A Fall of Moondust is a 1961 Science Fiction novel by Arthur C. Clarke. Set sometime in the 21st century, the story takes place in and around the Sea of Thirst, a fictional region of The Moon bearing a sea of incredibly fine moondust that behaves like water, upon which "buoyant" objects can float. The Lunar tourism authority operates the dust-cruiser Selene, a vessel which rides atop the surface like a boat and takes passengers on sightseeing tours across the Sea of Thirst.
When an ill-timed moonquake creates a disturbance that swallows Selene beneath the surface and cuts the dust-cruiser off from outside communication, the routine trip becomes a race to stay alive long enough to be rescued, and indeed for those above the surface to even discover that a rescue is needed. Coordinating the effort to survive and stay sane are Selene captain Pat Harris and flight attendant Sue Wilkins; aided by the vessel's diverse passengers, including retired legendary astronaut Commodore Hansteen. The search and rescue effort from above is headed by Lunar Chief Engineer Robert Lawrence and prickly astronomer Dr. Thomas Lawson, who are faced with a ticking clock, their own disdain for each other, and every nasty surprise the Sea of Thirst has left to throw at them.
The book was nominated for a Hugo Award for Best Novel in 1963.
A Fall of Moondust contains examples of:
- Absent Aliens: Astronauts have myths of "Outsiders," an idea born of long isolation in alien environments. They aren't implied to actually exist.
- Afraid of Needles: Although the sleep aids aboard Selene are more advanced and less painful than a regular needle, one passenger outright refuses the shot, initially claiming religious reasons. The truth is promptly revealed that he's freshly recovering from a drug addiction and has been psychologically conditioned against being injected with anything.
- Almost Out of Oxygen: On paper, Selene has a few days' worth of usable air; however, the pent-up heat produced by the ship and passengers, unable to radiate away underneath fifteen meters of moondust, causes the onboard air purifier to fail, creating a soon-to-be-deadly carbon dioxide buildup despite plenty of remaining oxygen. A fresh air supply piped down from the surface only reaches Selene in time thanks to the cruiser's stock of injectable sleep aids keeping almost everyone unconscious. By the time the air pipe cuts through the inner hull, Harris is so loopy from CO2 poisoning that he nearly scuttles the attempt by opening the supply valve too early while the pipe's other end is still in vacuum.
- Colonized Solar System: The Moon is developed enough to have its own bureau for tourism, and humans such as Hansteen have ventured to the very outer worlds. The largest settlement on the Moon has a population of just over 50,000.
- Cool Boat: Selene manages to merge this with Cool Starship, although the former fits more closely given its uniqueness as a "boat."
- Courtroom Antics: To entertain themselves, the passengers stage a mock courtroom where people are randomly selected to be "cross-examined" about the reason for their trip to the Moon. The "court" does tap into the Hidden Depths of several characters, but is essentially in good fun.
- Distant Finale: The final chapter takes place one year after the rescue, featuring Harris setting out on his last tour as captain of the successor vessel Selene II before transferring to the Space Service.
- Fight to Survive: The task of those aboard Selene is buying enough time for the rescue party to dig them out, with the ingenuity of the rescuers pitted against the clock.
- Getting Hot in Here: As the temperature inside Selene starts to rapidly climb, Harris and Hansteen advise the passengers to remove unnecessary clothing (though they don't initially let on that the heat is a serious danger, to avoid panic). Everyone aboard remains in a state of partial undress throughout the rest of the ordeal.
- Hidden Depths: We learn a great deal about the passengers trapped aboard Selene over the course of the story.
- Human-Interest Story: Maurice Spenser is highly motivated to make his news network the first to report on developments surrounding the Selene disaster.
- Instant Sedation: The sleep aid injectors used to render the passengers unconscious appear to work pretty much instantaneously.
- Insufferable Genius: Dr. Lawson, whose misanthropy and lack of patience for others are implied to stem from a lonely childhood at a Dickens-esque orphanage. Until it burned down.
- Intrepid Reporter: Senior Interplanet News journalist Maurice Spenser hires a freighter to land atop the mountain range at the center of the Sea of Thirst, all to get a close enough look at the rescue operation as it happens.
- Locked in a Freezer: The temperature-inverse variety. Selene is buried under fifteen meters of dust with an unusable radio, a rapidly dwindling air supply, and no way to dump waste heat.
- Manly Tears: Safe at last, Harris can no longer help himself when he feels Selene explode beneath him.Harris: Good old bus - she lasted just long enough.
- No Antagonist: Only the Moon's natural environment.
- Outrun the Fireball: Moments after Harris, the last person aboard, climbs free of the escape tunnel to safety, the fire that had started in the washroom reaches the liquid oxygen tanks, and there's a shudder and a blast of smoke from the tunnel signaling the explosive collapse of Selene.
- Quicksand Sucks: While it isn't quite sand, the lunar dust upon which Selene sails has the same effect when the dust-cruiser is sucked beneath the surface. Averted, however, when Lawrence falls off a dust-ski into the Sea of Thirst during the search effort; he initially panics, before discovering that he's nowhere near dense enough to sink in his pressurized space suit.
- The Radio Dies First: Selene is cut off from radio contact by the thick dust above as soon as it sinks. Hearing nothing from the craft, ground controllers and Lunar administration initially assume it was crushed by a rockslide.
- Reports of My Death Were Greatly Exaggerated: At first, everybody on the surface is certain the crew and passengers are already dead. It takes the persistence of Dr. Lawson (who's motivated in the attempt more by curiosity over whether his detection system works properly than any belief that Selene is still intact) for them to realize there's still people to save.
- Retired Badass: Commodore Hansteen, veteran astronaut. His fame is such that he boards Selene under a pseudonym to avoid attracting attention. He coolly steps up to aid Harris and Wilkins in marshaling the passengers, and is a natural leader of high enough caliber that he has to rein himself in to avoid subverting Harris's authority.
- Sand Is Water: The incredibly fine moondust that makes up the Sea of Thirst is a comparable example, and even flows similarly to water in the Lunar environment. Both Selene and the Lunar engineers' smaller dust-skis "float" and propel themselves across the surface like watercraft.
- Sinking Ship Scenario: Systems are starting to fail on Selene because of the dust crushing the already-sunken craft. At one point, it sinks even deeper.
- Smart People Wear Glasses: Eyeglasses have chiefly fallen out of use, but remain a cultural hallmark of doctors and lawyers. Attorney-at-law Irving Schuster sports a pair.
- Stellar Name: Selene is named for the Greek goddess of the Moon.
- Tourism-Derailing Event: A fear of Lunar administration in the wake of the apparent loss of Selene and its passengers. The epilogue implies tourism on the Moon is as alive as ever following the rescue, with passenger volume higher than before and Harris commanding the larger Selene II.
