This month, on the 29th to 30th of November, a penumbra lunar eclipse will be visible on Earth.

Since the moon rotates around the Earth daily, there are times when it will be in a position when it is either covering the sun or in the Earth's shadow. Both of these examples are called eclipses; when the moon covers the Sun, a solar eclipse is occurring. When the Earth is in between the Sun and the moon, however, it is known as a lunar eclipse.

A lunar eclipse can be seen when the moon moves into the shadow of the Earth, causing the moon's colour to vary due to the lack of light. Only a small part of the world, in this case North and South America and some parts of South-east Asia, can witness this event because it doesn't last long and it must be dark in order to be visible.

This is a visibility map for the November 29th/30th penumbra eclipse.

Now, this upcoming eclipse is known as a penumbra lunar eclipse, rather than a total lunar eclipse. Why is that? There are two main parts of the Earth's shadow: the umbra and penumbra. The umbra is the darkest part of the shadow, while the penumbra is lighter due to the angles of sunlight. A total lunar eclipse would eliminate all sunlight on the moon's surface as it enters the umbra, but since this upcoming lunar eclipse will show the moon only reaching the earth's outer shadow, it is not a total lunar eclipse. The moon will barely darken, contrary to the red moon we'd see on a total lunar eclipse.

While watching the penumbra eclipse, there are a few notable events. First, of course, there is the moonrise. After is the beginning of the eclipse, when the moon first enters the penumbra. The most notable moment is during the maximum eclipse, when the largest part of the moon is in the penumbra. Then it happens all again, but backwards, as the moon leaves the Earth's shadow. The eclipse would end, and then comes the moonset. For this particular eclipse, it will be harder to see when the moon reaches the maximum eclipse as the colour will not darken much.

This is a diagram of the umbra and penumbra of the Earth's shadow.

This upcoming penumbra eclipse will be the last eclipse of 2020, so if you're somewhere in the west, don't forget to check out the eclipse on the night of November 29th!

Glossary:
penumbra eclipse: a lunar eclipse that occurs when the Moon becomes completely immersed in the penumbra cone of the Earth without touching the umbra

eclipse: an obscuring of the light from one celestial body by the passage of another between it and the observer or between it and its source of illumination

lunar eclipse: an eclipse in which the moon appears darkened as it passes into the earth's shadow

umbra: the fully shaded inner region of a shadow cast by an opaque object, especially the area on the earth or moon experiencing the total phase of an eclipse

penumbra: the partially shaded outer region of the shadow cast by an opaque object, especially the area on the earth or moon experiencing the partial phase of an eclipse

CONTENT CREATED BY MarineBiologie