| The equinoctial colure is a great circle which passes through the celestial poles and the ecliptic at the two equinoxes. |
| If the Sun is close to one of the nodes when the Moon crosses the ecliptic, an eclipse is imminent. |
| Another eight years later the node has moved beyond the ecliptic limit, and no transit can take place. |
| The nodical period is the period between two crossings of the ecliptic in the same direction. |
| Abul Wafa determined accurately the obliquity of the ecliptic in 995 A.D. and calculated the variation in the moon's motion. |
| We get a partial solar eclipse when the Moon's path almost intersects the ecliptic. |
