If you love skygazing, you won’t want to miss the spectacular ‘blood moon’ set to light up the sky tonight.
A blood moon, also known as a total lunar eclipse, occurs when the Earth is positioned precisely between the sun and the moon so all three are in a line.
During this event, the moon takes on a coppery reddish hue due to a quirk of how the sun’s light interacts with Earth’s atmosphere.
Tonight’s blood moon is visible only for people the side of the Earth that is in night time when the eclipse occurs – namely North and South America and western parts of Africa and Europe, including the UK.
Best of all, you won’t need any special equipment whatsoever to see the blood moon, which will look more like Mars than its usual pearly white.
‘The best time to see the eclipse will be sometime after 5am and before the sky gets too bright,’ said Professor Don Pollacco, astronomer at the University of Warwick.
A total lunar eclipse occurs on average every 2.5 years – the last one visible from the UK was May 2022 – so it’s not a very common sight, and one not to be missed!
Here’s how to see the awe-inspiring spectacle.
A blood moon during an eclipse in Santiago, Chile, 15 May 2022. The moon in total eclipse appears reddish in colour when it’s illuminated by sunlight that’s filtered and refracted by Earth’s atmosphere
Pictured is what the total lunar eclipse will look like from Britain. The blood moon, or lunar eclipse, will start from 06:26 GMT and continue until 07:31 GMT (UTC)
What is a blood moon?
‘Blood moon’ is not a scientifically recognised term according to experts, but a nickname picked up due to its stunning red hue.
The terms ‘blood moon’ and total lunar eclipse are used interchangeably because they refer to the same astronomical event.
During a total lunar eclipse – when the moon moves into the Earth’s shadow – the moon always appears red due to a phenomenon called ‘Rayleigh scattering’.
‘During this period as sunlight can no longer reach the moon you might expect it to be invisible,’ explains Professor Pollacco.
‘But instead a small amount of sunlight reaches the moon after passing through the Earth’s atmosphere and this light is then reflected off the lunar surface making it visible to us on Earth.
‘As the sunlight travels through our atmosphere on its way to the moon, the redder wavelengths pass through relatively unhindered while the bluer wavelengths are scattered (that’s why the sky is blue) by dust suspended in the earth’s atmosphere.
‘The red light reaches the moon and is then reflected back to us.’
A blood moon occurs when the moon passes into the shadow, or umbra, cast by the Earth. Light from the sun then refracts through the Earth’s atmosphere and bounces of the moon
The eclipse will be best viewed over the US where all states will be able to see the full length of ‘totality’. In the UK, the moon will be much lower on the horizon and the eclipse will occur closer to dawn
Those in the west of the UK will see the eclipse from about 4:00am and will be able to watch as the moon turns red in Earth’s shadow. However, the East of the country won’t be under the path of the eclipse so they will only see about 90 per cent coverage
How do I see the blood moon?
While people in North and South America will get the best views of the eclipse, British space fans should still be able to catch a glimpse in the early morning before the sun rises.
The moon will start to enter Earth’s shadow at 03:57 GMT with totality lasting from 06:26 until 07:31 GMT.
Initially, skygazers will see the edge of the Earth’s shadow pushing across the lunar surface, making it appear to vanish from our perspective, but as the Earth’s shadow completely covers the moon (a period known as ‘totality’) the moon will start to glow bright red.
‘While this eclipse is best seen from the other side of the Atlantic, observers on the western side of the UK will see the total phase start before morning twilight at about 4am when the Moon is low in the western sky,’ said Professor Pollacco.
‘From the rest of the UK, the eclipse will not be total (the moon will be greater than 90 per cent obscured) but should still be a striking spectacle.’
Blood moon should be close to the horizon, which will also affect how we perceive its size, according to the academic.
Our brains experience something called the ‘Moon Illusion’, which causes the moon to appear bigger when it is near the horizon, but scientists still aren’t sure why or how it works.
During a total lunar eclipse, the moon can look more like Mars with a rusty red hue, different from its usual pearly white
Blood Moon, a full moon that coincides with a full lunar eclipse and that has a reddish appearance, rises over the city of Rio de Janeiro, Brazil on May 15, 2022
The first time a blood moon was documented was in January 1137. A total lunar eclipse occurs on average every 2.5 years – the last one visible from the UK was May 2022 so it’s not a very common sight. Pictured, the super blood moon as seen from Skopje, Republic of North Macedonia
To ensure you get a good view tonight, find an area with a good view of the horizon to the west where the sun will be setting.
Since the moon will be bright and it will be close to dawn, getting away from light pollution isn’t much of a concern.
But, if you can, getting away from bright streetlights and letting your eyes adjust to the dim light conditions will help you see more details of the lunar surface.
Unfortunately, the weather conditions for viewing the blood moon will not be ideal for most of the UK.
A Met Office spokesperson told MailOnline: ‘The current forecast for the lunar eclipse shows some cloud breaks on Friday night in parts of the UK, particularly in some western areas.’
WHAT IS A LUNAR ECLIPSE?
An eclipse occurs any time a planet or moon passes between another planet, moon or the sun.
Depending on their orbits, they can be total or partial.
A lunar eclipse is a specific event which happens when Earth lines up directly between the sun and the moon.
When this happens, Earth blocks the light from the sun to the moon. Earth’s shadow then falls on the moon.
During a lunar eclipse, we can see Earth’s shadow on the moon.
They can last for several hours, but it is rare for a period of total eclipse to last longer than 100 minutes.
At least two lunar eclipses happen every year.
The moon will also be slightly closer to the Earth, causing it to appear brighter than usual, dubbed a Super Moon. These unique factors, when combined, result in a ‘Super Blood Wolf Moon’. This graphic shows how a lunar eclipse occurs
