During a lunar eclipse, the Moon passes through Earth's shadow called the Umbra.

During a lunar eclipse, the Moon passes through Earth's shadow called the Umbra.

• A. Penumbra
• B. Umbra
• C. Core
• D. Halo

Answer: (B)

Earth's shadow has two regions: a dark inner cone where the Sun is fully blocked (the umbra) and a lighter outer region where only part of the Sun is obscured (the penumbra). During a lunar eclipse the Moon moves into the dark inner shadow, the umbra, which is why a total eclipse can appear deeply dark. If only the outer shadow is involved, you’d get a penumbral eclipse, which is much subtler. The term core isn’t used for this, and halo refers to atmospheric light rings, not the Earth's shadow.

Earth's shadow has two regions: a dark inner cone where the Sun is fully blocked (the umbra) and a lighter outer region where only part of the Sun is obscured (the penumbra). During a lunar eclipse the Moon moves into the dark inner shadow, the umbra, which is why a total eclipse can appear deeply dark. If only the outer shadow is involved, you’d get a penumbral eclipse, which is much subtler. The term core isn’t used for this, and halo refers to atmospheric light rings, not the Earth's shadow.