NASA | Lunar Eclipse Essentials in 3D

The video explains the phases of the moon, which occur monthly, and the phenomenon of lunar eclipses, which happen twice a year. During a lunar eclipse, the moon passes through Earth's shadow, turning red due to atmospheric scattering of light. The process involves the moon moving through the penumbra and umbra, with the red color resulting from longer wavelengths reaching the moon. The eclipse is brief, lasting from minutes to hours.

What causes the moon to appear different over the course of a few weeks?

• The moon's distance from the Earth changes.

• The moon's orbit around the Earth.

• The Earth's rotation on its axis.

• The sun's position in the sky.

What is a lunar eclipse?

• When the moon is completely illuminated by the sun.

• When the sun is directly between the Earth and the moon.

• When the moon passes through the Earth's shadow.

• When the moon is closest to the Earth.

During a lunar eclipse, what is the penumbra?

• The area where the moon is completely dark.

• The area where the sun's light is partially obscured.

• The area where the moon is fully illuminated.

• The area where the Earth's shadow is weakest.

Why does the moon appear red during a lunar eclipse?

• The Earth's atmosphere scatters shorter wavelengths of light.

• The moon is closer to the sun.

• The moon's surface changes color.

• The sun's light is completely blocked.

How long does a lunar eclipse typically last?

• Several days.

• An entire day.

• A few seconds.

• A few minutes to a few hours.