Astrophysics (index) | about |

Elliptical,
1 being parabolic, and greater than
1 being hyperbolic.
The eccentricity of an elliptical orbit is:
Where *e*is the eccentricity*r*is the radius at_{a}**apoapsis**(furthest distance)*r*is the radius at_{p}**periapsis**(closest distance)
Earth's orbit has an eccentricity of 0.0167. The Moon's is 0.0549. Halley's Comet's is 0.97. Eccentricity can aid in the study of Atmospheres of Extra-Solar Planets, i.e., bodies orbiting stars, because the changes in EM Radiation from the host star allow observation of the atmosphere at multiple Temperatures using Light Curve Spectroscopic observations. orbits,celestial mechanics,measure)Referenced by:
Apsis DQ Tau EXOSAT HD 80606 b Hill Radius Kozai Mechanism Kuiper Belt (K Belt) Late Heavy Bombardment (LHB) Libration Mercury Moon Orbital Element Planet Nine Planet Formation Precession Laplace Radius (r _{L})
Semi-Major Axis ( a)
Solar Circle Solar Time Synchronous Orbit Synodic Period Tidal Heating |