|
17 December 2008 23:22
- perigee is the point in an object's orbit around the earth where it is closest to the earth
- contrast with apogee, which is the point where the object is farthest from the earth
- should only apply to objects, such as the moon, which have elliptical orbits
- the more elliptical the orbit, the greater the difference in distance at perigee and apogee
- the "eccentricity" of an orbit is the degree to which the orbit is elliptical
- periapsis or apoapsis are the corresponding terms for generic objects, for objects circling the sun, the terms are perihelion and aphelion
- we just (on 12/12/2008) experienced a full moon (more or less) at perigee - the closest full moon in 15 years - an excellent image and comparison to an apogee full moon is here
- another full moon will occur within 16 hours of perigee on 1/10/2009, but the closest full moon of 2009 is on 7/7
- an online lunar perigee/apogee calculator is here
|
Orion Telescopes
|