This is a rare astronomical event that occurs when the Moon passes through the Earth's outer shadow, or penumbra. During a Planetary Penumbral Lunar Eclipse, the Moon will appear darker than usual, but not completely dark. This is a great opportunity to observe the Moon in a unique
From Wikipedia
A lunar eclipse, also called a blood moon, is an astronomical event that occurs when the Moon orbits through Earth's shadow. Lunar eclipses occur during eclipse season, when the Moon's orbital plane is approximately in line with Earth and the Sun. The type and length of a lunar eclipse depend on the Moon's proximity to the lunar node.