The longest lunar eclipse in centuries will happen this week.

The “nearly total” lunar eclipse is expected overnight Thursday, Nov. 18, to Friday, Nov. 19. The eclipse will last 3 hours, 28 minutes and 23 seconds, making it the longest in centuries.

For U.S. East Coast observers, the partial eclipse begins a little after 2 a.m., reaching its maximum at 4 in the morning, for observers on the West Coast, that translates to beginning just after 11 p.m., with a maximum at 1 a.m.