A Fall of Moondust - By Arthur C. Clarke

Chapter 1
To be the skipper of the only boat on the Moon was a distinction that Pat Harris enjoyed. As the passengers filed aboard Selene, jockeying for window seats, he wondered what sort of trip it would be this time. In the rear-view mirror he could see Miss Wilkins, very smart in her blue Lunar Tourist Commission uniform, putting on her usual welcome act. He always tried to think of her as "Miss Wilkins," not Sue, when they were on duty together; it helped to keep his mind on business. But what she thought of him, he had never really discovered.

There were no familiar faces; this was a new bunch, eager for their first cruise. Most of the passengers were typical tourists - elderly people, visiting a world that had been the very symbol of inaccessibility when they were young. There were only four or five passengers on the low side of thirty, and they were probably technical personnel on vacation from one of the lunar bases. It was a fairly good working rule, Pat had discovered, that all the old people came from Earth, while the youngsters were residents of the Moon.

But to all of them, the Sea of Thirst was a novelty. Beyond Selene's observation windows, its gray, dusty surface marched onward unbroken until it reached the stars. Above it hung the waning crescent Earth, poised forever in the sky from which it had not moved in a billion years. The brilliant, blue-green light of the mother world flooded this strange land with a cold radiance - and cold it was indeed, perhaps three hundred below zero on the exposed surface.

No one could have told, merely by looking at it, whether the Sea was liquid or solid. It was completely flat and featureless, quite free from the myriad cracks and fissures that scarred all the rest of this barren world. Not a single hillock, boulder, or pebble broke its monotonous uniformity. No sea on Earth - no millpond, even - was ever as calm as this.

It was a sea of dust, not of water, and therefore it was alien to all the experience of men; therefore, also, it fascinated and attracted them. Fine as talcum powder, drier in this vacuum than the parched sands of the Sahara, it flowed as easily and effortlessly as any liquid. A heavy object dropped into it would disappear instantly, without a splash, leaving no scar to mark its passage. Nothing could move upon its treacherous surface except the small, two-man dust-skis - and Selene herself, an improbable combination of sledge and bus, not unlike the Sno-cats that had opened up the Antarctic a lifetime ago.

Selene's official designation was Dust-Cruiser, Mark I, though to the best of Pat's knowledge, a Mark II did not exist even on the drawing board. She was called "ship," "boat," or "moon bus," according to taste; Pat preferred "boat," for it prevented confusion. When he used that word, no one would mistake him for the skipper of a spaceship - and spaceship captains were, of course, two a penny.

"Welcome aboard Selene," said Miss Wilkins, when everyone had settled down. "Captain Hams and I are pleased to have you with us. Our trip will last four hours, and our first objective will be Crater Lake, a hundred kilometers east of here, in the Mountains of Inaccessibility

Pat scarcely heard the familiar introduction; he was busy with his count-down. Selene was virtually a grounded spaceship; she had to be, since she was traveling in a vacuum, and must protect her frail cargo from the hostile world beyond her walls. Though she never left the surface of the Moon, and was propelled by electric motors instead of rockets, she carried all the basic equipment of a full-fledged ship of space-and all of it had to be checked before departure.

Oxygen - O. K. Power - O. K. Radio - O. K. ("Hello, Rainbow Base, Selene testing. Are you receiving my beacon?") Inertial navigator - zeroed. Air-lock safety - On. Cabin-leak detector - O. K. Internal lights - O. K. Gangway - disconnected. And so on for more than fifty items, every one of which would automatically call attention to itself in case of trouble. But Pat Harris, like all spacemen hankering after old age, never relied on autowamings if he could carry out the check himself.

At last he was ready. The almost silent motors started to spin, but the blades were still feathered, and Selene barely quivered at her moorings. Then