Caoimhín's Content

As we approach the end of April, the sky has continued to shift and change, so we will be taking a look at what is visible where now, as the nights begin to shorten. We will also take a look brief look at the Lyrid meteor show that occurs at the end of April. Back at the end of March, in the video looking ahead to the month of April, I skated over this particular shower, and it certainly hasn’t gotten it’s own dedicated video, for good reason. Luckily, there will be another meteor shower coming up soon, but we’ll get to the meteor showers after a more general look at the sky.

As we are certainly getting into summer, real darkness won’t begin until after 10 o’clock, looking at the sky at 10 exactly we can still see a little bit of light creeping over the western horizon. By late April, Orion’s belt is barely over the horizon as the Sun sets, soon to leave our sky for a while. Leo is nice and high to the South much earlier than midnight now, making it even easier to catch, and we’ve still got Gemini, a little further West but high above Orion. Virgo is now covering a very large portion of the Southeastern sky, but it can still be tough to see. The only star in Virgo that is easily visible in the city is Spica. There is a little rhyme or mnemonic device that you can use to help you find it, “Arc to Arcturus, Spike on to Spica”. Start by finding the Big Dipper or The Plough. The handle of the Plough or the Big Dipper, the Tail of Ursa Major, has a curve, or an arc to it. If you follow the arc away from the Plough, it will lead you to Arcturus. One of the brightest stars, with a distinctive reddish hue, Arcturus is a prominent star in the constellation of Boötes. Boötes is not the most famous, though it’s outline is a bit more visible than Virgo’s, it still isn’t one of the more culturally significant constellations. All the same, Arcturus is nice and clear, if you arc to Arcturus you can spike on to Spica. You need to curve to Arcturus, but then proceed onwards in a straight line. This time of the year, that means making a line down and towards the South and Westward of Arcturus. Spica is one of the brighter stars as well and certainly the brightest in Virgo. The Full Moon will be right next to Spica this month, pretty much the brightest thing close to the Moon even a day before or after its fullest. Moving through to morning time, the Full Moon will only set as the Sun is rising, another way we can tell that we’re close to the Full Moon. Just before the Sun rises, Saturn will be up, but it is going to be very tough to spot especially in the city. The constellation of Scorpius is now a little bit more prominent, it’s up high a little bit earlier before the sunrise, giving us more time to observe it in a good level of darkness. We can also see parts of Sagittarius, now a good distance from the sunrise.

Moving onto the meteor showers, labelling their radiant points in the, we’ll see the Antihelion point just by the Full Moon. The Antihelion is the point in the sky opposite to the Sun, so the Full Moon will always be very close to it. We tend to have meteors falling into the sky from there all of the time, without being associated with a particular comet, asteroid or other object. The Antihelion meteors are part of the more or less constant background rate of meteors, something I delve into in greater detail in a previous video. Higher in the sky, unsurprisingly in Lyra, we see the April Lyrids. They are variable meteor shower, with some years being far greater than others. Despite being a pretty good meteor shower even on off peak years, this year it happens to be peaking right around the Full or nearly Full Moon. The extra light in the sky is gong to block out some of the fainter meteors, and there will be no part of the night without the Moon or some twilight glow.

Meteor showers are caused by trails of dust and small particles crossing the Earths orbit, left behind by comets or asteroids. In the case of the April Lyrids, the comet C/1861 G1 Thatcher is the cause. There is no P in its name, despite being a recurring comet, as it’s period is around 420 years, making it a very rare visitor. It is a long period comet, and actually one of the shorter period ones of the group, which can have orbital periods of a thousand years. Peaking early next month are the Eta Aquariids, caused by a trail left by Halley’s comet. Comet 1P/Halley, one of the most famous comets. It is a periodical comet with a far more reasonable orbital period of just under 80 years, it should be back around 2061. The Eta Aquariids maximum is around the 5th of May this year, usually around the 5th or 6th of May depending on the year. Although the Eta Aquariids may not be as bright as a good April Lyrid shower if all things were equal, this year they are not equal, as the Eta Aquariids occur when the Moon is practically new. This will make them a bit easier to see. This meteor shower radiates, of course, from Aquarius, which is just after reappearing from behind the Sun. For most of the night, the radiant will be below the horizon, but that’s okay. Meteors associated with a certain radiant can still appear almost anywhere in the sky, but their path or tail will originate from the radiant, if you were to trace it back.

The Eta Aquariids are often written as η-Aquariids, with a symbol at the front looking a little n, but with a long descender as its second leg. That is the Greek letter eta, which is normally pronounced like an “i” in Modern Greek, almost like the long “ee” sound in English. We often need to keep track of which Lyrid or which Aquariid meteor shower we’re talking about, as one constellation may play host to many over the course of the year. The April Lyrids, of course occur in April, and you could probably call the Eta Aquariids the May Aquariids if you wanted to, but different schemas name these things in slightly different ways. The radiant of the Eta Aquariids is very close to the star Eta Aquarii, one of the brighter, but not brightest, stars in Aquarius. Out in the countryside meteors are going to be a lot more visible, light pollution will not only hide fainter meteors, it will make the bright ones harder to spot as well. Out in the countryside, if we take a look to the early evening sky again, Leo is certainly a lot more defined, it’s brightest stars standing out from the crowd of stars visible in dark skies. Spica continues to be noticeably bright, and the other stars in Virgo are certainly visible, but this doesn’t really help. The stars in Virgo never really look like a young woman, even with the lines drawing them together it remains a pretty abstract shape. With Leo at least, it kind of looks like a profile outline of a lion laying down, almost like you might see in a children’s “join-the-dots”, book. Moving towards the morning out in the countryside, normally we would get to see the milky way, but the Moon will be very close to the Milky Way when it’s full, and right on top of it when it’s a little past full. Poor weather conditions of course can block out the Milky Way as well, just like they block out everything else, it’s certainly worth accounting for when you are looking for the aforementioned meteor showers. As we move into May and the Moon moves into its new phase, the Milky Way appears in between Sagittarius and Scorpius. I think it’s worth repeating that as we come up to summertime, we’ll get to see the lovely glow of the Milky Way earlier and free from the glow of sunrise, but of course we’ll have a little bit of twilight in the sky once we reach midsummer all night long here in Ireland. The night also gets significantly shorter. Closer to the Equator, midsummer will be an even better time to look for the Milky Way.

For the coming few days, as the Moon and sunrise obscure the Milky Way, we can definitely see Scorpius and Sagittarius, as well as the summer triangle, so we know that the Milky Way is there even if we’re not going to be able to see it. I mentioned in a previous video that Mars and Saturn will start to be visible in the morning, at least if you are in the countryside. They are still going to be very tricky, Saturn is getting reasonably high, but only as the Sun’s light brightens the sky as well. Mars is still low to the horizon, and closer to the Sun in the sky than Saturn. The previous Irish language video (with English subtitles) goes into more detail on the motion of the planets. We can see over the course of the night that the summer triangle comes into our sky quite early, but it isn’t fully above the horizon by 10 o’clock or so when the sunsets. Then again, we’re not in summer so that makes sense. However the summer triangle is fully above the horizon by just 1:15, and it will stick with us till the Sun’s light wipes it out, around 5:45. With the triangle with us most of the night, we have another sign that we are approaching the summer.

By removing any landscape and getting a clear look at the horizon, we can see Jupiter very low in the sky. If you have a clear enough horizon, Jupiter is bright enough to stand out against the glow of sunset even in the city, but it is extremely low. If you’re at the West coast of any landmass, able to look Westward with no land to obscure your view, you’ll have a better chance to catch it. The coast of an ocean or sea will certainly do the trick, as will a large enough lake. The Great Lakes and other large lakes are big enough that you can’t see land on the other side thanks to the Earths curvature, all of the horizon is water.

Next time, we’re going to take a look at May and what we’ll see over the course of the month. If you’d like to make sure that you catch that video or article, and get more information about the upcoming Eta Aquariids, make sure you subscribe to this website or my YouTube channel so you are more likely to be notified when it comes out Thursday. I hope you get a chance to see some meteors soon, and hopefully I will see you back here next time.