A penumbral eclipse occurs when the Earth passes between the Sun and the Moon, but they are not perfectly aligned. During this type of eclipse, the Moon moves into the outer part of the Earth's shadow, known as the penumbra. As a result, the Moon experiences a subtle shading, making it appear slightly darker than usual. Unlike a total or partial lunar eclipse, a penumbral eclipse can be challenging to observe because the changes in the Moon's brightness are minimal. Observers may notice a gradual shading across the surface of the Moon, but it does not completely disappear.