A continuation of the LLR led to an improvement in accuracy of the lunar ephemeris
of three orders of magnitude, an improvement in the measurement of the variations of the Moon's rotation of several orders of magnitude, and the discovery of additional information regarding the Moon's tidal acceleration and rotational dissipation .
All the numerate officers had to assist in this task, even junior officers had to assist in the tedious manual computations required to determine the lunar ephemeris
. Cook was well aware of the deficiencies of each method he used and utilised a clever combination of techniques to offset the known problems of each.
When it comes to the lunar ephemeris
, the observer is most concerned with two values: illumination (the percentage of the disk that is sunlit) and libration (the limb that is tipped toward the Earth).
2100 begins at a given place even if we make use of a perfectly accurate lunar ephemeris