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One day an exploring party came back from the north, excited. Seventeen kilometers to the north of their landing site, there was an anomaly in the generally straight and cliffed coast, a small semicircular valley that opened onto the sea. This was a feature that had been visible from the ship, of course, and people still on the ship had reminded the surface party about it, and now this group had hiked up to visit it, and having seen it, had come back to base exclaiming its virtues.

It was either an old impact crater or an extinct volcanic feature, but in any case, a semicircular depression in the burren, with the straight side of the semicircle a beach fronting the sea. The explorers called it Half Moon Valley and said its beach was composed of sand and shingle, backed by a lagoon. In the low land behind the lagoon an estuary cut through the valley, then rose through a break in the low cliff of the burren, first as a braided, gravel-bedded river, then as a set of swift tumbling rapids. And the entire valley, they said, was floored with soil. From space this soil appeared to be loess. The explorers’ closer inspection had indicated it was a combination of loess, sea sand, and river silt. Calling it soil was perhaps inaccurate, as it was entirely inorganic, but at the very least it was a soil matrix. It could quickly be turned into soil.

This was such promising news that the settlers quickly decided that they should move there. They freely admitted that one powerful attraction was the possibility of getting out of the wind. But there were other advantages as well: access to the ocean, a good supply of fresh water, potential agricultural land. The prospect was so enticing that some of them even wondered why they hadn’t landed there in the first place, but of course they were reminded by people in the ship (who had been reminded by the ship) that the robotic landers had had to give the valley a wide berth, to be sure they came down on flat rock.

Now they were safely down, and in exploration mode, and their settlement was still quite mobile, being almost entirely composed of landers; they had built their wind wall but not yet started on buildings. So they could make the move fairly easily.

Over the next few days, therefore, everyone in the station walked up to see the sea valley, and agreed the moment they did that the move should be made. This kind of unanimity was said to have happened so infrequently on the ship (in fact it had never happened) that the people still on the ship were happy to accede to the plan on the ground.

“As if we could stop them,” Freya remarked to Badim.

Badim nodded. “Aram says they are acting ominously autonomously. But it’s okay. We’ll all be down there soon. And it looks like a good place.”

At this point, people from the ship were being ferried down to the moon in modules that then served as their living quarters. Nothing was going as quickly as many on the ship would have liked, but everyone had to agree that nothing more could be done to speed the process. They only had so many ferries, and then some had to be refueled and launched back up to ship. Now that they were going to move the settlement to Half Moon Valley, all the work to expand their living space would be delayed. But a brief delay was felt to be well worth it, given the many advantages that would follow the move.

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So the settlers got to work moving, a task that seemed easy until they began to do it, when the little declivities and breaks in the burren turned out to be more obstructive to moving their living modules than had been foreseen. The shallow little grabens were easy to walk down small ravines into and out of, and so they had hiked to the valley and back without impediment, but moving their modules on wheeled frames, and their construction robot vehicles, and even their rovers, across them was not so easy. And the grabens were all so long, and trending east-west, that they often could not be flanked.

A best route was found that crossed as few of these troughs as possible, using the algorithm that solves the traveling salesman problem, notorious to all those worried about errors endemic to certain greedy algorithms. But even after extensive cross-checking, the minimum number of graben crossings turned out to be eleven. Each trough had to be bridged, and this was not easy, given the dearth of bridge materials and the weight of the loads on the wheeled carts.

So it was a slow and ponderous trek, and soon after they began, sunset came again. They did not let this stop them, having decided they could make their trip by the light of E. It hung up there in its usual spot, half illuminated—what on Earth they called a quarter moon, an unusually logical name, it must be said. Just after sunset was as dark as the nights got, as E waxed to full and then waned to the other quarter moon before sunrise. The light cast by quarter E was around 25 lux, which was 25 times the illumination of the full moon on Earth; and though it was four thousand times less than direct sunlight on Earth, and six thousand times less than full taulight on Aurora, it was still about the same illumination as a nicely lit room at night in the ship, which was certainly enough to see by. So they worked in this light, and formed a long caravan of their vehicles, and headed north over the burren. In the end they declared the E light quite beautiful, easy on the eyes, things slightly drained of color but extremely distinct.

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Euan and the rest of the bridge-building team went into action when they came to the edge of the first trough. One of them drove a stone-cutting vehicle to the edge of the trough, well away from where they intended to cross, and put to work a rock saw attachment at the end of the vehicle’s backhoe. Cubes of rock were cut from the side of the graben, then lifted and conveyed hanging from the backhoe to a steep-walled section of graben, where the opposite side was both close and as vertical as could be found. The first cube was hard to get loose, but with some knocking with the side of the backhoe they managed it. Cubes three meters on a side were as large as the vehicle could safely lift. When they got them to the edge of the graben they lowered them into the trough, all very slowly, especially if the wind was gustier than usual. Every four or five cubes, they had to stop and swap out the saw blades they were using, both the circular blades and the thin up-and-down saws that Euan called dental floss. Their printer refurbished worn blades with new synthetic diamond edges, and they attached these and continued cutting cubes and depositing them in the trough to make a rough ramp. When the ramp extended far enough into the trough that the vehicle arm couldn’t reach out far enough to place new cubes, they filled the gaps between cubes with gravel that other teams had crushed, then unrolled by hand an aluminum mesh carpet to provide a bridge surface smooth enough to drive onto. Euan then drove the cutter vehicle out onto this ramp, another cube dangling heavily from its front end, everything looking precarious, especially when swaying in hard gusts of wind, until he reached the leading edge of the new ramp and could lower the next cube of rock into place.

They were nearly done with this first ramp when Eliza dropped a new cube into place without realizing the trough bottom was not smooth. This was perhaps a result of them working in E light, but in any case, the new cube tilted into another cube already in place in a way that meant their vehicle could neither lift it nor move it, without dangerously tipping the vehicle.