Over the lower end of the gallery was a sump and pump, and an insulated transport line leading to a small holding tank. Batteries would power the heating elements, and solar panels charge the batteries. When the holding tank was full, if there was enough water to fill it, the pump would shut off and a solenoid valve would open, allowing the water in the transport line to drain back into the gallery, after which the heating elements would shut off as well.
“Almost done,” Nadia declared late in the day, as she started to bolt the transport pipe onto the last magnesium post. Her hands were dangerously cold, and her maimed hand throbbed. “Maybe someone could start dinner,” she said. “I’m almost done here.” The transport pipe had to be packed in a thick cylinder of white polyurethane foam, then fitted into a larger protective pipe. Amazing how much insulation complicated a simple piece of plumbing.
Hex nut, washer, cotter pin, a firm tug on the wrench. Nadia walked along the line, checking the coupling bands at the joints. Everything firm. She lugged her tools over to Rover One, looked back at the result of the day’s work: a tank, a short pipe on posts, a box on the ground, a long low mound of disturbed soil running uphill, looking raw but otherwise not unusual in this land of lumps. “We’ll drink some fresh water on our way back,” she said.
They had driven north for over two thousand kilometers, and finally rolled down onto Vastitas Borealis, an ancient cratered lava plain that ringed the northern hemisphere between latitudes 60° and 70°. Ann and the other geologists spent a couple of hours every morning out on the bare dark rock of this plain, taking samples, after which they would drive north for the rest of the day, discussing what they had found. Ann seemed more absorbed in the work, happier. One evening Simon pointed out that Phobos was running just over the low hills to the south; the next day’s drive would put it under the horizon. It was a remarkable demonstration of just how low the little moon’s orbit was; they were only at latitude 69°! But Phobos was only some five thousand kilometers above the planet’s equator. Nadia waved goodbye to it with a smile; she would still be able to talk to Arkady using the newly arrived areosynchronous radio satellites.
Three days later the bare rock ended, running under waves of blackish sand. It was just like coming on the shore of a sea. They had reached the great northern dunes, which wrapped the world in a band between Vastitas and the polar cap; where they were going to cross, the band was about eight hundred kilometers wide. The sand was a charcoal color, tinged with purple and rose, a rich relief to the eye after all the red rubble of the south. The dunes trended north and south, in parallel crests that occasionally broke or merged. Driving over them was easy; the sand was hard-packed, and they only had to pick a big dune and run along its humpbacked western side.
After a few days of this, however, the dunes got bigger, and became what Ann called barchran dunes. These looked like huge frozen waves, with faces a hundred meters tall, and backs a kilometer wide; and the crescent that each wave made was several kilometers long. As with so many other martian landscape features, they were a hundred times larger than their terran analogs in the Sahara and Gobi. The expedition kept a level course over the backs of these great waves by contouring from one wave back to the next, their rovers like tiny boats, paddlewheeling over a sea that had frozen at the height of a titanic storm.
One day on this petrified sea, Rover Two stopped. A red light on the control panel indicated the problem was in the flexible frame between the modules; and in fact the rear module was tilted to the left, shoving the left side wheels into the sand. Nadia got into a suit and went back to have a look. She took the dust cover off the joint where the frame connected to the module chassis, and found that the bolts holding them together were all broken.
“This is going to take a while,” Nadia said. “You guys might as well have another look around.”
Soon the suited figures of Phyllis and George emerged, followed by Simon and Ann and Edvard. Phyllis and George took a transponder from Rover Three and set it out three meters to the right of their “road.” Nadia went to work on the broken frame, handling things as little as possible; it was a cold afternoon, perhaps seventy below, and she could feel the diamond chill right down to the bone.
The ends of the bolts wouldn’t come out of the side of the module, so she got out a drill and started drilling new holes. She began to hum “The Sheik of Araby.” Ann and Edvard and Simon were discussing sand. It was so nice, Nadia thought, to see ground that wasn’t red. To hear Ann absorbed in her work. To have some work to do herself.
They had almost reached the arctic circle, and it was Ls = 87, with the northern summer solstice only forty days away; so the days were getting long. Nadia and George worked through the evening while Phyllis heated supper, and then after the meal Nadia went back out to finish the job. The sun was red in a brown haze, small and round even though it was near setting; there wasn’t enough atmosphere for oblation to enlarge and flatten it. Nadia finished, put her tools away, and had opened the outer lock door of Rover One, when Ann’s voice spoke in her ear. “Oh Nadia, are you going in already?”
Nadia looked up. Ann was on the ridge of the dune to the west, waving down at her, a black silhouette against a blood-colored sky.
“That was the idea,” Nadia said.
“Come on up here just a second. I want you to see this sunset, it’s going to be a good one. Come on, it’ll only take a minute, you’ll be glad you did it. There are clouds to the west.”
Nadia sighed and closed the outer lock door.
The east face of the dune was steep. Nadia carefully stepped in the prints Ann had made in her ascent. The sand there was packed and held firm most of the time. Near the crest it got steeper, and she leaned forward and dug in with her fingers. Then she was clambering onto the broad rounded crest, and could straighten up and have a look around.
Only the crests of the tallest dunes were still in sunlight; the world was a black surface, marred by short scimitar curves of steely gray. Horizon about five kilometers off. Ann was crouching, a scoop of sand in her palm.
“What’s it made of?” Nadia asked.
“Dark solid mineral particles.”
Nadia snorted. “I could have told you that.”
“Not before we got here you couldn’t. It might have been fines aggregated with salts. But it’s bits of rock instead.”
“Why so dark?”
“Volcanic. On Earth sand is mostly quartz, you see, because there’s a lot of granite there. But Mars doesn’t have much granite. These grains are probably volcanic silicates. Obsidian, flint, some garnet. Beautiful, isn’t it?”
She held out a handful of sand for Nadia’s inspection. Perfectly serious of course. Nadia peered through her faceplate at the black grit. “Beautiful,” she said.
They stood and watched the sun set. Their shadows went right out to the eastern horizon. The sky was a dark red, murky and opaque, only slighty lighter in the west over the sun. The clouds Ann had mentioned were bright yellow streaks, very high in the sky. Something in the sand caught at the light, and the dunes were distinctly purplish. The sun was a little gold button, and above it shone two evening stars: Venus, and the Earth.
“They’ve been getting closer every night lately,” Ann said softly. “The conjunction should be really brilliant.”
The sun touched the horizon, and the dune crests faded to shadow. The little button sun sank under the black line to the west. Now the sky was a maroon dome, the high clouds the pink of moss campion. Stars were popping out everywhere, and the maroon sky shifted to a vivid dark violet, an electric color that was picked up by the dune crests, so that it seemed crescents of liquid twilight lay across the black plain. Suddenly Nadia felt a breeze swirl through her nervous system, running up her spine and out into her skin; her cheeks tingled, and she could feel her spinal cord thrum. Beauty could make you shiver! It was a shock to feel such a physical response to beauty, a thrill like some kind of sex. And this beauty was so strange, so alien. Nadia had never seen it properly before, or never really felt it, she realized that now; she had been enjoying her life as if it were a Siberia made right, so that really she had been living in a huge analogy, understanding everything in terms of her past. But now she stood under a tall violet sky on the surface of a petrified black ocean, all new, all strange; it was absolutely impossible to compare it to anything she had seen before; and all of a sudden the past sheered away in her head and she turned in circles like a little girl trying to make herself dizzy, without a thought in her head. Weight seeped inward from her skin, and she didn’t feel hollow anymore; on the contrary she felt extremely solid, compact, balanced. A little thinking boulder, set spinning like a top.