As the moon prepares to blot out the surface of our sun in two weeks, it’s warming up with a penumbral lunar eclipse on Sunday night or Monday morning, depending on your time zone.

In general, eclipses are the result of a delicate dance between the moon, the sun and the Earth. Lunar eclipses occur when the planet slides between the sun and the moon. That’s in contrast to a solar eclipse, which happens when the moon interjects between the other two bodies.