Elliptical Orbits Lunar Orbit Asteroid Orbits Perigee Lunar Phases Moon Orbit Gravity Moon Phases Satellite Technology Moon's Orbit Space Debris Trajectory Celestial Dynamics Gravitational Effects Trajectory Calculations Trajectory Analysis Impact Probability Trajectory Optimization Trajectory Predictions Spacecraft Dynamics Asteroid Characteristics Satellite Tracking Space Environment Space Missions Satellite Dynamics Comet Orbits Binary Asteroids Cometary Orbits