Caoimhín's Content

Rather than looking at what’s visible in the sky right now, this video goes as far into the future as necessary to see the next eclipses. Eclipses seem rarer than they are, as they are usually only visible from a particular part of the Earth, and they move around. While a solar eclipse might be almost a once in a lifetime event for any given place, moving to find an eclipse can help you see a lot more.

Given that Ireland has just had a partial lunar eclipse, in October, it made sense to start with the next total lunar eclipse. It just so happens that the next total lunar eclipse will be visible from the Ireland. Unfortunately we will have to wait a while, until March 2025. The difference between a total lunar eclipse and a partial lunar eclipse is how much of the Moon is in the Earths shadow. If it’s all of the Moon, then it’s a total eclipse, if it’s not then it’s not. This definition doesn’t take into account how much of the eclipse you actually see. If you catch the start of a total eclipse, but not the whole thing, it is still a total eclipse, even if you only see part of it.

This is unfortunately the situation for us in Ireland for the March 2025 lunar eclipse. It will be a total eclipse, but we won’t see all of it from Ireland. For us, the eclipse will begin early in the morning, a bit after 3am. The eclipse itself will run until practically 10am, but of course by then the Sun will have risen for us, and the Moon will have set. We only get to see about half of the Moon eclipsed before it dips below the horizon, but from other locations on Earth the whole event will be visible. Thanks to the wonders of modern technology (Stellarium in this case), we aren’t limited to Ireland. Just as we can travel years into the future, we can travel kilometers around the globe, in this case all the way into the Pacific.

Just off the western coast of the Galapagos Islands is pretty much the perfect place to see this eclipse. Travelling halfway around the world can cause a bit of confusion, so do forgive the slight mistake I make in the video. The eclipse of course can’t run from 6am till 3am, blame it on the jet lag. Rather, the eclipse will begin at around 3am, and reach totality at a bit after 6am. The midpoint of the eclipse, when the whole Moon looks red is what we travelled for and that is what we get to see. As the Suns light moves through our atmosphere it is bent and scattered, giving our shadow a lovely red colour. Total lunar eclipses are often called “Blood Moon’s” for this reason. We might not get to see the whole thing, but even seeing half the Moon turn red is pretty impressive, and we will get to see that here in Ireland just before the Sun comes up.

Stellarium doesn’t just let you travel around the Earth, but around the solar system. Thanks to this, we can go to the Moon and see the lunar eclipse in reverse. What does a lunar eclipse look like on the Moon? A bit like a solar eclipse, and of course it is. When the Moon is in our shaow, the Earth blocks the view of the Sun, just as the Moon does for a solar eclipse on the Earth. The Earth takes up a lot more room in the Moon’s sky than the Moon does in our sky, so the Eclipse lasts much longer. However, because the Earth blocks out the whole Sun, and a bit of the area around it, the Earth eclipsing the Sun on the Moon doesn’t look quite as impressive as a solar eclipse viewed from the Earth.

The very next solar eclipse is actually little closer to the date of this post, just a next year in April 2024. Unfortunately, this eclipse won’t really be visible from Ireland at all. instead, the path of the eclipse will move from the South Pacific, into Mexico, through the U.S.A, and into Canada as it finishes up. Around the north of Mexico or the southern part of the United States is the best place to see it, so that is where we go. In the video, I originally under-estimate how far south is best, and end up viewing the eclipse from a little too far north. Luckily, when you are using software you can correct such mistakes easily. In real life, proper planning is important for ensuring you see any eclipse under the best possible conditions.

A total solar eclipse is an amazing thing to see. Once the disc of the Moon blocks out the Sun, all you are left with is the corona. Coming from the Latin for crown, the corona is the ring of glowing filaments of plasma extending around the Sun. Solar flares and coronal mass ejections arc away from the Sun’s surface all the time, the Sun is always surrounded by these hazy threads of plasma. Normally, they are invisible from the Earth, but during a total eclipse we get to see them. Even during an eclipse, it’s important to protect your eyes, but with the proper eye protection the corona of the Sun becomes visible. This is only possible because the Moon and the Sun are just the right sizes and just the right distances form the Earth to fit together perfectly. If the Moon was a little further away or smaller, we would only ever get an annular eclipse, or even just a transit. This would allow too much sunlight, preventing us from clearly seeing the fainter corona. If the Moon was bigger or closer, it would block the Sun and it’s corona, just like the Earth does for the Moon during a lunar eclipse.

One way to highlight this difference is to look at a solar eclipse on the Earth from the surface of the Moon. After briefly going to Mimas by accident, that’s exactly what we do here. Immediately, you can see the Moon’s shadow on the Earth. Compared to our shadow engulfing the whole Moon, this shadow is just a circle on an otherwise illuminated globe. By moving through the time of the eclipse, we can see the shadow travelling across the Earths surface, from practically New Zealand up into the North Atlantic. This also gives us a good view of the umbra and the penumbra. The darkest part of the shadow is the umbra, and this is surrounded by the lighter partial shade of the penumbra, making the shadow of the Moon almost look like a bull’s eye or target.

Eclipses are surprisingly regular, and the Earth gets many eclipses each century. These eclipses do move around from place to place, so seeing an eclipse twice from the same location can take a lot more waiting. For the next total solar eclipse visible from here in Ireland, we’re waiting all the way till 2090. This eclipse will happen just before sunset, which already puts it in a difficult position to observe. Based on the view generated by this software, it looks like the best place to view it would be a little off the southern coast of Ireland, but I guess we’ll have to wait and see.

I really hope you enjoyed this piece, it’s a little different from my usual “this is what you can see right now” focus. I do intend on making more videos and posts like this, but there will still be plenty of current updates on what’s visible in the future, I hope you come back to take a look.