Lunar eclipse guide 2018: When and where to see in the UK

On 27 July 2018 there will be a total lunar eclipse, also known as a blood moon, visible from the UK from moonrise at around 9pm.

How to see the lunar eclipse in the UK

27 July 2018

On 27 July 2018, Mars will be at opposition and a total lunar eclipse will be visible over most of Europe and Asia, Australia and South America.

Those in the UK will not be able to see the start of the lunar eclipse as the Moon will still be below the horizon at this time. However, the Moon will already be in the Earth’s umbra (the darkest part of the Earth’s shadow) and so will already start to look red. The table below shows the timings for the lunar eclipse as seen from London.

Most of these timings will apply for the rest of the UK but they might differ by a few minutes. However, moonrise times will vary depending on location. For example, the Moon will rise at 9:22pm in Edinburgh, 9:02pm in Cardiff and 9:27pm in Belfast. The Moon will also appear to be lower in the sky the further north you are.

Like our Facebook page to watch a live broadcast of the lunar eclipse through our new telescope at the Royal Observatory, Greenwich.

Lunar eclipse timings

Local time (BST) in London

Event

Direction

8:50pm

Moonrise

On the horizon in the south east

9:21pm

Maximum eclipse

This is when the Moon is closest to the centre of the Earth’s umbra, or shadow.

Very low in the south east

10:13pm

Total eclipse ends

The Moon will start to leave the Earth’s umbra and enter its penumbra (area of partial shadow) and starts to lose its red colour.

Low in the south east

11:19pm

Partial eclipse ends

The Moon has left the Earth’s umbra and has completely lost its red colour.

Low in the south east

12:28am

Penumbral eclipse ends

The Moon will look slightly darker than usual and has now left the Earth’s penumbra.

Fairly high in the south

Lunar eclipse 2018 diagram UK
Total lunar eclipse July 2018, Credit: NASA

Lunar eclipse dates UK

21 January 2019 – Total lunar eclipse

16/17 July 2019 – Partial lunar eclipse

10 January 2020 – Penumbral lunar eclipse

What is a lunar eclipse?

An eclipse of the Moon occurs when the Earth lies directly between the Sun and the Moon and the Moon lies in the shadow of the Earth.

Total lunar eclipse

During a total lunar eclipse, the Moon usually turns a deep, dark red because it is illuminated by light that has passed through the Earth's atmosphere and has been bent back towards the Moon by refraction.

Penumbral lunar eclipse

A penumbral lunar eclipse occurs when the Moon travels only through the outer, fainter part of the Earth's shadow, or 'penumbra'. This happens when the Earth moves between the Sun and Moon but the three do not form a perfectly straight line.

The penumbra causes only a slight darkening of the Moon's surface, with the Moon still exposed to some direct sunlight, so this type of eclipse is easy to miss.

Partial lunar eclipse

During the partial phase of the eclipse, part of the Moon travels through the Earth's full 'umbral' shadow. However, on this occasion only a very small section of the Moon will be covered by the umbra at maximum eclipse, though the whole northern half of the Moon will be darkened by the penumbral shadow.

Image of glass lantern slide of a lunar eclipse taken 16 November 1910 - unknown artist 1.jpg

How long does a lunar eclipse last?

Since the Earth is around four times wider than the Moon, its shadow can darken the moon for up to five hours depending on conditions.

Lunar eclipses can be seen between two and five times every year – from somewhere on the Earth’s surface. Total lunar eclipses are much rarer from one particular location.

Why are blood moons red?

People sometimes refer to a lunar eclipse as a ‘blood moon’ because of the way the Moon can turn a deep coppery red colour during its eclipse.

However, the colour of the Moon during totality will depend on the global state of dust in the Earth’s atmosphere – sometimes red or possible virtually invisible.

Dust in the atmosphere blocks out the higher frequency blue light waves, but the longer wavelength of red light comes through.

Photograph of A Tainted Eclipse © Phil Hart, Astronomy Photographer of the Year Our Moon Commended 2015

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