But strangest of all are the lights, fierce as tiny suns, that can often be observed moving across the darkness between these other worlds. Once, recalling the bioluminescence of their own seas, some Europans had speculated that these might indeed be living creatures; but their intensity makes that almost incredible. Nevertheless, more and more thinkers believe that these lights – the fixed patterns, and moving suns – must be some strange manifestation of life.
Against this, however, there is one very potent argument. If they are living things, why do they never come to Europa?
Yet there are legends. Thousands of generations ago, soon after the conquest of the land, it is said that some of those lights came very close indeed – but they always exploded in sky-filling blasts that far outshone the Sun. And strange, hard metals rained down upon the land; some of them are still worshipped to this day.
None is as holy, though, as the huge, black monolith that stands on the frontier of eternal day, one side forever turned to the unmoving Sun, the other facing into the land of night. Ten times the height of the tallest Europan – even when he raises his tendrils to the fullest extent – it is the very symbol of mystery and unattainability. For it has never been touched; it can only be worshipped from afar. Around it lies the Circle of Power, which repels all who try to approach.
It is that same power, many believe, that keeps at bay those moving lights in the sky. If it ever fails, they will descend upon the virgin continents and shrinking seas of Europa, and their purpose will be revealed at last.
The Europans would be surprised to know with what intensity and baffled wonder that black monolith is also studied by the minds behind those moving lights. For centuries now their automatic probes have made a cautious descent from orbit – always with the same disastrous result. For until the time is ripe, the monolith will permit no contact.
When that time comes – when, perhaps, the Europans have invented radio and discovered the messages continually bombarding them from so close at hand – the monolith may change its strategy. It may – or it may not – choose to release the entities who slumber within it, so that they can bridge the gulf between the Europans and the race to which they once held allegiance.
And it may be that no such bridge is possible, and that two such alien forms of consciousness can never coexist. If this is so, then only one of them can inherit the Solar System.
Which it will be, not even the Gods know – yet.
Acknowledgements
My first thanks, of course, must go to Stanley Kubrick, who a rather long time ago wrote to ask if I had any ideas for the 'proverbial good science-fiction movie'.
Next, my appreciation to my friend and agent (the two are not always synonymous) Scott Meredith, for perceiving that a ten-page movie outline I sent him as an intellectual exercise had rather wider possibilities, and that I owed it to posterity, etc., etc.
Other thanks are due to:
Señor Jorge Luiz Calife of Rio de Janeiro, for a letter which started me thinking seriously about a possible sequel (after I'd said for years that one was clearly impossible).
Dr Bruce Murray, past Director of the Jet Propulsion Laboratory, Pasadena, and Dr Frank Jordan, also of JPL, for computing the Lagrange-1 position in the Io-Jupiter system. Oddly enough, I had made identical calculations thirty-four years earlier for the colinear Earth-Moon Lagrange points ('Stationary Orbits', Journal of the British Astronomical Association, December 1947) but I no longer trust my ability to solve quintic equations, even with the help of HAL, Jr., my trusty H/P 91OOA.
New American Library and Hutchinson & Co., publishers of 2001: A Space Odyssey, for permission to use the material in Chapter 51 (Chapter 37 of 2001: A Space Odyssey) and also quotations in Chapters 30 and 40.
General Potter, US Army Corps of Engineers, for finding time in his busy schedule to show me around EPCOT in 1969 – when it was only a few large holes in the ground.
Wendell Solomons, for help with Russian (and Russlish).
Jean-Michel Jarre, Vangelis, and the incomparable John Williams, for inspiration whenever it was needed.
C. P. Cavafy for 'Waiting for the Barbarians'.
While writing this book, I discovered that the concept of refuelling on Europa had been discussed in a paper, 'Outer planet satellite return missions using in situ propellant production', by Ash, Stancati, Niehoff, and Cuda (Acta Astronautica VIII, 5-6, May-June 1981).
The idea of automatically exponentiating systems (von Neumann machines) for extraterrestrial mining has been seriously developed by von Tiesenhausen and Darbro at NASA's Marshall Space Flight Center (see 'Self-Replicating Systems' – NASA Technical Memorandum 78304). If anyone doubts the power of such systems to cope with Jupiter, I refer them to the study showing how self-replicating factories could cut production time for a solar power collector from 60,000 years to a mere twenty.
The startling idea that gas giants might have diamond cores has been seriously put forward by M. Ross and F. Ree of the Lawrence Livermore Laboratory, University of California, for the cases of Uranus and Neptune. It seems to me that anything they can do, Jupiter could do better. De Beers shareholders, please note.
For more details on the aerial life forms that might exist in the Jovian atmosphere, see my story 'A Meeting With Medusa' (in The Wind From the Sun). Such creatures have been beautifully depicted by Adolf Schaller in Part 2 of Carl Sagan's Cosmos ('One Voice in the Cosmic Fugue'), both book and TV series.
The fascinating idea that there might be life on Europa, beneath ice-covered oceans kept liquid by the same Jovian tidal forces that heat Io, was first proposed by Richard C. Hoagland in the magazine Star and Sky ('The Europa Enigma', January 1980). This quite brilliant concept has been taken seriously by a number of astronomers (notably NASA's Institute of Space Studies' Dr Robert Jastrow), and may provide one of the best motives for the projected GALILEO Mission.
And finally: Valerie and Hector, for providing the life-support system; Cherene, for punctuating every chapter with sticky kisses; Steve, for being here.
COLOMBO, SRI LANKA JULY 1981-MARCH 1982
This book was written on an Archives III microcomputer with Word Star software and sent from Colombo to New York on one five-inch diskette. Last-minute corrections were transmitted through the Padukka Earth Station and the Indian Ocean Intelsat V.