotional confirmation for Murray’s earlier intellectual decision that the other planets were something worth devoting a lifetime’s study to. When Murray looked at Mars through the world-famous sixty-inch telescope, he was not just seeing an evocative light in the sky; he was seeing a world’s worth of new geology, a planet-sized puzzle that he and his Caltech colleagues were determined to crack. Their tool was to be the Jet Propulsion Laboratory, a facility that Caltech managed on behalf of the federal government. JPL, in the foothills of the San Gabriel mountains, had been a centre for military aerospace research since the war. In 1958 the Army ceded it to the newly founded National Aeronautics and Space Administration, as part of which it would become America’s main centre for planetary exploration. By 1961, JPL was planning NASA’s first Mars mission, Mariner 4. The man in charge of building a camera for it was Robert Leighton, a Caltech physics professor. He asked a geologist he knew on the faculty, Bob Sharp, to help him figure out what the camera might be looking at. Sharp asked his eager young colleague Murray to join the team.
Murray and Davies met in 1963; with three young children to support, Murray was keen for some extra income and so found consulting for RAND congenial. He and Davies quite quickly became close friends and Mert started to think he might want to get involved in Murray’s end of the space programme. After all, he had the right credentials: he had been in the space business since the days of the V2 and he had some experience in interpreting images of both the earth and moon as seen from orbit. (At the Pentagon he had analysed Russian pictures of the far side of the moon to see whether they might be fakes.) When Mariner 4’s television camera sent back its image-data – a string