Penumbral lunar eclipse

This evening, June 5, there is a lunar eclipse, on the night of full Moon.

(The Moon has to be full for a lunar eclipse to happen, but it doesn’t happen every full Moon.)  But this will not be one of those total eclipses where the Moon goes totally dark and turns a deep red colour. In this case, it only passes through the edge of the Earth’s shadow, in what’s called a penumbral eclipse, so only part of it will be slightly darker than usual. And we don’t even get to see the deepest part of the eclipse from the UK. So as eclipses go, this one is pretty poor. But the Moon is fun to look at anyway, so give it a go.

The Moon is already eclipsed as it rises sometime after 9 pm, and as it gets higher you should notice that its southern hemisphere, which as it rises is on its right-hand side, is a little darker than the rest. It moves slowly out of the edge of Earth’s shadow (the penumbra) and by 10:06 the show is over and the Moon has totally freed itself from the shadow.

The exact time of moonrise varies from place to place within the UK. although the stages of the eclipse are the same wherever you are. From the south of England, moonrise is about 21:05 BST, but from the north and west it can be as late as 21:45, in which case the eclipse may be over by the time the Moon has risen above the trees.

There was a similar eclipse back in January and this is what it looked like:

Appearance of the penumbral lunar eclipse of 10 January 2020. Photo: Robin Scagell