Lunar Eclipses

Did you know that the Moon sometimes turns deep red in the night sky? This happens during a lunar eclipse. Let's see what a lunar eclipse is.

When the Earth is perfectly aligned between the Sun and the full Moon, the Moon passes through the Earth's shadow. This phenomenon is called a lunar eclipse.

Earth’s shadow has two parts: the umbra, the darkest inner shadow where no sunlight reaches, and the penumbra, the lighter outer shadow where some sunlight still gets through.

When only part of the Moon moves into Earth's umbra, creating a mix of shadow and light, it is called a partial lunar eclipse. When the Moon moves only through Earth’s penumbra, it’s called a penumbral eclipse where the moon appears slightly dimmed.

In a total lunar eclipse, the Moon entirely moves into Earth’s umbra and takes on a reddish glow. This happens because only red light from Earth's atmosphere reaches the Moon.

Since the Earth’s shadow is much larger than the Moon and the Moon moves at a relatively slower speed, lunar eclipses last for hours.