Comet Terrain

Photos: ESA

What's interesting about the first close-ups of the surface of comet 67P/Churyumov–Gerasimenko (apart from the fact that they were taken by a robot spacecraft that has taken more than ten years to rendezvous with and go into orbit around an object currently plunging sunwards at 55,000km per hour) is that its landscapes aren't entirely alien. There are step terraces and a cirque of cliffs, a scattering of car-sized boulders and what looks like an alluvial plain, or perhaps a sheet of snow. Elsewhere there are craters, and rounded pits like sinkholes. Like the mountains and cliffs and plains of Saturn's icy moons, these features are composed of ice and dust rather than rock and soil, but although they are unearthly and formed by processes as yet unknown, they are not unrecognisable. Like the landscapes of the outer moons, there's something of the sublimity of icescapes of the Alps and Himalayas, the Arctic and Antarctic, in them. They are utterly remote from human experience, but they are something that the human imagination can appreciate and attempt to encompass. They are not exotic forbidden zones. They are destinations.