Caoimhín's Content

As we are now into the month of April, it is time to take a look at the eclipse. The total solar eclipse will be occurring on April 8th, just a week after this video. This eclipse has been called the Great American Eclipse and it will be visible to some degree over a large stretch of North America. We won’t be able to see it from here in Ireland, but it can already been seen in software like Stellarium that the New Moon is very nearly in front of the Sun. Following the Moon and the Sun into the West as they set, we can almost see the disk of the Moon beginning to contact the disk of the Sun. As our portion of the Earth here in Ireland turns away from the Moon and the Sun, the Moon will continue in its orbit until it is in front of the Sun. By removing the ground from our view, we can continue to follow its progress, watching the dark disc of the Moon crossing in front of the Sun. Unfortunately, even following the eclipse to its peak, from a latitude as high as ours the eclipse is only partial, not total. We continue to see a small sliver of the Sun peeking out from above the Moon. For anyone as high on the Earth as Ireland, such as people in the North of Newfoundland, or further North in places like Nunavut, you will be essentially looking over the Moon, allowing some of the Sun’s light to continue onto the Earth. In the video, using the rough location map of Stellarium, it takes a few goes before I get to a good location, but it does show how the eclipse will look from near, but not on, the path of totality.

Starting a little bit high and a little far to the East, the view shown from the South and East of the Great Lakes in the Northern United States. The path of totality will pass across the other side, under the Northern coast of the Great Lakes. This view is very close to the path of totality, with a large portion of the Sun obscured. Although the eclipse isn’t exactly total, Jupiter and Venus can be faintly seen as the sky dims. This view is still only showing a level of light pollution similar to Cork City, but luckily light pollution should be slightly less of a problem during the day. If the streetlights in your area are on a timer, then there is a good chance that they won’t turn on during the eclipse, keeping the sky dark. On the other hand, if the public lighting in your area turns on in response to darkness, the eclipse might get dark enough to trigger them. Many streetlights and garden lights use sensors to tell if they should come on or not, often a Light Dependent Resistor or LDR. These resistors resist less when light is hitting them, and this can be used to trigger lights to come on once a certain level of light is reached. Any manually operated lights in your area of course could go either way, although I think it is most likely that lights will be left off. Even under the best conditions, the peak of the eclipse will only last for a bit less than 4 minutes, so it won’t be dark for that long.

A large portion of the center of the United States will experience totality, as the shadow of the Moon travels from roughly Texas to Indiana and then up and across to New England. The eclipse will appear to last the longest for those close to the middle of the path, lasting just a minute or two for those at either end. Given my unfamiliarity with the USA, I do manage to miss the path of totality again on my second attempt, showing a slightly less total eclipse again compared to my first attempt. In real life, proper planning can help you avoid such a mistake. Luckily my third attempt, close to the point where the eclipse path passes from Mexico into the USA, is right on the path of totality.

At the moment of totality, not a single part of the Suns bright disk is visible. The Moon perfectly blocks out the brightest part of the Sun, leaving the fainter corona visible. The corona of the Sun is much like its atmosphere, although the Sun is a ball of plasma, and so doesn’t really have a hard defined surface. The filaments of glowing plasma stretching out from the Sun are visible either side of the Moon. You might be able to see how arcs curve roughly from pole to pole, following the Sun’s magnetic field. Some of the loops extending out from the Sun are coronal mass ejections, solar flares that can send high energy particles streaming towards the Earth, causing our auroras when the particles collide with our upper atmosphere. With the sky darkened, Jupiter and Venus appear again, but here at a place in absolute totality, Saturn and Mars may be visible as well.

If you are planning on observing the eclipse, I’m sure you’ve seen that you need to protect your eyes. The protective eyewear is designed to block out some light, making the eclipse safer to observe. This might make it hard to see the planets, especially the fainter Saturn and Mars. Even so, do not remove your protective eyewear. As soon as the eclipse begins to end, the sky will brighten very quickly, quicker than your pupil can react, and this can be dangerous. I recommend setting up a camera or telescope with the right protection to safely observe during an eclipse.

Removing any last traces of light pollution should help, and even though it shouldn’t be a problem for most places during the eclipse, going to a dark sky is still the best way to guarantee an ideal view. IN a truly dark sky, bright stars may be visible as well as the planets, including part of the constellation of Orion. Not as easily visible, is the planet Mercury and the comet, 12P/Pons-Brooks. Both of these faint objects are out next to the Sun, but may be too faint to see with the naked eye, even during the peak of the eclipse. It is really these two objects that I recommend a camera for, as they may be too difficult to capture with the naked eye. Jupiter and Venus are the brightest objects in the sky, and should be reasonably visible, and while Saturn and Mars are fainter they are potentially visible under good conditions. However, seeing five planets in the sky during a solar eclipse is pretty special, so taking the precautions the to see Mercury might be worth it, and having a comet in view as well is spectacular. Comet 12P/Pons-Brooks only comes around once every 71 years, so it popping up during an eclipse could easily be considered a once in a lifetime event.

A solar eclipse on its own, luckily, isn’t a once in a lifetime event. If you’re willing to travel around the world, eclipses happen reasonably regularly, there will be more solar eclipses in your lifetime if you don’t get to see this one. In fact, there is an annular solar eclipse visible in South America in October this year, 2024. If an annular or partial won’t do, you only have to wait until 2026 for a total solar eclipse in August, visible across parts of Europe. As it occurs on the 12th of August, you might be lucky enough to see some of the Perseid Meteors during the eclipse. An eclipse in August 2027 will cross most of Northern Africa, with another in 2028 crossing Australia. I will no doubt be checking these out as they approach, but I can say for certain that they won’t have comet 12P/Pons-Brooks.

The absolute best view of an eclipse like this might be from orbit around the Earth. If your orbit takes you through the path of totality, the Moon will still line up with the Sun, though without a blue sky to darken it may look a little less impressive. Then again, without the atmosphere to get in the way, fainter objects may be more visible. For lucky astronauts on the ISS, if it goes past the right area, they will also be able to see the shadow of the Moon on the Earth. This is a lot easier to achieve, as the umbra of the Moon is huge and will be visible from Low Earth Orbit even kilometers to either side of the path of the eclipse itself. Given how the ISS orbits the Earth, there is a good chance the astronauts on board will atleast see the eclipse from the outside, even if they don’t pass directly through it.

Another location you might see the shadow of the Moon from is from the Moon itself. In a previous video that looked ahead to this year, I showed the view of the solar eclipse from the Moon, and it was interesting enough that I wanted to show it again. Unfortunately, there are no astronauts on the Moon at the moment, and even if there were, they would have to be on the side facing the Earth, and would probably need a telescope to get a good view. We don’t need to worry about how cold the lunar night would be, and to look at the Earth during the New Moon we would have to be experiencing lunar night. We’re going to look at a zoomed in view from the lunar equator facing the Earth, close to where Apollo 11 would have landed.

The dark spot made on the Earth by the Moons shadow is immediately obvious, especially looking at the Earth while the eclipse is at the close to the middle of totality, casting the dark shadow on the paler land of the Southern United States and Northern Mexico. When the eclipse begins, the shadow of the Moon creeps out from the boundary between daytime and night time, the dawn terminator, in the Pacific. The shadow then travels almost straight to the Southern part of North America, crossing under Baja California to make landfall in Mexico, before curving up towards the United States. The shadow continues diagonally up the continent, before beginning to turn Eastward as it approaches the Great Lakes. This Eastward path will take the umbra of the Moon out towards the Atlantic, before it collides with the dusk terminator. The shadow of the Moon moves against the direction of the Earths rotation, due to the motion of the Moon itself in orbit. Although the dark spot of the umbra is the most apparent, a close look will show the fainter greyish penumbra surrounding the umbra, places where a partial eclipse will be visible instead.

We might not get to see this eclipse from the Moon or from space, and only those few of us o be in the right place will get to see the eclipse at all. If you are in the path of totality, then I hope you get a good view. If not, then I hope you enjoyed the simulated version in my video or the description of it here. I will continue to show views like this, so you can see things that would otherwise be impossible to view. If you enjoyed this look, then you can subscribe to this website or the Caoimhín’s Content YouTube channel to stay up-to-date about events like this in future and get more these kinds of previews and special looks at astronomical events. Hopefully I’ll see you back here for the next one.