An Introduction to Modern Astrophysics · Problem 20.19

The Formation of Planetary Systems — Carroll & Ostlie

Physics — Astrophysics · mars-moons-apparent-motion

Problem

Suppose you lived on Mars and watched its moons. If Phobos and Deimos were next to each other one night, what would you see the next night (one Martian day later)? Describe the apparent motions of the two moons. (Both Phobos and Deimos orbit prograde, approximately above the planet's equator.)

Related theory

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