{"id":59179,"date":"2024-05-22T11:15:00","date_gmt":"2024-05-22T11:15:00","guid":{"rendered":"http:\/\/128caf32-b2ba-476b-8d6d-f8773e7c4ebe"},"modified":"2024-05-22T12:08:24","modified_gmt":"2024-05-22T12:08:24","slug":"ever-seen-a-ring-of-fire-in-the-sky-this-is-what-causes-an-annular-solar-eclipse-and-why-its-different-from-a-total","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/ever-seen-a-ring-of-fire-in-the-sky-this-is-what-causes-an-annular-solar-eclipse-and-why-its-different-from-a-total\/","title":{"rendered":"Ever seen a ring of fire in the sky? This is what causes an annular solar eclipse and why it’s different from a total"},"content":{"rendered":"

An annular solar eclipse is also known as a ‘ring of fire’. But what is it, and how does it differ from a total eclipse? <\/p>

By <\/p>

Published: Wednesday, 22 May 2024 at 11:15 AM<\/p>

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Have you ever heard of an annular solar eclipse? They’re also known as a ‘ring of fire’ eclipse, and are spectacular to behold.<\/p>

Observers in North America most recently were able to enjoy one in 2023, during the October 14 annular solar eclipse<\/a>.<\/p>

And observers will be able to see the next annular eclipse on October 2, 2024 over Easter Island, Chile and Argentina<\/a>.<\/p>

In this guide we’ll reveal what an annular solar eclipse is, why they happen and how they differ from a total solar eclipse<\/a>.<\/p>

Read our guide to find out when the next eclipse<\/a> is occurring.<\/em><\/strong><\/p>

An annular solar eclipse seen from orbit by the Hinode X-Ray Satellite, 25 October 2022. Credit: JAXA\/NASA\/Smithsonian Astrophysical Observatory<\/figcaption><\/figure>

What annular solar eclipses look like<\/strong><\/h2>

The mention of a solar eclipse conjures thoughts of totality and a glimpse of the Sun\u2019s ghostly corona, the outermost part of its atmosphere, as day turns to night.<\/p>

These are two effects of a total solar eclipse, but an annular solar eclipse is quite different.<\/p>

Although the corona remains out of sight and daylight persists during an annular eclipse, they have other spectacular features, notably the \u2018ring of fire\u2019.<\/p>

Observers see a thin, burning \u2018ring\u2019 around the Moon as 90% of the Sun is blocked.<\/p>

\"Sequence
Sequence showing the 2019 annular solar eclipse from start to finish. Credit: Goh Keng Cheong \/ Getty Images<\/figcaption><\/figure>

The remaining 10% of the Sun\u2019s face that remains visible around its perimeter is enough for daylight to persist<\/p>

And to mean that an annular solar eclipse can only be safely viewed through eclipse glasses<\/a> or solar filters.<\/p>

So what exactly is going on when annular eclipses occur, and why do they differ from total solar eclipses?<\/p>

Annular solar eclipse vs total solar eclipse<\/strong><\/h2>
\"Total
Total eclipse vs annular eclipse explained. Annular eclipses occur when the Moon is further away from Earth; when the Moon is closer to Earth and so appears larger, a total eclipse can occur. Credit: BBC Sky at Night Magazine<\/figcaption><\/figure>

An annular solar eclipse happens when the Moon appears smaller than the Sun as it crosses its disc, and so doesn\u2019t block out all of its light.<\/p>

This happens because the Moon\u2019s orbit around Earth is not a perfect circle but a slight ellipse shape. <\/p>

There\u2019s a point in the Moon\u2019s orbit when it\u2019s nearest Earth, perigee<\/strong>, and appears big enough to block the Sun\u2019s disc<\/p>

And a point when it\u2019s farthest away, apogee<\/strong>, and doesn\u2019t appear to cover the Sun.<\/p>

\"Total
Total eclipse vs annular eclipse visually. The comparative sizes of perigee (nearest) and apogee (farthest away) Moons, and the two different types of eclipses they create. Credit: BBC Sky at Night Magazine<\/figcaption><\/figure>

The distance from the Moon to the centre of Earth changes from a maximum of around 406,000km at apogee to around 357,000km at perigee.<\/p>

Whether there will actually be an eclipse in any given orbit of the Moon around Earth depends on whether the new Moon crosses the ecliptic<\/a> \u2013 the apparent path of the Sun across the sky.<\/p>

When an eclipse does occur during a perigee new Moon, it creates a cone-shaped umbral shadow in space.<\/p>

And where the tip of this shadow touches Earth\u2019s surface we see a total solar eclipse.\u00a0<\/p>

The ‘ring of fire’ explained<\/strong><\/h2>
\"An
An annular solar eclipse is also known as a ring of fire. Premjith Narayanan captured this one from Bahrain, 26 December 2019. Equipment: Canon EOS R mirrorless camera, Canon EF 300mm f\/2.8L IS USM lens<\/figcaption><\/figure><\/div>

During the maximum phase of a total eclipse, along a narrow path of totality it\u2019s possible to experience darkness in the day, as all of the Sun is obscured.<\/p>

But when an eclipse happens at an apogee new Moon it\u2019s not possible to witness totality anywhere.<\/p>

During an annular solar eclipse the dark \u2018umbral\u2019 shadow cast by the Moon isn\u2019t long enough to reach Earth.<\/p>

This means observers along the path of annularity see a \u2018ring of fire\u2019.<\/p>

Phases of an annular solar eclipse<\/strong><\/h2>
\"CAPTION:
The phases of an annular solar eclipse, from partial to \u2018ring of light\u2019 and back again. Credit: Mattia Verga from Pixabay.com<\/figcaption><\/figure>

What happens before and after maximum eclipse is very similar for both an annular and a total eclipse. <\/p>

For around 80 minutes or more either side of totality or annularity, there\u2019s a partial solar eclipse.<\/p>

The new Moon approaches to take an increasingly larger bite out of the Sun, before moving away.<\/p>

The difference is the few minutes in the middle.<\/p>

Just as with a total eclipse, during an annular solar eclipse it makes a difference where you stand within the central path of annularity.<\/p>

Along the centre line, the \u2018ring of fire\u2019 lasts the longest \u2013 up to 12 minutes.<\/p>

But this decreases to just a second on the northern or southern edges of the path.\u00a0<\/p>

Those at the edge of the path may seem disadvantaged, but there\u2019s a reason why some eclipse-chasers gather there.<\/p>

Although a perfect \u2018ring of fire\u2019 is only momentarily visible, from these positions it\u2019s possible to see Baily\u2019s beads \u2013 spots of sunlight pouring through lunar mountains and valleys.<\/p>

They flare for a few seconds and cause a \u2018broken ring\u2019. <\/p>

\"The
During an annular eclipse it’s possible to see Baily\u2019s beads. Credit: John Finney Photography \/ Getty Images<\/figcaption><\/figure>

Observing upcoming annular solar eclipses<\/strong><\/h2>

The next annular solar eclipse will occur on October 2 2024 in the Pacific Ocean.<\/p>

Perhaps the best place to witness annularity will be amid the carved human moai figures on Rapa Nui (Easter Island).<\/p>

It will also be visible shortly before sunset from Patagonia in southern Chile and Argentina.\u00a0<\/p>

\"An
An annular solar eclipse as seen on 21 June 2020 over Xiamen, Fujian Province, China. Photo by Huang Shan\/VCG via Getty Images.<\/figcaption><\/figure>

Eclipses are spectacular sights, yet we exist at a time when the Moon and Sun can be exactly the same apparent size in the sky to make total solar eclipses possible.<\/p>

However, the Moon is slowly drifting away from Earth at a rate of 4cm per year.<\/p>

There will come a time when it will no longer appear big enough to cover the whole Sun.<\/p>

In about 563 million years, every solar eclipse will be annular.<\/p>

How to safely observe a solar eclipse<\/strong><\/h2>

Whether a total or an annular eclipse, when observing the Sun, caution must always be exercised.<\/p>

Never look directly at the Sun with the naked eye, as doing so could seriously damage your eyesight.<\/p>

For more info, read our guide on how to safely view an eclipse<\/a>, or watch our video below:<\/p>