It must have looked strange, Jays thought, if there had been anyone around to see it. The Rover looked like a beach buggy from somebody’s home workshop. And yet here were the two of them in their shining white pressure suits, like two dough boys riding a construction-kit car, bouncing across the Moon itself. They rose up a slight incline.

Suddenly there was the rille: Schröter’s Valley, a gap in the landscape in front of them. It wound into the distance, its walls curving smoothly through shadows and sunlight. Jays could see boulders that must have been the size of apartment blocks, strewn over its floor.

Jays tried to keep the excitement out of his voice. “Look at that old rille. I’m sure I can see layering in the far side. Look, Tom. Over at one o’clock.”

Tom, distracted by the driving, said, “Let’s get up there before we do any geology.”

The Rover jolted to a stop.

Jays released his seat belt, and let it snap back into its frame. He tried to stand up. But the slope was deceptive; it was an effort to haul his suited frame out of the Rover’s lawn seat.

He took a step away from the Rover.

His suit was a stiff bubble around him, shutting out the Moon. He could hear the whir of pumps and fans in his backpack, feel the reassuring breath of oxygen over his face. The sunlight caught scuffs and scratches in his gold-tinted sun visor, creating star-bursts.

He looked up, towards the south, and there was the Earth, hanging in the sky like a blue thumb-nail. He could see a depression over the South Atlantic, a fat white swirl. Other than the Earth and the big white spotlight that was the sun, the sky was empty: save only for a single bright star that tracked across the zenith every couple of hours. That was the Apollo Command Module, waiting in orbit to take them home.