The Complete Mars Trilogy: Red Mars, Green Mars, Blue Mars

Ann looked back and saw it, and was still. They watched the low banded clouds float overhead.

Finally a dinner call from the rovers brought them back. And walking down over the contoured terraces of sand, Nadia knew that she had changed – that, or else the planet was getting much more strange and beautiful as they traveled north. Or both.

They rolled over flat terraces of yellow sand, sand so fine and hard and clear of rocks that they could go at full speed, slowing down only to shift up or down from one bench to another. Occasionally the rounded slope between terraces gave them some trouble, and once or twice they even had to backtrack to find a way. But usually a route north could be found without difficulty.

On their fourth day in the laminate terrain, the plateau walls flanking their flat wash curved together, and they drove up the cleavage onto a higher plane; and there before them on the new horizon was a white hill, a great rounded thing, like a white Ayer’s Rock. A white hill – it was ice! A hill of ice, a hundred meters high and a kilometer wide – and when they drove around it, they saw that it continued over the horizon to the north. It was the tip of a glacier, perhaps a tongue of the polar cap itself. In the other cars they were shouting, and in the noise and confusion Nadia could only hear Phyllis, crying “Water! Water!”

Water indeed. Though they had known it was going to be there, it was still startling in the extreme to run into a whole great white hill of it, in fact the tallest hill they had seen in the entire five thousand kilometers of their voyage. It took them all that first day to get used to it: they stopped the rovers, pointed, chattered, got out to have a look, took surface samples and borings, touched it, climbed up it a ways. Like the sand around it, the ice hill was horizontally laminated, with lines of dust about a centimeter apart. Between the lines the ice was pocked and granular; in this atmospheric pressure it sublimed at almost all temperatures, leaving pitted, rotten side walls to a depth of a few centimeters; under that it was solid, and hard.

“This is a lot of water,” they all said at one point or another. Water, on the surface of Mars …

The next day the glacier hill formed their right horizon, a wall that ran on beside them for the whole day’s drive. Then it really began to seem like a lot of water, especially as over the course of the day the wall got taller, rising to a height of about three hundred meters. A kind of white mountain ridge, in fact, walling off their flat-bottomed valley on its east side. And then, over the horizon to the northwest, there appeared another white hill, the top of another ridge poking over the horizon, the base remaining beneath it. Another glacier hill, walling them in to the west, some thirty kilometers away.

So they were in Chasma Borealis, a wind-carved valley that cut north into the ice cap for some five hundred kilometers, more than half the distance to the Pole. The chasm’s floor was flat sand, hard as concrete, and often crunchy with a layer of CO2 frost. The chasm’s ice walls were tall, but not vertical; they lay back at an angle less than 45°, and like the hillsides in the laminate terrain, they were terraced, the terraces ragged with wind erosion and sublimation, the two forces that over tens of thousands of years had cut the whole length of the chasm.

Rather than driving up to the head of the valley, the explorers crossed to the western wall, aiming toward a transponder that had been included in a drop of ice-mining equipment. The sand dunes mid-chasm were low and regular, and the rovers rolled over the corrugated land, up and down, up and down. Then as they crested a sand wave they spotted the drop, no more than two kilometers from the foot of the northwest ice wall: bulky lime green containers on skeletal landing modules, a strange sight in this world of whites and tans and pinks. “What an eyesore!” Ann exclaimed, but Phyllis and George were cheering.

During the long afternoon, the shadowed western iceside took on a variety of pale colors: the purest water ice was clear and bluish, but most of the hillside was a translucent ivory, copiously tinted by pink and yellow dust. Irregular patches of CO2 ice were a bright pure white; the contrast between dry ice and water ice was vivid, and made it impossible to read the actual contours of the hillside. And foreshortening made it hard to tell how tall the hill really was; it seemed to go up forever, and was probably somewhere between three and five hundred meters above the floor of Borealis.

“This is a lot of water,” Nadia exclaimed.

“And there’s more underground,” Phyllis said. “Our borings show that the cap actually extends many degrees of latitude farther south than we see, buried under the layered terrain.”

“So we have more water than we’ll ever need!”

Ann pursed her mouth unhappily.

The drop of the mining equipment had determined the site of the ice mining camp: the west wall of Chasma Borealis, at longitude 41°, latitude 83° N. Deimos had just recently followed Phobos under the horizon; they wouldn’t see it again until they returned south of 82° N. The summer nights consisted of an hour’s purple twilight; the rest of the time the sun wheeled around, never more than twenty degrees above the horizon. The six of them spent long hours outside, moving the ice miner to the wall and then setting it up. The main component was a robotic tunnel borer, about the size of one of their rovers. The borer cut into the ice, and passed back cylindrical drums 1.5 meters in diameter. When they turned the borer on it made a loud, low buzz, which was louder still if they put their helmets to the ice, or even touched it with their hands. After a while white ice drums thumped into a hopper, and then a small robot forklift carried them to a distillery, which would melt the ice and separate out its considerable load of dust, then refreeze the water into one-meter cubes more suitable for packing in the holds of the rovers. Robot freight rovers would then be perfectly capable of driving to the site, loading up and returning to base on their own; and base would then have a regular water supply, larger than they could ever use. Around four or five trillion cubic kilometers in the visible polar cap, Edvard calculated, though there were a lot of guesses in the calculation.

They spent several days testing the miner and deploying an array of solar panels to power it. In the long evenings after dinner Ann would climb the ice wall, ostensibly to take more borings, although Nadia knew she just wanted away from Phyllis and Edvard and George. And naturally she wanted to climb all the way to the top, to get on the polar cap and look around, and take borings of the most recent layers of ice; and so one day when the miner had passed all the test routines, she and Nadia and Simon got up at dawn – just after two a.m. – and went out into the supercold morning air and climbed, their shadows like big spiders climbing before them. The slope of the ice was about 30°, steepening and then letting off time after time as they ascended the rough benches in the hill’s layered side.

It was seven a.m. when the slope laid back and they walked onto the surface of the polar cap. To the north was a plain of ice that extended as far as they could see, to a high horizon some thirty kilometers away. Looking back to the south they could see a great distance over the geometric swirls of the layered terrain; it was the longest view Nadia had ever had on Mars.

The ice of the plateau was layered much like the laminated sand below them, with wide bands of dirty pink contouring across cleaner stuff. The other wall of Chasma Borealis lay off to the east, looking almost vertical from their point of view, long, tall, massive: “So much water!” Nadia said again. “It’s more than we’ll ever need.”

“That depends,” Ann said absently, screwing the frame of the little borer into the ice. Her darkened faceplate turned up at Nadia: “If the terraformers have their way, this will all go like dew on a hot morning. Into the air to make pretty clouds.”

“Would that be so bad?” Nadia asked.

Ann stared at her. Through the tinted faceplate her eyes looked like ballbearings.

That night at dinner she said, “We really ought to make a run up to the pole.”

Phyllis shook her head. “We don’t have the food or air.”

“Call for a drop.”

Edvard shook his head. “The polar cap is cut by valleys almost as deep as Borealis!”

“Not so,” Ann said. “You could drive straight to it. The swirl valleys look dramatic from space, but that’s because of the difference in albedo between the water and the CO2. The actual slopes are never more than 6° off the horizontal. It’s just more layered terrain, really.”

George said, “But what about getting onto the cap in the first place?”

“We drive around to one of the tongues of ice that drop to the sand. They’re like ramps up to the central massif, and once there, we drive right to the pole!”

“There’s no reason to go,” Phyllis said. “It’ll just be more of what we see here. And it means more exposure to radiation.”

“And,” George added, “we could use what food and air we do have to check out some of the sites we passed on the way up here.”

So that was their point. Ann scowled. “I’m the head of the geological survey,” she said sharply. Which may have been true, but she was a horrible politician, especially compared to Phyllis, who had any number of friends in Houston and Washington.

“But there’s no geological reason to go to the pole,” Phyllis said now with a smile. “It’ll be the same ice as here. You just want to go.”

“Well?” Ann said. “Say I do! There are still scientific questions to be answered up there. Is the ice the same composition, how much dust – everywhere we go up here we collect valuable data.”

“But we’re up here to get water. We’re not up here to fool around.”

“It’s not fooling around!” Ann snapped. “We obtain water to allow us to explore, we don’t explore just to obtain water! You’ve got it backwards! I can’t believe how many people in this colony do that!”

Nadia said, “Let’s see what they say at base. They might want us to help with something there, or they might not be able to send a drop, you never know.”

Ann groaned. “We’ll end up asking permission from the UN, I swear.”

She was right. Frank and Maya didn’t like the idea, John was interested but noncommittal. Arkady supported it when he heard of it, and declared he would send a supply drop from Phobos if necessary, which given its orbit was impractical at best. But at that point Maya called mission control in Houston and Baikonur, and the argument rippled outward. Hastings opposed the plan; but Baikonur, and a lot of the scientific community, liked it.

Finally Ann got on the phone, her voice very curt and arrogant, though she looked scared: “I’m the geological head here, and I say it needs to be done. There won’t be any better opportunity to get onsite data on the original condition of the polar cap. It’s a delicate system, and any change in the atmosphere is going to impact it heavily. And you’ve got plans to do that, right? Sax, are you still working on those windmill heaters?”

Sax had not been part of the discussion and he had to be called to the phone. “Sure,” he said when the question was repeated. He and Hiroko had come up with the idea of manufacturing small windmills, to be dropped from dirigibles all over the planet. The constant westerlies would spin the windmills, and the spin would be converted to heat in coils in the base of the mills, and this heat would simply be released into the atmosphere. Sax had already designed a robotic factory to manufacture the windmills; he hoped to make them by the thousands. Vlad pointed out that the heat gained would come at the price of winds slowed down: you couldn’t get something for nothing. Sax immediately argued that that would be a side benefit, given the severity of the global dust storms the wind sometimes caused. “A little heat for a little wind is a great trade-off.”

“So, a million windmills,” Ann said now. “And that’s just the start. You talked about spreading black dust on the polar caps, didn’t you Sax?”

“It would thicken the atmosphere faster than practically any other action we could take.”

“So if you get your way,” Ann said, “the caps are doomed. They’ll evaporate and then we’re going to say, ‘I wonder what they were like?’ And we won’t know.”

“Do you have enough supplies, enough time?” John asked.

“We’ll drop you supplies,” Arkady said again.

“There’s four more months of summer,” Ann said.

“You just want to go to the pole!” Frank said, echoing Phyllis.

“So?” Ann replied. “You may have come here to play office politics, but I plan to see a bit of this place.”

Nadia grimaced; that ended that line of conversation, and Frank would be angry. Which was never a good idea. Ann, Ann …

The next day the Terran offices weighed in with the opinion that the polar cap ought to be sampled in its aboriginal condition. No objections from base; though Frank did not get back on the line. Simon and Nadia cheered: “North to the Pole!”

Phyllis just shook her head. “I don’t see the point. George and Edvard and I will stay down here as a back-up, and make sure the ice miner is working right.”

So Ann and Nadia and Simon took Rover Three and drove back down Chasma Borealis and around to the west, where one of the glaciers curling away from the cap thinned to a perfect rampway. The mesh of the rover’s big wheels caught like a snowmobile’s driving chain, running well over all the various surfaces of the cap, over patches of exposed granular dust, low hills of hard ice, fields of blinding white CO2 frost, and the usual lace of sublimed water ice. Shallow valleys swirled outward in a clockwise pattern from the pole; some of these were very broad. Crossing these they would drive down a bumpy slope that curved away to right and left over both horizons, all of it covered by bright dry ice; this could last for twenty kilometers, until the whole visible world was bright white. Then before them a rising slope of the more familiar dirty red water ice would appear, striated by contour lines. As they crossed the bottom of the trough the world would be divided in two, white behind, dirty pink ahead. Driving up the south-facing slopes, they found the water ice more rotten than elsewhere, but as Ann pointed out, every winter a meter of dry ice sat on the permanent cap to crush the previous summer’s rotten filigree, so the potholes were filled on an annual schedule; and the rover’s big wheels crunched cleanly along.

Beyond the swirl valleys they found themselves on a smooth white plain, extending to the horizon in every direction. Behind the polarized and tinted glass of the rover’s windows the whiteness was unmarred and pure. Once they passed a low ring hill, the mark of some relatively recent meteor impact, filled in by subsequent ice deposition. They stopped to take borings, of course. Nadia had to restrict Ann and Simon to four borings a day, to save time and keep the rover’s trunks from being overloaded. And it wasn’t just borings; often they would pass black isolated rocks, resting on the ice like Magritte sculptures: meteorites. They collected the smallest of these, and took samples from the larger ones; and once passed one that was as big as the rover. They were nickel-iron for the most part, or stony chondrites. Chipping away at one of these, Ann said to Nadia, “You know they’ve found meteorites on Earth that came from Mars. The reverse happens too, although much less often. It takes a really big impact to jack rocks out of Earth’s gravitational field fast enough to get them out here – delta V of fifteen kilometers per second, at least – I’ve heard it said that about two percent of the material ejected out of Earth’s field would end up on Mars. But only from the biggest impacts, like the KT boundary impact. It would be strange to find a chunk of the Yucatan here, wouldn’t it?”

“But that was sixty million years ago,” Nadia said. “It would be buried under the ice.”

“True.” Later, walking back to the rover, she said, “Well, if they melt these caps then we’ll find some. We’ll have a whole museum of meteorites, sitting around on the sand.”

They crossed more swirl valleys, falling again into the up-and-down pattern of a boat over waves, this time the largest waves yet, forty kilometers from crest to crest. They used the clocks to keep on a schedule, and parked from ten p.m. to five a.m. on hillocks or buried crater rims, to give themselves a view during their stops; and they blacked the windows with double polarization to help them to get some sleep at night.

Then one morning as they crunched along, Ann turned on the radio and began to run checks with the areosynchronous satellites. “It’s not easy to find the pole,” she said as she worked. “The early Terran explorers had a hell of a time in the north: they were always up there in summertime and couldn’t see the stars, and they had no satellite checks.”

“So how did they do it?” Nadia asked, suddenly curious.

Ann thought about it and smiled. “I don’t know. Not very well, I suspect. Probably dead reckoning.”

Nadia became intrigued by the problem, and started working on it on a sketchpad. Geometry had never been her strong point, but presumably at the north pole on midsummer’s day, the sun would inscribe a perfect circle around the horizon, never getting higher or lower. If you were near the Pole, then, and it was near Midsummer’s Day, you might be able to use a sextant to make timed checks on the sun’s height above the horizon … was that right?

“This is it,” Ann said.

“What?”

They stopped the rover, looked around. The white plain undulated to the nearby horizon, featureless except for a couple of broad red contour lines; the lines did not form bull’s eyes circles around them, and it didn’t look like they were at the top of anything.

“Where, exactly?” Nadia asked.

“Well, somewhere just north of here.” Ann smiled again. “Within a kilometer or so. Maybe that way.” She pointed off to the right. “We’ll have to go over there a ways and check with the satellite again. A little bit of triangulation and we should be able to hit it on the nose. Plus or minus a hundred meters, anyway.”

“If we just took the time, we could make it plus or minus a meter!” Simon said enthusiastically. “Let’s pin it down!”

So they drove for a minute, consulted the radio, turned to right angles and drove again, made another consultation. Finally Ann declared they were there, or close enough. Simon programmed the computer to keep working on it, and they suited up and went out and wandered around a bit, to make sure they had stepped on it. Ann and Simon drilled a boring. Nadia kept walking, in a spiral that expanded away from the cars. A reddish white plain, the horizon some four kilometers away; too close; it came to her in a rush, as during the black dune sunset, that this was alien – a sharp awareness of the tight horizon, the dreamy gravity, a world just so big and no bigger … and now she was standing right on its north pole. It was Ls = 92, about as near midsummer as you could ask; so if she stood facing the sun, and didn’t move, the sun would stay right in front of her face for all the rest of the day, or the rest of the week for that matter! It was strange. She was spinning like a top. If she stood still long enough, would she feel it?

Her polarized faceplate reduced the sun’s glare on the ice to an arc of crystalline rainbow points. It wasn’t very cold. She could just feel a breeze against her upraised palm. A graceful red streak of depositional laminae ran over the horizon like a longitude line. She laughed at the thought. There was a very faint ice-ring around the sun, big enough that its lower arc just touched the horizon. Ice was subliming off the polar cap and gleaming in the air above, providing the crystals in the ring. Grinning, she stomped her boot prints into the North Pole of Mars.

That evening they aligned the polarizers so that a very dimmed-down image of the white desert stood around them in the module windows. Nadia sat back with an empty food tray in her lap, sipping a cup of coffee. The digital clock flicked from 11:59:59 to 0:00:00, and stopped. Its stillness accentuated the quietness in the car. Simon was asleep; Ann sat in the driver’s seat, staring out at the scene, her dinner half-eaten. No sound but the whoosh of the ventilator. “I’m glad you got us up here,” Nadia said. “It’s been great.”

“Someone should enjoy it,” Ann said. When she was angry or bitter her voice became flat and distant, almost as if she were being matter-of-fact. “It won’t be here long.”

“Are you sure, Ann? It’s five kilometers deep here, isn’t that what you said? Do you really think it will completely disappear just because of black dust on it?”

Ann shrugged. “It’s a question of how warm we make it. And of how much total water there is on the planet, and how much of the water in the regolith will surface when we heat the atmosphere. We won’t know any of those things until they happen. But I suspect that since this cap is the primary exposed body of water, it’ll be the most sensitive to change. It could sublime away almost entirely before any significant part of the permafrost has gotten within fifty degrees of melting.”

“Entirely?”

“Oh, some will be deposited every winter, sure. But there’s not that much water, when you put it in the global perspective. This is a dry world, the atmosphere is super-arid, it makes Antarctica look like a jungle, and remember how that place used to suck us dry? So if temperatures go up high enough, the ice will sublime at a really rapid rate. This whole cap will shift into the atmosphere and blow south, where it’ll frost out at nights. So in effect it’ll be redistributed more or less evenly over the whole planet, as frost about a centimeter thick.” She grimaced. “Less than that, of course, because most of it will stay in the air.”

“But then if it gets hotter still, the frost will melt, and it will rain. Then we’ve got rivers and lakes, right?”

“If the atmospheric pressure is high enough. Liquid surface water depends on air pressure as well as temperature. If both rise, we could be walking around on sand here in a matter of decades.”

“It’d be quite a meteorite collection,” Nadia said, trying to lighten Ann’s mood.

It didn’t work. Ann pursed her lips, stared out the window, shook her head. Her face could be so bleak; it couldn’t be explained entirely by Mars, there had to be something more to it, something that explained that intense internal spin, that anger. Bessie Smith land. It was hard to watch. When Maya was unhappy it was like Ella Fitzgerald singing a blues, you knew it was a put-on, the exuberance just poured through it. But when Ann was unhappy, it hurt to watch it.

Now she picked up her dish of lasagne, leaned back to stick it in the microwave. Beyond her the white waste gleamed under a black sky, as if the world outside were a photo negative. The clockface suddenly read 0:00:01.

Four days later they were off the ice. As they retraced their route back to Phyllis and George and Edvard, the three travelers rolled over a rise and came to a halt; there was a structure on the horizon. Out on the flat sediment of the chasma floor there stood a classical Greek temple, six Dorian columns of white marble, capped by a round flat roof.

“What the hell?”

When they got closer they saw that the columns were made of ice drums from the miner, stacked on top of each other. The disk that served as roof was rough-hewn.

“George’s idea,” Phyllis said over the radio.

“I noticed the ice cylinders were the same size as the marble drums the Greeks used for their pillars,” George said, still pleased with himself. “After that it was obvious. And the miner is running perfectly, so we had some time to kill.”

“It looks great,” Simon said. And it did: alien monument, dream visitation, it glowed like flesh in the long dusk, as if blood ran under its ice. “A temple to Ares.”