But there is, lurking within The Moon of Gomrath, the idea that something else is going to happen.
Possibly most of the features were formed when temperatures within the moon were changing rapidly during its first few million years of existence.
NASA's scientists have just announced that two asteroids are going to swish by today, within the moon's distance of Earth.
Titan always has the same face toward Saturn, and the planet's strong gravitational pull causes solid tides within the moon, adding to the deformation.
For the icy crust to vary in thickness across Titan's surface, the heat distribution within the moon must vary as well.
The field is thought to have been generated by the churning movement of fluids within the moon's molten core – a sort of lunar dynamo.
While the larger pieces remain within the moon's orbit and eventually are swept up by the moon, smaller particles are subject to subtle forces that push them toward or away from the planet out of the moon's orbit.
Although Garner had previously said, back in 1989, that a third book was "lurking within" The Moon of Gomrath, at the time he was sure it would never happen.
"The variation in the shape of the orbit, along with Titan's slightly distorted shape, means that there is some flexure within the moon as it orbits Saturn," said Zebker.
That favors a model in which much of Io's heat rises from deep within the moon and emerges near the poles, rather than spreading uniformly from shallower reservoirs of magma.
Unusual minerals spotted in some lunar craters may not have come from deep within the moon: They may be remnants of the objects that blasted the craters in the first place, a new study suggests.
