equatorial region of Titan abounded in what, for want of a better phrase, might be called cold volcanoes.
On rare occasions, indeed, some of them actually erupted liquid water.
This activity, triggered by radioactive heat generated deep in the core of Titan, spewed megatons of
hydrogen compounds into the atmosphere, and so continually made up for the leakage into space. One
day, of course, the buried reserves — like the lost oil fields of Earth — would all be gone, but the
geologists had calculated that Titan could hold the vacuum of space at bay for at least two billion years.
Man's most vigorous atmospheric mining activities would have only a negligible influence on this figure.
Like the Earth, Titan has distinct seasons — though it is difficult to apply the word “summer” where
the temperature at high noon seldom climbs to fifty below. And as Saturn takes almost thirty years to
circle the sun, each of the Titanian seasons is more than seven Terran years in length.
The tiny sun, taking eight days to cross the sky, is seldom visible through the cloud cover, and there is very little temperature difference between day and night — or, for that matter, between Poles and
Equator. Titan thus lacks climate; but it can, on occasion, produce its own quite spectacular brand of weather.
The most impressive meteorological phenomenon is the so-called Methane Monsoon, which often —
though not invariably — occurs with the onset of spring in the northern hemisphere. During the long
winter, some of the methane in the atmosphere condenses in local cold spots and forms shallow lakes, up to a thousand kilometers square but seldom more than a few meters deep, and often covered with
fantastically shaped bergs and floes of ammonia ice. However, it requires the exceedingly low
temperature of minus a hundred and sixty to keep methane liquefied, and no part of Titan is ever that cold for very long.
A “warm” wind, or a break in the clouds — and the methane lakes will flash suddenly into vapor. It
is as if, on Earth, one of the oceans were to evaporate, abruptly increasing its volume hundreds of times and so completely changing the state of the atmosphere. The result would be catastrophic, and on Titan it is sometimes scarcely less so. Wind speeds of up to five hundred kilometers an hour have been recorded
— or to be accurate, estimated from their aftereffects. They last only for a few minutes; but that is quite long enough. Several of the early expeditions were annihilated by the monsoon, before it became possible to predict its onset.
Before the first landings on Titan, at the beginning of the twenty-first century, some optimistic
exobiologists had hoped to find life around the relatively warm oases that were known to exist. This hope was slow to fade, and for a while it was revived by the discovery of the strange wax formations of the famous Crystal Caves. But by the end of the century, it was quite certain that no indigenous life forms had ever existed on Titan.
There had never been any expectation of finding life on the other moons, where conditions were far
more hostile. Only Iapetus and Rhea, less than half the size of Titan, had even a trace of atmosphere. The remaining satellites were barren aggregates of rock, overgrown snowballs, or mixtures of both. By the
mid-2200's, more than forty had been discovered, the majority of them less than a hundred kilometers in diameter. The outer ones — twenty million kilometers from Saturn — all moved in retrograde orbits and
were clearly temporary visitors from the asteroid belt; there was much argument as to whether they should be counted as genuine satellites at all. Though some had been explored by geologists, many had never
been examined, except by robot space probes, but there was no reason to suppose that they held any great surprises.
Perhaps one day, when Titan was prosperous and getting a little dull, future generations would take up the challenge of these tiny worlds. Some optimists had talked of turning the carbon-rich snowballs into orbital zoos, basking beneath the warmth of their own fusion suns and teeming with strange life forms.
Others had dreamed of private pleasure domes and low-gravity resorts, and islands in space for
experiments in super-technology life styles. But these were fantasies of a Utopian future; Titan needed all its energies now to solve its coming crisis, in this demimillennial year of 2276.
5
The Politics of Time And Space
When only two Makenzies were talking together, their conversation was even more terse and
telegraphic than when all three were present. Intuition, parallel thought processes, and shared experience filled in gaps that would have made much of their discourse wholly unintelligible to outsiders.
"Handle?" asked Malcolm.
"We?!" retorted Colin.
"Thirty-one? Boy!"
Which might be translated into plain English as:
"Do you think he can handle the job?"
"Have you any doubts that we could?"
"At thirty-one? I'm not so sure. He's only a boy."