Bay Area residents will have an orchestra-seat view of a rare astronomical event this Saturday: a total lunar eclipse.
A lunar eclipse happens when the Earth and sun align so that the Earth casts a shadow on the moon.
This can occur up to three times a year. But Saturday morning’s show will be a total eclipse, when the moon is full and the Earth’s shadow completely covers it.
This happens twice annually at most, and can only be seen from whichever hemisphere is shrouded in darkness at night.
On Saturday, it will be visible from Western North America, though the total part of the eclipse–when the moon is in the sun’s full shadow–will only be visible for a fleeting five minutes, between 4:58-5:03 a.m.