Orbital motion

Science

Definition

Orbital motion occurs when an object moves in a curved path around another object due to gravitational attraction. The orbiting object is in continuous free fall, with its forward velocity balanced by the gravitational pull toward the central body. Orbits can be circular or elliptical.

Examples

  • The Moon orbiting Earth approximately every 27.3 days
  • The International Space Station orbiting Earth at about 28,000 km/h
  • Planets following elliptical orbits around the Sun as described by Kepler's laws
Key Fact

Orbital velocity: v = √(GM/r), where G is the gravitational constant, M is the central mass, and r is the orbital radius.

Related Terms

Universal gravitation Centripetal force Earth-moon system Solar system

Study This Concept

Practice orbital motion with free review games in these units:

Physics Unit 5: Circular Motion and Gravity