The clarity was incredible, though. When he peered down into the craters, especially when the shadows were long, he could see boulders, even broad scars in crater walls that had to be landslides. He could even see details by the milky blue of Earthlight; the landscape disappeared only when they flew through the double shadow of Earth and Moon. The view was so clear, in fact, that his vision kept playing tricks on him. The smoother craters seemed to reverse, popping up into domes or blisters, then sinking back to depressions. He couldn’t tell if he was sixty-nine miles up or six, and every so often, as some new mountain passed below, his heart would skip a beat, as if the Moon was clawing up into the sky.

Now the jokes by those old Apollo guys didn’t seem so funny. Sixty-nine miles high? Watch out for the seventy-mile mountain on the Moon’s backside…

He craned to see more. This module had been designed for survival, not as a viewing platform, and it was unbelievably frustrating to be so close and not to be able to see properly. Like driving through a national park, he thought, in a Sherman tank.

As he skimmed around the rocky limb, passing from shadow to light, he learned that shadows — the angle of the sun — were the key to seeing, on the Moon. When the sun rose, other features would become more prominent, like the brighter ray systems. They looked, he thought, like the marks left where a pickaxe had dug into concrete.

But when he was subsolar, with the sun behind him, the shadows were flattened, or disappeared altogether, as if he was looking down at the bleached floor of some dead ocean.

In fact, when the sun was right behind him, the lunar landscape seemed to brighten suddenly. Heiligenschein, the lunar scientists called it. The saint’s halo: some obscure effect of the dust.

But navigation using landmarks was going to be difficult, at high lunar noon. He conceded the wisdom of the old Apollo planners, who had sent all their guys in to land at lunar morning, when the low sun would send forward nice long crisp shadows for seeing…

While he analysed, Geena and Arkady were sightseeing.

“It’s colourless,” Geena said. “Basically shades of grey. Like plaster of paris, or maybe a deep, greyish builder’s sand.”

“Or pumice stone,” Arkady said. “Or a beach. Perhaps after a picnic. All churned up by a volleyball game, embers of the bonfire everywhere…”

“Bullshit,” said Henry, angrily. “Arkady, you spent too long on Cocoa Beach. This is why they made a mistake sending you guys, you aviators, in the first place, on Apollo. You tourists can’t even describe what you’re seeing.”

“What’s to describe?” Geena said grimly. “It’s just a ball of rock. Christ, it looks bleak. A huge expanse of nothing—”