Green Mars(42)
She led them out into a viewing blister in the tent wall and, looking down between their feet, they could see through the blister’s transparent deck, straight down onto the caldera floor some five kilometers below them. People exclaimed in delicious fright, and Art bounced on the clear floor uneasily. The width of the caldera was coming into perspective for him; the north rim was just about as far away as Mount Tamalpais and the Napa hills when one descended into the San Jose airport. That was no extraordinary distance. But the depth below, the depth; over five kilometers, or about twenty thousand feet. “Quite a hole!” Adrienne said.
Mounted telescopes and display plaques with map drawings enabled them to spot the previous version of Sheffield, now lying on the caldera floor. Art had been wrong about the caldera’s untouched primeval nature; an insignificant pile of cliff-bottom talus, with some shiny dots in it, was in fact the ruins of the original city.
Adrienne described with great gusto the destruction of the town in 2061. The falling elevator cable had, of course, crushed the suburbs east of its socket in the very first moments of the fall. But then the cable had wrapped all the way around the planet, delivering a massive second blow to the south side of town, a blow which had caused an undiscovered fault in the basalt rim to give way. About a third of the town had been on the wrong side of this fault, and had fallen the five kilometers to the caldera floor. The remaining two-thirds of the town had been knocked flat. Luckily the occupants had mostly evacuated in the four hours between the detachment of Clarke and the second coming of the cable, so loss of life had been minimized. But Sheffield had been utterly destroyed.
For many years after that, Adrienne told them, the site had lain abandoned, a wreck like so many other towns after the unrest of ‘61. Most of those other towns had been left in ruins, but Sheffield’s location remained the ideal place for tethering a space elevator, and when Subarashii began organizing the in-space construction of a new one in the late 2080s, construction on the ground had rapidly followed. A detailed areological investigation had found no other faults in the southern rim, which had justified rebuilding right on the edge, on the same site as before. Demolition vehicles had cleared the wreckage of the old town, shoving most of it over the rim, and leaving only the easternmost section of town, around the old socket, as a kind of monument to the disaster— also as the central element of a little tourist industry, which had clearly been an important part of the town’s income in the fallow years before an elevator had been reinstalled.
Adrienne’s next point on the tour led them out to see this preserved bit of history. They took a tram to a gate in the east wall of the tent, and then walked through a clear tube into a smaller tent, which covered the blasted ruins, the concrete mass of the old cable facility, and the lower end of the fallen cable. They walked a roped path that had been cleared of wreckage, staring curiously at the foundations and twisted pipes. It looked like the results of saturation bombing.
They came to a halt under the butt end of the cable, and Art observed it with professional interest. The big cylinder of black carbon filaments looked nearly undamaged by the fall, although admittedly this was the part that had hit Mars with the least force. The end had jammed down into the Socket’s big concrete bunker, Adrienne said, then been dragged a couple of kilometers as the cable had fallen down the eastern slope of Pavonis. That wasn’t that much of a beating for material designed to withstand the pull of an asteroid swinging beyond the areosynchronous point.
And so it lay there, as if waiting to be straightened up and put back in place: cylindrical, two stories high, its black bulk encrusted by steel tracks and collars and the like. The tent only covered a hundred meters or so of it; after that it ran on uncovered, east along the wide rounded plateau of the rim, until it disappeared over the rim’s outer edge, which formed their horizon— they could see nothing of the planet below. But out away from the town they could see better than ever that Pavonis Mons was huge— its rim alone was an impressive expanse, a doughnut of flat land perhaps thirty kilometers wide, from the abrupt inner edge of the caldera to the more gradual drop-off down the volcano’s flanks. Nothing of the rest of Mars could be seen from their vantage point, so it seemed they stood on a high circular ring world, under a dark lavender sky.
Just to the south of them, the new Socket was like a titanic concrete bunker, the new elevator cable rising out of it like an elevator cable, standing alone as if in some version of the Indian rope trick, thin and black and straight as a plumb line dropping down from heaven— visible for only a few tall skyscrapers’ worth of height, at most— and, given the wreckage they stood in, and the immensity of the volcano’s bare rocky peak, as fragile-looking as if it were a single carbon nanotube filament, rather than a bundle of billions of them, and the strongest structure ever made. “This is weird,” Art said, feeling hollow and unsettled.