October 1986 lunar eclipse

Metonic series

This eclipse is the third of four Metonic cycle lunar eclipses on the same date, October 17–18, each separated by 19 years:

The Metonic cycle repeats nearly exactly every 19 years and represents a Saros cycle plus one lunar year. Because it occurs on the same calendar date, the Earth's shadow will in nearly the same location relative to the background stars.