Caption: Prograde motion (i.e., same direction) and retrograde motion (i.e., opposite direction) relative to the axial rotation of the primary.
The primary is an Earth-analog planet which has a planet-moon system.
The orange moon orbits in a retrograde motion. The other moons have prograde motions.
Credit/Permission: ©
User:Silver Spoon,
2012 /
Creative Commons
CC BY-SA 3.0.
Animation link:
Wikimedia Commons.
Local file: local link: prograde_retrograde.html.
File: Orbit file:
prograde_retrograde.html.