How does a penumbral lunar eclipse differ from a partial lunar eclipse?

A lunar eclipse occurs when the Moon moves into the shadow cast by Earth. The primary difference between a penumbral and a partial lunar eclipse lies in which part of Earth's shadow the Moon enters.12

• Penumbral Lunar Eclipse: This occurs when the Moon passes through the penumbra, which is the outer, lighter part of Earth's shadow where the Sun's light is only partially blocked. Because the penumbra only slightly dims the Moon's illumination, this effect is often so subtle that it is scarcely noticeable to observers.123
• Partial Lunar Eclipse: This occurs when the Moon passes into the umbra, the central and darkest part of Earth's shadow where direct sunlight is completely blocked. A lunar eclipse is classified as partial when only a portion of the Moon's surface is immersed within the umbra and becomes darkened.123

While a penumbral eclipse involves only the outer shadow, a partial eclipse requires the Moon to enter the darker, central region of the shadow.12