What is retrograde motion?

Answer by  dee68 (244)

Retrograde motion is the illusion of a celestial body or mass (usually a planet or moon) traveling in an opposing direction then the rest of its neighboring bodys or masses.

Answer by  Matthew93 (26)

Retrograde motion is defined as motion opposite to something else. For example, a retrograde orbit around a planet is an orbit moving opposite the rotation of the planet beneath the orbit -- this means that if the planet were rotating clockwise, a retrograde orbit would be a counter-clockwise orbit.