“You get a true sense of the solar system moving – and that in itself is a really dramatic experience. “It will last several hours – when you get a real feeling of the Earth and moon shifting in space,” said astronomer Tom Kerss, of the Royal Observatory Greenwich, which plans to stream live pictures of the event on Friday. Unlike total solar eclipses, which occur when the moon’s disc passes in front of the sun and completely blots out sunlight for only a few minutes, a blood moon is a fairly leisurely affair. In effect, it is the light of sunrise and sunset on the Earth that will give the moon its red glow on Friday. However, its disc does not go completely dark because some sunlight – mainly the longer-wavelength, redder end of the spectrum – passes through our atmosphere and is bent around the edge of our planet so that it falls on to the moon’s surface. It is caused when the moon passes through the shadow of the Earth.

Once off the road, the climb up the Tor is. Today scientists have a more prosaic explanation for the moon’s crimson transformation. Unlike many National Trust sites, entry is free and their is no need to book your visit in advance.

Glastonbury tor falls out of sky 2018