Partial Lunar Eclipse to Occur on 28 October 2023

Hot on the heels of the spectacular annular eclipse witnessed across America on 14 October, is a partial lunar eclipse, where the Moon will be partly covered by Earth’s shadow. But unlike the recent ‘ring of fire’, this celestial event will be visible over a much wider geographical area, with skygazers in the UK, Africa, Asia and Europe treated to the eclipse.

The partial lunar eclipse will begin in the UK at 8:35pm on 28 October 2023, with the maximum extent occurring at 9:14pm. The partial eclipse will end at 9:52pm. Either side of the partial eclipse will be around 90 minutes of a subtler eclipse, known as a Penumbral eclipse.

“Only a scant 6 per cent of the moon’s surface will undergo obscuration at the height of the eclipse,” explains from the department of physics at the University of Warwick. “Given this, the visual spectacle will be relatively understated. As such, meticulous timing is paramount for those keen on capturing the event.”

On 28 October 2023, the Moon will rise at 5:27pm in the east-northeast and will be accompanied by a bright Jupiter almost directly below. Jupiter is rapidly approaching opposition on 3 November, and will make for a pretty sight next to the partially eclipsed Moon.

The partial lunar eclipse will be visible across the UK, Europe, Africa, western Asia and western parts of Australia. Unfortunately, the eclipse will not be visible in the US.

The partial lunar eclipse will occur when the Moon is in the constellation Aries.

A penumbral eclipse will occur for around 90 minutes on either side of the partial lunar eclipse, so on 28 October 2023, we’ll get to see both a penumbral eclipse and a partial eclipse of the Moon.

Like the lunar eclipse on 5 May earlier this year, the eclipse on 28 October is not a full lunar eclipse. But unlike the May eclipse, we will be treated to a minor partial eclipse, where a modest 6 per cent of the Moon will be plunged into a darker shadow.

On 28 October, we’ll see a penumbral eclipse first. This is when the Moon passes through the lighter, outer part of Earth’s shadow; the penumbra. The effect is subtle, and you’ll need eagle eyes to see the Moon darken slightly. You will still be able to see the Moon during this phase.

After the initial penumbral eclipse, the Moon will dip into the darker, inner part of Earth’s shadow. This darker part is called the umbra, and this is what we mean when we talk about a partial eclipse.

In contrast, a total lunar eclipse occurs when the Moon passes all the way into the shadow cast by the Earth, and the Sun, Earth and Moon are perfectly aligned. When it does so, the Moon will turn a bright copper-red colour, earning it the nickname ‘Blood Moon’.

During a total lunar eclipse, the perfect alignment of the Sun, Earth and Moon causes the Moon to turn red. This is down to the Earth’s atmosphere, and the way it scatters light.

During a lunar eclipse, the only sunlight that reaches the Moon has to pass through Earth’s atmosphere (because the Earth is in the way). This means that most of the shorter wavelengths of light – the blue and green colours – get scattered by the Earth’s atmosphere, leaving behind the longer wavelengths of reds and oranges. This reddish light is refracted towards the Moon, giving it a copper-coloured hue during an eclipse.

But will the Moon still turn red during a partial eclipse? Unlike in a total lunar eclipse where the whole Moon turns red, only a small portion of the Moon will turn red on 28 October.

The effect will be subtle, but taking pictures of the Moon during the eclipse will help you discern differences. Take a look at our Moon photography guide – you only need a smartphone to get started.

During a total lunar eclipse, the Sun, Earth, and Moon are aligned perfectly, so the Earth’s shadow blocks sunlight from reflecting off the Moon. But unlike in a solar eclipse when the Sun disappears behind the Moon, the Moon does not disappear entirely. Instead, it will turn a bright, copper-red colour.

A lunar eclipse has a few different stages. First, it passes into the penumbra (the lighter, outer part of the Earth’s shadow), then into the umbra (the darker part of Earth’s shadow). It will then return to the penumbra, before finally leaving the shadow altogether.

During the partial lunar eclipse on 28 October, only the southern tip of the Moon (around 6 per cent of the Moon’s surface) will pass into the Earth’s dark umbra.

The next lunar eclipse for the UK will be a penumbral eclipse on 25 March 2024, two weeks ahead of the ‘paired’ solar eclipse on 8 April 2024. Parts of Scotland will see a rather nice partial solar eclipse at this time, while parts of Mexico, the US and Canada will see a total solar eclipse.

Similar to how a solar eclipse can only occur during a new Moon phase, a lunar eclipse can only occur during a full Moon phase. This is because a lunar eclipse occurs when the Sun, Earth, and Moon are in perfect alignment, which can only occur during the full Moon phase of the lunar cycle.

A solar eclipse is always preceded or followed by a lunar eclipse. This is simply because during a solar eclipse, the Sun, new Moon and Earth are aligned, and by the time the Moon progresses to its full phase two weeks later – the three are still roughly aligned, albeit in a different configuration, and with a full Moon rather than a new Moon.

But because the Moon’s orbit is tilted by around five degrees in respect to that of the Earth around the Sun, we don’t get eclipses every lunar cycle. It’s only when the Moon aligns with the plane of Earth’s orbit that we get an eclipse; usually, it passes below or above.

The ‘paired’ solar eclipse in this instance, was the ring of fire eclipse two weeks prior on 14 October 2023.

Dr Minjae Kim is a research fellow in the Astronomy and Astrophysics group at the University of Warwick, where they study comet dust and space debris to better understand the formation of planetary systems. Their research has been published in journals including Astronomy & Astrophysics.