Lunar eclipses

Many times a year, approximately four to seven times, our Earth, Moon, and Sun align perfectly to create a giant cosmic spectacle called an eclipse. The Moon’s orbit around the Earth is slightly inclined compared to the Earth’s orbit around the Sun. It is this inclination that explains why we don’t have eclipses every month but only occasionally.

Here, we will explore lunar eclipses.

Lunar eclipses occur during a full moon. When the Earth is positioned directly between the Moon and the Sun, the Earth’s shadow falls on the surface of the Moon, making it darker and sometimes even giving it an astonishing red hue over the course of a few hours. Each lunar eclipse is visible from half of the Earth.

The Moon moves into the inner part of the Earth’s shadow, called the umbra. Some of the sunlight passing through the Earth’s atmosphere reaches the surface of the Moon, illuminating it faintly. Colours with shorter wavelengths, like blue and violet, disperse more easily than colours with longer wavelengths, such as red and orange. Because these longer wavelengths pass through the Earth’s atmosphere, and the shorter wavelengths are scattered, the Moon appears orange or reddish during a lunar eclipse. The more dust or clouds in the Earth’s atmosphere during the eclipse, the redder the Moon appears. It’s a bit like the Moon putting on its red coat for the evening!

When the Sun, Earth, and Moon do not align perfectly, the Moon passes through only part of the Earth’s inner shadow, called the umbra. The shadow grows and recedes without ever completely covering the Moon. It’s as if the Moon grazes the Earth’s shadow, playing hide-and-seek with it but never fully hiding. This is called a partial lunar eclipse, where the Moon winks at the Earth’s shadow before continuing its journey.

If you’re not aware, you might miss it! The Moon travels through the penumbra of the Earth, the outer and lighter part of its shadow. It darkens so subtly that it can be challenging to notice. Imagine the Moon passing through a zone of light shadow, adding a small mysterious touch to its usual brightness.