A lunar eclipse occurs when the Earth passes between the Sun and the Moon, causing the Earth’s shadow to be cast upon the Moon.
There are two main components to the Earth’s shadow: the outer penumbral shadow, which dims the Moon’s brightness slightly, and the inner umbral shadow, which results in the Moon appearing to darken and take on a reddish hue due to Earth’s atmosphere filtering and bending sunlight.
Lunar eclipses are safe to observe with the naked eye and provide a striking astronomical event when the Moon temporarily disappears from view.