Ice is a native resource of frozen volatiles, mined from bodies rather than made. It is found from the Static outward and is richest by far in the Fade. It is the source of Water and of everything made from water.
Formation
Ice condenses only beyond a star's frost line, where starlight alone keeps it below its sublimation point, so it gathers in the outer part of a system. A hotter star pushes the frost line further out.
Ice is bright. A surface of it reflects most of its star's light, so an icy body runs colder than a dark one at the same distance.
Behaviour
What happens to ice depends on its body's gravity:
- On a body with a gravity below 500, ice warmer than 150 K sublimates straight into the body's Trail. This is a comet's tail.
- A body with a gravity of 500 or more holds its vapour instead. Above 273 K its ice melts into water, which freezes back when it cools.
Uses
A Smelter melts ice into water, the first step toward hydrogen, oxygen and fuel.