The longest total lunar eclipse of the 21st Century will take place on Friday evening as the Earth, Sun and Moon perfectly line up.
A BBC explainer has outlined how long the total lunar eclipse will last, where is best to see the eclipse, and why it is called a blood moon.
The BBC said: “The longest total lunar eclipse of the 21st Century is coming on 27 July 2018.
“The total eclipse phase will last for one hour and 43minutes from 20:21.”
The explained then answered frequently asked questions about the historic event.
It explained how a total lunar eclipse takes place “when the moon passes into the Earth’s shadow.”
The reason there is not a lunar eclipse every month is because the “moon won’t pass through the Earth’s shadow every month as its orbit is tilted”.
The historic event is called a “blood moon” because “many colours from the sunlight are scattered by the Earth’s atmosphere”.
It added: “But red’s longer wavelength gets through, bending towards the moon giving it a reddish glow.”
The lengthy time for the lunar eclipse is because the moon will “pass into the darkest region of the Earth’s shadow called the Umbra”.
Stargazers hoping to catch a glimpse of the longest total lunar eclipse of the 21st Century should get a view from Europe, Asia, Africa, Australia and New Zealand.
Astrophysics professor Tim O’Brien said: “You need to have a clear south-eastern horizon as the moon comes up so we low-down in the south-east.
“As it rises, you’ll see it more and more clearly and then the eclipse finishes at about a quarter past 10pm.
“It’s just lit by the light that’s filtered through the Earth’s atmosphere which is why it looks this sort of dusty red.”
In the UK, the beginning of the eclipse will not be visible as it will be below the horizon, but the maximum eclipse through to the end of the eclipse will be visible from 9.21pm BST.
Nigeria, Congo, Angola and Morocco will be able to see the Blood Moon from 8.30pm local time.
Germany, Spain, France, Italy, Egypt, South Africa and Austria will all be able to witness the whole of the Blood Moon from 9.30pm local time.
Unfortunately Canada, Greenland and North and South America will not be able to witness the Blood Moon as it will not be in the right position.
The next lunar eclipse will take place on January 21 2019.