There will be a total eclipse of the Moon visible from the UK on 21st January. This will be the last total lunar eclipse here until 2029. A total lunar eclipse occurs when the Earth passes exactly between the Sun and the Moon. The Sun is behind the Earth, and the Moon moves into the Earth’s shadow.
Sometimes an eclipsed Moon is a deep-red colour, other times it remains quite bright. The exact colour depends on how light from the sun is being scattered, Rayleigh scattering, by molecules and particles in the Earth’s atmosphere, blue light is scattered away more than red.
You only get to see a total solar eclipse if you are in the narrow path of the Moon’s shadow, but a lunar eclipse is visible wherever the Moon is above the horizon at the time, so each one can be seen from a large area of the Earth. For that reason, they are much more common from any given location. Lunar eclipses always happen at a full Moon as this is when it moves behind the Earth and into line with the Earth and Sun. A full Moon happens every month, but most of the time no eclipse takes place.
The lunar eclipse on 21st January begins with penumbra at 02h35 GMT, umbra at 03h33 GMT and totality from 04h40 GMT. Mid-eclipse is at 05h12 GMT, which is when the whole Moon will appear red. The red will fade by 05h43 GMT. Coming out of the other size penumbra ends at 07h49 GMT.
the lunar eclipse will also be visible from north-western France, north-western Spain, Portugal, a small part of West Africa, almost the whole of North and South America, the eastern Pacific, and the north-eastern tip of Russia.
Lunar eclipses are very easy to witness as no special equipment or safety precautions are required. To watch the lunar eclipse on 21st January all you have to do is get up early, wrap up warm and step outside, unless of course you’re lucky enough to have a bedroom window facing the moon at that time. If you can see the full Moon you will be able to observe the eclipse as it happens.
I double-checked that this is the last proper total lunar eclipse for the UK until 2020. Astrobuddy confirmed that is indeed the case: “That’s the next that is fully observable from the UK. There are others that we see parts of before then, e.g. May 16, 2022, when the Moon sets during totality,” he told me.