Planets

07: Planets

Status: planned. This module is scoped but not yet written. The scope below is the commitment; it is here so you can see where the curriculum is going and tell us if the plan is wrong.

Where the planets are, why they sometimes appear to move backwards, and how to find them tonight.

Planned lessons

• Finding a planet tonight, altitude, azimuth, and whether it is even up
• Elongation and why Venus is never far from the Sun
• Retrograde motion, built from two circular orbits
• Conjunctions and oppositions, and predicting the next one
• Synodic periods, the same arithmetic as module 02

Prerequisites

• Module 02 (synodic periods)
• Module 05 (local sky)

Intended approach

src/moonfield/planets.py, using VSOP87 truncated series in the same style as moon.py.

Want this sooner?

Say so in Discussions, demand genuinely reorders the queue. Better still, write a lesson: see CONTRIBUTING.md. A single lesson following the lab pattern is a complete, useful contribution.

If you want to work through this material now without waiting, say so in Discussions and someone will point you at good sources. The reading list is not the bottleneck; the lab-shaped version is.