In the early 1950s, a huge hole was dug into the Cumbrian coast and lined with concrete. Roughly the length of three Olympic swimming pools and known as B30, it was built to hold skip loads of spent nuclear fuel. Those highly radioactive rods came from the 26 Magnox nuclear reactors that helped keep Britain's lights on between 1956 and 2015. When B30 was first put to work, it was designed to keep the fuel rods submerged for only three months before reprocessing work was carried out. But when 1970s miners' strikes shut down coal power stations and forced greater reliance on nuclear plants, more spent fuel than could be quickly reprocessed was generated.

If you take the cosmic view of Sellafield, the superannuated nuclear facility in north-west England, its story began long before the Earth took shape. About 9bn years ago, tens of thousands of giant stars ran out of fuel, collapsed upon themselves, and then exploded. Flung out by such explosions, trillions of tonnes of uranium traversed the cold universe and wound up near our slowly materialising solar system. And here, over roughly 20m years, the uranium and other bits of space dust and debris cohered to form our planet in such a way that the violent tectonics of the young Earth pushed the uranium not towards its hot core but up into the folds of its crust. Within reach, so to speak, of the humans who eventually came along circa 300,000BC, and who mined the uranium beginning in the 1500s, learned about its radioactivity in 1896 and started feeding it into their nuclear reactors 70-odd years ago, making electricity that could be relayed to their houses to run toasters and light up Christmas trees. Sellafield compels this kind of gaze into the abyss of deep time because it is a place where multiple time spans – some fleeting, some cosmic – drift in and out of view. Laid out over six square kilometres, Sellafield is like a small town, with nearly a thousand buildings, its own roads and even a rail siding – all owned by the government, and requiring security clearance to visit. Sellafield's presence, at the end of a road on the Cumbrian coast, is almost hallucinatory. Then, having driven through a high-security gate, you're surrounded by towering chimneys, pipework, chugging cooling plants, everything dressed in steampunk. The sun bounces off metal everywhere. In some spots, the air shakes with the noise of machinery. It feels like the most manmade place in the world. Since it began operating in 1950, Sellafield has had different duties. First it manufactured plutonium for nuclear weapons.

Delivering a rover to the surface of a distant icy world like Jupiter's moons Europa and Titan is only half the challenge. Once on the surface, the robotic explorers will have to contend with intense space radiation, plunging temperatures that drop to hundreds of degrees below zero and miles upon miles of ice before hitting the subsurface oceans that astronomers suggest may contain life. But NASA has a plan. "Robotic systems would face cryogenic temperatures and rugged terrain and have to meet strict planetary protection requirements," Hari Nayar, of NASA's jet propulsion laboratory, said in a statement. "One of the most exciting places we can go is deep into subsurface oceans -- but doing so requires new technologies that don't exist yet."