The greatest angular distance that the Sun can be from the nodes of the Moon's orbit and still cause an eclipse. The actual value varies with the changing distances, and hence apparent sizes, of the Sun and Moon. Maximum values (the major ecliptic limits) are attained when the Earth is at perihelion and the Moon is at perigee, while minimum values (the minor ecliptic limits) occur at aphelion and apogee. For a partial solar eclipse, the solar ecliptic limit (i.e. the greatest possible distance of the Sun from the node of the Moon's orbit at new Moon) has a maximum value of 18°.4; for a total solar eclipse it is 11°.8. For a partial lunar eclipse, the lunar ecliptic limit (i.e. greatest possible distance of the Sun from the Moon's node at full Moon) has a maximum value of 12°.2; for a total lunar eclipse, it is 5°.9.
Subjects: Astronomy and Astrophysics.