[johndallman]

Astronomy: Knowledge about everything from asteroids to galaxies, and the ability to use instruments to observe them and use mathematics and physics to form theories about them and make calculations and predictions based on those theories. It has a prerequisite of Mathematics (Applied). The boundary between Astronomy and Physics (Astrophysics) is not well-defined, but it isn't in the real world. Astronomy gives defaults in many kinds of Navigation.

There's no astronomical equipment in High-Tech or Ultra-Tech, but Low-Tech has some, PLUS material about using Astronomy for practical purposes, and there's a lot more in Low-Tech Companion 1. Fantasy-Tech says a good clock gives +2 to Astronomy. There is, naturally astronomical material in Space. Magic has Astrology as a form of the Divination spell, which requires Astronomy at 15+.

Some other hard skills probably have equivalents of Astronomy (Observational), for people who've studied it as a hobby, but lack the tools to do the productive-but-hard tasks. However, I haven't found any examples yet: the ones I create keep turning out to be hobbyists' lack of Research skill. Any suggestions?

Astronomy has been quite important in my Infinite Cabal campaign, for finding out the astronomical date of worlds. This started when the Royal Society was looking for a relationship between the rate of flow of time in worlds and their current date, but it became clear that if there's a relationship, it is complex. The discovery that one world was at about 250CE, on cultural and historical evidence, but around 1700CE by the planets, led to one of those chains of events where the players become sufficiently disturbed that they decide by themselves that the characters should be making fright checks.

What have you done with Astronomy in games? The most obvious uses are in space exploration games, and trying to justify claims that the Stars are (or aren't) Right, but other uses surely exist.