Planets¶

Draft

This page is scaffolded. The outline below marks what it should cover.

A Planet (and the Earth preset) is a world-level entity that ties a planet-fixed frame to the shared fields.

To cover¶

The planet-fixed frame — axis + rotation rate, and the symbolic + numpy transforms between PlanetFrame and WorldFrame.
Standing disturbances — what Earth auto-registers on the world's shared fields: point-mass (+ optional J2) gravity, ocean + ISA atmosphere via PlanetFrameFluid, a dipole magnetic field.
Initial-state factories — earth.position(...), earth.velocity(...), earth.at_rest() and how they resolve to WorldFrame seeds at compile time.
Multiple planets in one world, superposing into the shared fields.
Earth's rotation and the gyrocompass — sensing Earth-rate (see the gyrocompass demo).