what is moon elongation to sun
(glossary entry). The elongation of the Moon is the apparent angular distance of the center of the Moon from the center of the Sun as seen by a particular observer. - JimMosher.This page has been edited 5 times. The last modification was made by-JimMosher on Nov 25, 2008 12:20 pm-mgx2. The elongation angle is listed as the Sun-Observer-Target or SOT angle in the lunar output from JPL Horizons. 2  It is an approximate determinant of the theoretical percent illumination of the Moon, which is calculated as if the Moon were a perfect sphere (see: phase). - 3  JimMosher.