Astronomy

The Moon’s hidden edges

Increase orbital eccentricity and follow the difference between uniform rotation and nonuniform orbital motion. Surface markers reveal the rocking.

Actual application image

The model and its limits

Keplerian orbit with uniform synchronous spin; latitude libration is a prescribed axial tilt. Physical libration and solar perturbations are omitted.

Equations used in the module

Equations
E - e sin E = M; tan(ν/2) = √((1+e)/(1-e)) tan(E/2); libration = ν - M

Astronomy / Earth

Trace the Sun at the same mean solar time throughout a year. Remove tilt or eccentricity to discover the two sources of the figure eight.

Astronomy

Move a planet through the stellar radiation field. Compare absorbed and emitted energy as stellar luminosity and cloud reflectivity change.

Astronomy / Earth

Probe a calculated rocky planet, or explore reference cutaways of the Sun and the four giant planets.