Caoimhín's Content

Today, we will be looking at the sky for the second half of the month of October and we’re going to start in the morning, rather than at sunset as we usually do.

Looking at the sky in the southeast before sunrise on the 17th, the planets Jupiter and Venus are prominently visible. It is easy enough to see Orion or An Bodach due south, and higher to the southwest are the Seven Sisters or the Pleiades. If we push ahead a little later in the month, we’ll be able to see that the Moon and Venus come very close together as the sun rises. They are going to get closer as they come up during the day, but we’re not going to see the Moon going in front of Venus. The Moon isn’t going to occult Venus this month, and we wouldn’t be able to see it during the day anyway.

Coming back towards sunset, there is a lot to see this month, but the majority of the very interesting things are meteor showers and comets. Most of those things are a little faint, they either aren’t easy to see with the naked eye, you need to use a binoculars to see the comets, or for the meteor showers it is much better to be out in the countryside. Even in the city, we’re able to see the planet Saturn, it is still with us for almost the whole night. The planet Saturn is after passing its point of opposition already, and for that reason, the planet will be going down before the Sun comes up in the morning. The planet won’t be with us for the whole night, but the majority of it and certainly the beginning of the night. We are going to push out to the countryside, because the countryside is the best place to look at the meteor showers and the comets that are coming out at the end of the month.

We don’t have to wait until the very end of the month to look at the comets. Over in the direction of the Plough there’s one already visible. We’re looking under the Handle of the Plough for Cor Caroli, one of the brightest stars that is right under the Plough’s Handle. Around the 16th and 17th of this month, the comet C/2025 A6 Lemmon is going across this part of the sky. Zooming in on this area out in the countryside, we’re able to see a couple of other galaxies outside of our own. Just around Cor Caroli are the Croc’s Eye Galaxy also known as M94, and the Waterbug Galaxy. Zooming in on the comet, it is pretty faint and a bit hard to see. It’s not a very bright object, just around magnitude 10 or 10.5, which isn’t very very bright. The comet is getting brighter as we push ahead in the month, but also the comet will be pushing out of this part of the sky that is around the north star.

Anything that is close enough to the north star in the sky isn’t going to go under the horizon, making it circumpolar. Even when the comet is very close to the ground it won’t be under the ground, the comet is still in the sky. If we remove the trees and everything in the way, moving to a perfectly smooth horizon, we can see that even when the comet is at its lowest point in the sky it is still above the ground. So close to the ground, you have to look through plenty of atmosphere to look at the comet, and for that reason the comet won’t look as bright. The comet isn’t going to look like something that is magnitude 10, it’s going to be closer to 14, and that’s harder to see. When the comet comes higher in the sky, the problem isn’t as bad. The Moon is there in the morning on the 16th and 17th, but if we push ahead a few more days the Moon will be out of the way.

For stuff like this, things that are hard to see, it is important to make sure that the Moon won’t be in the the way when you are looking for them. Looking for the meteor showers, it’s the same. There are a few showers going on at the end on the month, but the most important one that is coming up is the Orionids. The peak for this meteor shower will be on the 21st of this month, so after pushing ahead to the right day we can see, maybe 18, maybe as low as 4 meteors per hour. The maximum is up to about a 20 ZHR. There are a couple of other meteor showers ongoing, but the other one that was pretty good this month was the Draconids. We’re too late now to see them now, their peak was around the 8th day of this month and they were completely over before the 10th. The Draconids are finished but the Orionids are still to come, and usually the Orionids are a little bit better, especially when the Moon is out of the way, which it will be.

Coming back to the Sun setting, to the beginning of the night, we’re after looking at one comet already, but there is another comet after coming into or solar system, 3I/ATLAS. This comet is after coming into the solar system from outside the solar system. This comet isn’t a member of our solar system at all. Looking at the 21st day of this month, it’s almost directly on the wrong side of the Sun for us to see it. If we come back a little bit closer to the middle of the month the comet is still too close to the ground as the Sun sets. If we go ahead a little bit, to the end of the month, the comet will come around the other side of the Sun. Then the comet will be up in the morning and close enough to Venus. If we come to Halloween, it’s very close to Venus in the sky, but this comet isn’t even as bright as the other comet A6 Lemmon. Looking at this comet, its magnitude is around 13.98, almost 14, and so low in the sky that that’s up to 15.25 or so. This comet is very very hard to see, but also it is something sort of rare. Things don’t seem to come into our solar system often. There are only 3 things confirmed to be interstellar so far, hence 3I/ATLAS, 3I for the third interstellar object that’s after coming into our solar system. There’s a chance that things come into our solar system more often, and we’re only after seeing 3 of them so far. However, the popular theory currently is that these interstellar visitors, at least those that come through the inner solar system, are something sort of rare. Normally, the majority of the comets and everything that we see in our solar system, they are from our solar system, but with these few interstellar objects, there are things after coming into our solar system from outside.

If we are looking at the end of the month, on the 23rd, down towards sunset with the atmosphere off, we’re able to see Mercury and Mars. They are both above the horizon while the Sun is setting, but from our point of view here in Ireland, they aren’t far enough from the Sun in the sky and they aren’t high enough from the ground for us to see. If we go somewhere different, down to the equator, we’ll have a better view. From low latitudes, the planets and the Moon are a lot higher in the sky. They are still the same distance from the Sun but they are higher off the ground, and the Sun is going down under the horizon in almost a straight line. For these reasons they’re still up while the sky is dark.

That’s something that we won’t be able to see from our location here in Ireland, but it is nice to know that it’s happening. We know, even if we’re not able to see it, that those three objects, the Moon, Mars and Mercury, will be next to each other on the 23rd of the month. While we are out in the countryside, we’re able to see that Uranus is still next to the Pleiades. That’s something else that you need to use a binoculars in order to look at. There are a couple of interesting things happening and coming up still in the second half of October, but for the meteor showers and the comets, it is much better to go out to the countryside to see them. For things like the comets and the planet Uranus, they will look better if you have a binoculars or something else to help you. You don’t need to use that to look at the Moon next to Venus at sunrise, you’ll be able to do that with your naked eye.

That’s a little bit about the sky that is still coming up this month, I hope that you enjoyed reading it. If you did enjoy, then make sure you like it and also if you are interested in this topic then make sure you subscribe to this website and my YouTube channel. Thank you very much for reading and hopefully I’ll see you back again.