They say that if you look at it closely, the sky forms the visual equivalent of a dome overhead. Not a true hemisphere, but flattened somewhat. This is a virtually universal human perception, the result of consistent overestimation of horizontal distance compared with vertical distance. On Earth the horizon seems to be two to four times farther off than the zenith overhead, and if you ask someone to divide the arc between the zenith and the horizon evenly, the point chosen averages well less than forty-five degrees; about twenty-two degrees by day, I have found, and thirty by night. Redness increases this effect. If you look at the sky through red glass it appears flatter; if through blue glass, taller.
On Mars the unobstructed horizon is only about half as far away as it is on Earth—about five kilometers—and sometimes this simply makes the zenith seem even lower—perhaps two kilometers high. It depends on the clarity of the air, which of course varies a great deal: Sometimes I have seen the dome of the sky appear ten kilometers high, or even transparent to infinity. Mostly lower than that. In fact the vault of the sky is a different shape every day, if you will take the time to look at it carefully.
But no matter the transparency of the sky, or the shape of the dome it makes overhead: The sand is always the same. Flat; reddish brown; redder out toward the horizon. The characteristic redness occurs if even one percent of the bedrock or the dust on the ground is made up of iron oxides such as magnetite. This condition obtains everywhere on Mars, except for the lava plains of Syrtis, which when blown free of dust are nearly black—one of my favorite places (also the first feature to be seen from Earth through telescopes, by Christiaan Huygens in 1654).
In any case: a perfect red plane in all directions, to the round horizon. Inside certain flat craters, you stand at the center and see a double horizon, in fact: the lower one five kilometers away, and perfectly straight; the higher one farther away, and usually less straight, even serrated. (This second horizon also considerably flattens the dome of the sky.)
But the completely flat areas are the purest view. Much of Vastitas Borealis is so flat that only millions of years of existence as the floor of an ocean can explain it. And parts of Argyre Planitia are equally flat. We cannot lose these places. In these regions one stands confronted by a radically simplified landscape. It is a surreal experience to look around oneself—surreal in the literal sense of the word, in that one seems to stand in a place “over-real,” or “more than real"—a higher state than reality; or reality revealed in its barest, most heraldic simplicity. The world says then, This is what the cosmos consists of; rock, sky, sun, life (that's you). What a massive aesthetic impact is conveyed by this so-simplified landscape! It forces you to pay attention to it; it is so remarkable you keep looking at it, you cannot do or think anything else—as if living in a perpetual total eclipse, or within any other physical miracle. Which of course is always the case. Remember.
Maya and Desmond
1. Finding Him
After she saw the strange face through the bottle in the farm of the Ares, Maya couldn't stop thinking of it. It frightened her, but she was no coward. And that had been a stranger, not one of the hundred. There on her ship.
And then she told John about it, and he believed her. He believed in her; and so she was going to have to track that stranger down.
She began by calling up the plans for the ship and studying them like she had never studied them before. It surprised her to find how many spaces it contained, how large their total volume. She had known the areas the way one knows a hotel or a ship or a plane, or one's hometown for that matter—as a set of her life-routes, wound through the whole in an internal mental map, which itself could be called up sharply visible in her mind's eye; but the rest was only vagueness, deduced, if she ever thought about it, from the parts she knew; but deduced wrongly, as she now found out.
Still, there was only so much livable space in the thing. The axis cylinders were not livable, by and large, and the eight toruses were, for the most part; but they were also very heavily traveled. Hiding would not be easy.
She had seen him in the farm. It seemed possible, even perhaps likely, that the man had allies in the farm crew, helping him to hide. A lone stowaway, unknown to anyone aboard, was difficult for her to believe in.
So she began in the farm.
Each torus was octagonal, made of eight American shuttle fuel canisters that had been boosted into orbit and coupled together. More bundled canisters formed the long axis that speared down the centers of the torus octagons, and the octagons were connected to the central axis by narrow spokelike passage tubes. The entire spacecraft spun on the long axis as it moved forward toward Mars, spinning at a speed that created a centrifugal force the equivalent of Martian gravity, at least for people walking on the floors set against the outside of the torus rings. The Coriolis force meant that if you walked against the rotation of the ship you felt you were leaning forward a little. The opposite effect, walking in the other direction, was somehow not so noticeable. You had to lean into reality to make progress.