Observing the eclipse from London on 27 July

London skyline Moonrise

The eclipse of the Moon on 27 July, 2018 will be visible from London, UK. However millions of Londoners (and all UK observers for that matter) will not be able to witness the eclipse from beginning to end. Careful planning is needed to observe as much of the eclipse as possible from the UK. From London this could prove difficult.

In London, the Moon will rise at 8:49 pm on 27th July as the total phase of the eclipse is already underway. Our natural satellite will rise in a South-easterly direction where the total phase of the eclipse will progress while the Moon is still rising. Observers will have to try to find a location with an unobstructed view of the South-eastern horizon to observe the eclipse from London.

Maximum eclipse occurs just half an hour after moonrise at a desperately low 3.5 degrees above the horizon. With many buildings dominating the London skyline, it will be difficult to even locate the Moon leave alone observing it for any prolonged period of time. The total phase of the eclipse ends at 10:13 pm with the Moon still only 9 degrees above the horizon. The eclipse finally ends at 12:28 am (28 July) 18 degrees above the southern horizon.

Eclipse Phase Time (BST)
Penumbral eclipse begins Penumbral eclipse begins (Moon below horizon) 18:14
Partial eclipse begins Partial eclipse begins (Moon below horizon) 19:24
Total eclipse begins Total eclipse begins (Moon below horizon) 20:30
Moonrise Moonrise 20:49
Maximum eclipse Maximum eclipse 22:21
Total eclipse ends Total eclipse ends 23:13
Partial eclipse ends Partial eclipse ends 00:19 (28 Jul)
Penumbral eclipse ends Penumbral eclipse ends 01:28 (28 Jul)

Return to eclipse timings where you are page

Why don’t eclipses of the Moon occur every month?

The white glow that we see from the Moon is actually sunlight being reflected back to us from the Moon’s surface. Incredibly, only 3-12 percent of sunlight is reflected back to us from our orbiting natural satellite. The Moon orbits the Earth once every 27 days. This is slightly different to the 29 days that it takes for the Moon to get from full phase to full phase again. A lunar eclipse occurs when the Moon moves directly behind the Earth in relation to the Sun (in to the Earth’s shadow) which disrupts this reflected sunlight causing it to appear an orange-red colour instead of the pearly white full Moon that we are used to.

So why don’t eclipses of the Moon occur every month?

It is often asked why then this doesn’t happen roughly every month. It is a common misconception that the Earth Moon and Sun’s orbits are all in the same plane all the time. Eclipse diagrams often appear to suggest this in order to explain the eclipse easily as shown below.

Lunar Eclipse illustration

However, although the Moon does orbit the Earth once every 27 days, the Moon’s orbit is inclined by a little over 5% compared to the Earth’s orbit around the Sun. This causes the Moon to often pass above or below the Earth’s shadow when viewed from Earth throughout the year. See illustration below.

The Moon's inclined orbit

How does the eclipse happen at all in that case?

The reason that lunar eclipses occur at all is that as the Earth progresses on its year long journey around the Sun, the Moon’s inclined orbit eventually positions itself to cause the Moon to pass directly behind the Earth relative to the Sun (in to the Earth’s shadow). Consequently, this also results in a corresponding solar eclipse 13 or so days later (or vice-versa).

Lunar eclipses can happen 2-4 times a year. As long as the Moon is above the horizon in the sky during the time of the eclipse, anyone can witness it on Earth, regardless of location (weather permitting). This effectively means around half the planet can witness some part of the eclipse.

The next eclipse?

The next total lunar eclipse will be on 28 July, 2018 visible from Western Africa, Central Asia, seen rising over South America, Eastern Africa and Europe. Setting over Eastern Asia and Australia