Penumbral lunar eclipse: how rare is it and when is it visible?

Stargazers can enjoy two lunar eclipses in 2023 and the next one is just around the corner.

A penumbral lunar eclipse will occur on Friday (May 5) and while it is the least dramatic of the three types of eclipse it is still a date for the diary.

“The faint outer part of Earth's shadow is cast across the lunar surface,” space.com says about the event. “This type of eclipse is not as dramatic as the other two and can be difficult to see.”

This is all you need to know about penumbral lunar eclipses.

How common are penumbral lunar eclipses?

There are three types of lunar eclipse. Total, partial and penumbral.

Nasa’s data shows there have been nine penumbral variations in the past 10 years, compared with seven total eclipses and three partials.

The last penumbral eclipse was in November 2020.

How can I watch a lunar eclipse?

According to space.com, the display should be visible in south and east Europe, much of Asia, Australia, Africa, the Pacific, Atlantic and Indian oceans and Antarctica.

British astrologists can view the eclipse on a web broadcast on space.com

The next total eclipse will be in April 2025 and there is set to be a partial eclipse later this year.

Should you be in a position to watch the event for yourself, “you simply go out, look up and enjoy”, space.com says. “You don't need a telescope or any other special equipment.”

But it might not be worth the effort.

“To be honest, penumbral lunar eclipses are not that exciting if you’re just looking at the Moon,” Bob Berman wrote on almanac.com. “The full moon really doesn’t change its appearance during a penumbral eclipse as it does during a total eclipse of the Moon. This is a very subtle kind of eclipse, which may appear like a darker-than-usual Moon. Sometimes there’s a very slight grey shading on one part of the Moon, but almost nobody notices it.”