Lunar eclipse

Definition

A lunar eclipse occurs when the Earth passes between the Sun and the Moon, casting a shadow on the Moon. This can only happen during a full moon when the Sun, Earth, and Moon are aligned in a straight line or close to it.

5 Must Know Facts For Your Next Test

1. Lunar eclipses can be total, partial, or penumbral depending on how much of the Earth's shadow covers the Moon.
2. A total lunar eclipse is often called a 'Blood Moon' due to its reddish color caused by Rayleigh scattering of sunlight through Earth's atmosphere.
3. Lunar eclipses are visible from anywhere on the night side of Earth where the Moon is above the horizon.
4. Unlike solar eclipses, lunar eclipses are safe to view with the naked eye without any special equipment.
5. The duration of a total lunar eclipse can last up to about three hours with totality lasting approximately 1 hour and 40 minutes.

Review Questions

• What causes a lunar eclipse and during which phase of the moon does it occur?
• Why does a total lunar eclipse appear red in color?
• Can you safely observe a lunar eclipse with your naked eyes?

Related terms

Solar Eclipse:

A phenomenon where the Moon passes between Earth and the Sun, blocking all or part of the Sun's light.

Umbra:

The central, darkest part of Earth's shadow where a total lunar eclipse can occur.

Penumbra:

The outer part of Earth's shadow where only a partial or penumbral lunar eclipse occurs.