There were rocks and boulders scattered about, and ridges that might have been twenty feet high — but it was hard to judge distance because there were no plants, no buildings, no people to give him any sense of scale: it was more barren than the high desert of the Mojave, with not even the haze of an atmosphere, so that rocks at the horizon were just as sharp as those near his feet.

Muldoon was overwhelmed. The sims — even his previous spaceflight in Earth orbit on Gemini — hadn’t prepared him for the strangeness of this place, the jewel-like clarity about the airless view, with its sharp contrast between the darkness of the sky and the lunar plain beneath, jumbled with rocks and craters.

Holding the ladder with both hands, Muldoon swung his feet off the pad and onto the Moon.

It was like walking on snow.

There was a firm footing beneath a soft, resilient layer a few inches thick. Every time he took a step a little spray of dust particles sailed off along perfect parabolae, like tiny golf balls. He understood how this had implications for the geology: no atmospheric winnowing on the Moon, no gravitational sorting.

In some of the smaller zap craters he saw small, shining fragments, with a metallic sheen. Like bits of mercury on a bench. And here and there he saw transparent crystals lying on the surface, like fragments of glass. He wished he had a sample collector. He would have to remember to come back for these glass beads, during the documented sampling later.

His footprints were miraculously sharp, as if he’d placed his ridged overshoes in fine, damp sand. He took a photograph of one particularly well-defined print; it would persist there for millions of years, he realized, like the fossilized footprint of a dinosaur, to be eroded away only by the slow rain of micrometeorites, that echo of the titanic bombardments of the deep past.

Muldoon’s job was to check his balance and stability. He did turns and leaps like a dancer. The pull of this little world was so gentle that he couldn’t tell when he stood upright, and the inertia of the PLSS at his back was a disconcerting drag at his changes of motion.