The four basics “scales” at which astronomy is studied, that of (1) the Earth-Moon system, (2) the solar system, (3) the galaxy, and (4) the universe (Fig. 1), are a common place to start an intro astronomy course. In fact, courses and textbooks are often divided into approximately four sections based on these scales.

See “Supplemental” tab at TPT Online at for Appendices 1 and 2.

Supplementary Material

AAPT members receive access to The Physics Teacher and the American Journal of Physics as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.