Caoimhín's Content

Today we are going to be looking ahead to the night sky for the month of October. As always, my default perspective is from here in Ireland, and because I will be talking about the sky at night from here in Ireland, I won’t be dealing with the annular solar eclipse that is going to happen on October 2nd. There is this an annular solar eclipse this month but it’s not visible from Ireland and course it’s not visible at night-time, solar eclipses never are.

Starting at the beginning of October with the sky just after sunset, as early as 7:30. The night sky is going to continue to get darker earlier and earlier as we push from Autumn into Winter. We can still see the Summer Triangle, but it is already right above the South as early as 7:30. It won’t be with us all night long, so we’re definitely leaving summertime. Further westward in the sky, Arcturus is still visible early in the evening, but it’s getting lower in the sky, so you will need to go out earlier and earlier to catch that bright star. Saturn is going to be with us from sunset, as soon as the sky is dark enough for Saturn to emerge it will be visible. I was lucky enough to take a closer look at Saturn through a telescope quite recently, just at the end of September, and Saturn’s rings were still visible. It seems like they will still be visible, though noticeably quite thin, into October. Even through a telescope that’s not incredibly powerful, Saturn’s Rings are definitely visible. They are so thin that they almost look like little spike almost on either side. Thanks to the changing tilt of Saturn, we are going to see Saturn’s Rings thinner and thinner until they’re pretty much too thin to see over the next few months. Don’t worry, that will change again, Saturn’s tilt will continue to change until the rings are a little bit bigger and more visible again.

Moving on towards morning time, and focusing on the horizon to the East, as we move into October things will start rising earlier and earlier. Jupiter is visible by 9:30, nice and early in the evening. Of course, when the planet rises it will be close to the horizon. Regardless of the atmospheric extinction, when an object is that low to the horizon, especially when stargazing from a city, it is likely to be blocked out by terrestrial objects like buildings. Moving on to 11 o’clock and Jupiter is at a more reasonable height in the sky. It has also been joined by Mars, but at this time Mars is also quite low just after rising. If we wait a little bit longer, the planets will continue to rise. By 2 o’clock Mars and Jupiter are nice and prominent. Of course 2 o’clock in the morning, it is still late at night or very early in the morning depending on your perspective. By then, we will certainly have Orion and Gemini in the sky, you don’t have to wait until practically sunrise to see these planets and constellations anymore, as we did earlier in September. Unfortunately, as we move into October, Mercury is going to disappear from view, if it hasn’t already. When Mercury finally vanishes will depend on where you are, and light pollution from a city will certainly make Mercury very difficult to observe as we come to the end of September. By the time we’re into October there’s no sign of Mercury in the morning at all.

So far this has just been about the beginning of the month. If we move all the way forward to Halloween, then things will have changed significantly more. Comparing the very end of September to the very beginning of October, there won’t be a huge difference. As we progress through October, darkness will come earlier and earlier. We should be getting darkness as early as just 6:30 on the night of Halloween. Over the night of Halloween we of course move into November, so instead I’ll deal with the night before Halloween and we’ll move into the morning of Halloween after that. The sky the night before Halloween won’t look too different from the sky on Halloween. Beginning even earlier in the evening, so that there is a little bit of sunset glow, stars should be visible even from the city as early as 6 o’clock. It’s finally getting dark at a nice early time of the evening. You can have dinner, go outside, and start stargazing immediately. Depending of course on what time you have your dinner.

Right down at the horizon, Venus is just about visible. Venus is technically visible as the Sun sets over the course of October, but it is going to be quite difficult at certain times of the month. Venus is quite low by Halloween, though it is in a slightly better position to see earlier in October. It will stay quite low from here in Ireland, partly due to the angle at which we’re seeing the ecliptic. Just like Mercury in the morning in September, in other parts of the world Venus should be easier to see. Saturn’s nice and high even at 6 o’clock, and visible while there’s still a glow of sunlight in the sky. By the time the sky is truly dark, Saturn’s not quite at it’s highest, but it will be after another hour or so. Even before it reaches directly above South, it is quite high in the sky and above most buildings. The summer triangle is now noticeably past the South, it’s already hanging towards the Southwest even quite early in the evening. Pushing forward slowly to morning time to see how much earlier we can see those other planets rising. At just 8:15 Jupiter’s already up in the sky, though again it’s not particularly high. Waiting until a little later again and Mars will rise. Jumping from one end of the month to another, and it looks like Mars and Jupiter and further apart. This because Mars is still moving away from the Earth around the Sun, we still have to catch up to it before we see Mars move across the sky as we’d normally expect. Going out night by nigh the difference is a lot more subtle.

By the end of October, at just 11:30 rather than nearly 2 o’clock, Mars, Jupiter and Orion will be up in the sky. Push just a little bit further, coming up to midnight, and we’ve got all of Orion up in the sky along with Mars, Jupiter, Saturn, and of course Uranus and Neptune. The two more distant planets are out there as well, with Uranus near Jupiter by the Pleiades and Neptune closer to Saturn. Unfortunately they’re just not going to be visible to the naked eye. We’re finally starting to see a lot of planets closer to midnight rather than having to wait until morning time. You can still see a lot of the planets in the sky together, particularly if you have a binoculars or telescope for Uranus and Neptune. Coming all the way forward to sunrise let’s us see nearly New Moon at the end of October, at 6:30 in the morning. By then Mars will be after pretty much after reaching it’s highest in the sky. Both Mars and Jupiter will be high and easy to observe by the time the Sun is rising.

All of that was with the assumption of light pollution. If you are lucky enough to be in the countryside under dark skies, even more will be visible. Staying at the end of the month, at about 5:30 in the morning, the sky will still be pristinely dark. You do have to get up quite early for that, but you don’t have to get up at 4 o’clock in the morning as you might have had to do during the summer. Mars and Jupiter will already be quite high in the sky by then which makes them that bit easier to observe. This also puts Uranus in a good position, still just on the other side of the Pleiades from Jupiter. With dark enough skies, there will of course be a glow from the Milky Way in the background. As we’re getting into winter time however, especially in the morning, it is that outer limb of the Milky Way that we’re seeing. This portion is out behind the famous constellations Cassiopeia and Perseus, with Cassiopeia forming a W shape and Perseus as a sort of fin shape. The core of the Milky Way is on the opposite side of the galaxy. That brighter core is going to get less and less visible as we move into winter. I mentioned this during the summer, and I’ll mention it again when we’re further into winter. As we’re coming into winter we can see that the core of the Milky Way is getting less and less visible, it’s setting while that glow of sunset is still leaving the sky. Soon, within a couple of months, it will be directly behind the Sun. As the Sun sets, Scorpius is already almost entirely below the horizon, and even Sagittarius isn’t fully visible at just 6:30. While the summer triangle helps you find one of the Milky Ways arms, it is Sagittarius and Scorpius that are most useful for finding the core in the Northern Hemisphere. As we are dealing with the countryside, more stars will be visible even as the Sun goes down. Venus will seem brighter and clearer without the glow of light pollution to obscure it. Sagittarius is at least visible in part, but there’s too much of that sunset glow in the sky for us to see the glow of the Milky Way. Although we are going to get those longer, darker nights now as we come into wintertime, unfortunately our position around the Sun relative to the core of the Milky Way, it’s just the wrong way round. We’re just not going to get that good of a view.

Meteor showers look their best out in the countryside, and there are a few running during October, although they minor ones. Despite the meteor showers that we’re getting over the course of October being mostly quite minor, they’re not going to be as big as the Leonids or the Perseids, they’re is at least a bunch of them. A lot of minor meteor showers will increase the amount of the meteors that we can see in the sky, if only by a little. Taking a look close to the middle night will bring a lot of the meteor shower radiants above the horizon, be meteors radiating from a certain location can be seen even if that point in the sky isn’t visible itself. The Orionids are coming up in October, with their peak on the 21st. They can get up to about 20 meteors across the zenith an hour, or 20 ZHR, which migh tmake them more medium than minor. There will almost always be about 10 or so meteors falling through the sky an hour, coming from the antihelion and other background radiants. You can check out some of my previous posts on this website to learn more about those. We can see the Northern Taurids during October, though they are not peaking until November. The Andromedids, also not peaking until November, are ongoing through Ocotober, so they may still contribute a few extra meteors to the sky. Continuing to move back through the month we can see the Eta Geminids popping up as well. This is around the night of the Full Moon, the light of which will of course block out some of the fainter meteors. The Eta Geminids will be peaking on the 18th of October, but it’s maxing out at about 3 ZHR even at that peak. The October Delta Aurigids will be peaking even earlier, on the 11th of October, but at a peak of about 2 meteors an hour. Some of these meteor showers just won’t be great. Although we have a good few of these meteor showers going on in October, there won’t really be that many shooting stars over all. Taking a look at the Southern Taurids they vary from about 5 to 10 ZHR, though they’re not peaking until the 5th of November. There are also the September Eta Perseids, they peaked in September but a few meteors from that parent body may make their way into the sky in October as well. The range of a meteor shower outside its peak may contribute very few meteors, but they do still add one or two occasionally.

Moving on to the night of the Full Moon, unlike the 100% Full Moon in September, it looks like 99.6% is around the maximum we’re going to get here in Ireland. Looking at the distance from us to the Moon, and it’s just 353,535 kilometers. Taht’s certainly close enough to make this a Supermoon. Not only that, but the Full Moon that we’re getting in October, on the 17th, is a little bit more super than the one we had in September. The October Supermoon is almost 10,000 km closer than the Supermoon that we had in September, which was about 362,000 kilometers away. Of course, that Supermoon that we had in September had a partial lunar eclipse, whereas this Supermoon that we’re getting in October will not. It just so happens that for October, September and August, all three of those Full Moons were within the range of distances to be classified as Supermoons. You may have noticed the Full Moon being described as a Supermoon a few times recently. this is partly thanks to the big range of distances involved. Whether the Moon is 360,000 kilometers away or 350,000 kilometers away, they’re both a lot closer to us than the potential maximum of about 400,000 kilometers away. Thanks to this range, very often you will get a couple of Supermoons in a row, it seems like 3 in a row this time at least. The Full Moon in November could be pretty close as well, but we will have to wait and see.

I will certainly look ahead to the November Full Moon late in October. If you would like to catch that future article, you are more likely to catch it if you subscribe to this website, and you can catch the associated YouTube video by subscribing there. If you enjoyed this look ahead to the night sky in October then make sure you like this article as well. Hopefully , I’ll see you back here next time.