The celestial curtains are rising tonight on a lunar extravaganza. Just walk outside now and look up.

The Earth is sliding directly between the moon and the sun, creating a total lunar eclipse. There won’t be another until 2021.

This is the year’s first supermoon, when a full moon appears a little bigger and brighter thanks to its slightly closer position.

The entire eclipse will exceed three hours. Totality — when the moon’s completely bathed in Earth’s shadow — will last an hour. Expect the eclipsed, or blood moon, to turn red from sunlight scattering off Earth’s atmosphere.

Everyone everywhere can catch the supermoon, weather permitting. But the entire eclipse will be visible only in North and South America, and across the Atlantic to western and northern Europe.