Cafodd y gwaith hwn ei ryddhau i'r parth cyhoeddus gan ei awdur, Tomruen. Mae hyn yn weithredol ledled y byd. Hwyrach nad yw hyn yn bosib yn ôl cyfraith rhai gwledydd; os felly: Mae Tomruen yn rhoi i unrhywun yr hawl i ddefnyddio'r gwaith hwn at unrhyw ddiben, heb unrhyw amodau, oddieithr unrhyw amodau gofynnol yn ôl y gyfraith.

{original upload log}

This image is a derivative work of the following images:

• File:Lunar_libration_with_phase_Oct_2007.gif licensed with PD-self
  • 2007-11-06T01:03:49Z Tomruen 640x642 (10111965 Bytes) 'Summary == Information | Description = {en|[Moon|Lunar][en:libration..for more descriptions'

[:fr:Libration|[:fr:lune|lune]. description'

Uploaded with derivativeFX

Technical

• Book: "Astronomical Formulae for Calculators, 4th edition", Jean Meeus, 1988, published by "Willmann-Bell, Inc"
  • Chapter 30 "Position of the Moon"

Source bitmap for projection from NRL's Clementine Spacecraft:

• USGS: Global simple cylindrical projection at 10 km/pixel. [1]

• Animation
  • 60 frames, 12 hour step.
  • Period used: 29.5 days
  • Animation began and ended near Apogee to minimize "jumping" when cycles back to the start.
  • New moon given an unreal 1% intensity "Ambient light" to show motion in all phases.
  • View assumed from the center of the earth. (Geometrically impossible, but best demonstration of monthly libration caused by moon's motion versus the shorter daily libration that would be included from the surface of the earth.)

This version of the animation has less frames compared to the original to make the loop continuous (jumpiness when restarting).