Gravitational perturbation

A change in an object's motion caused by gravitational forces beyond its main attracting body. Such influences alter its orbit or trajectory over time.

N-body problem: The problem of predicting the motion of multiple bodies interacting through gravity. Perturbations arise when orbital motion departs from the idealized two-body problem.
Celestial mechanics: The study of the motions of celestial bodies under gravity. It provides the mathematical framework for analyzing gravitational changes to orbits.
Neptune's discovery: The 1846 identification of Neptune after astronomers predicted its position from irregularities in Uranus's orbit. Uranus's unexplained motion was attributed to the gravitational pull of an unseen planet.
Keplerian orbit: An ideal orbit in which two bodies move under their mutual gravity alone. It is the unperturbed reference path from which gravitational deviations are measured.
Perturbation theory: A family of methods that approximate a difficult problem by adding small corrections to a solvable one. Orbital calculations often treat secondary gravitational forces as corrections to a dominant attraction.
Orbit determination: The estimation of an object's orbital state from observations and a dynamical model. Observed perturbations help refine an object's position, velocity, and orbit.
Pluto: A dwarf planet in the Kuiper belt whose orbit crosses inside Neptune's orbital distance. Neptune's perturbations help maintain Pluto's resonant orbit and protect it from close encounters.
Two-body problem: The exactly solvable model of two bodies interacting only through their mutual gravitational attraction. Perturbations arise when real systems include influences excluded from this idealization.
Orbital resonance: A condition in which orbiting bodies have periods related by a ratio of small whole numbers. Repeated gravitational tugs can accumulate when orbital periods form a resonance.
Spacecraft trajectory optimization: The design of spacecraft paths to meet mission goals while minimizing costs such as fuel or travel time. Mission designers exploit and account for gravitational changes along spacecraft trajectories.

Linked from 15 pages