Two comets make their way across the night sky, a full Moon and Mercury is up in the evening sky in this week’s stargazing podcast, Star Diary 25 to 31 March 2024
Chris: Hello and welcome to Star Diary, the podcast from the makers of BBC Sky at Night Magazine. You can subscribe to the digital edition of the magazine by visiting iTunes, Google Play, or Apple News, or to the print edition by visiting www.skyatnightmagazine.com.
Ezzy: Greetings, listeners, and welcome to Star Diary, a weekly guide to the best things to see in the northern hemisphere’s night sky. In this episode, we’ll be covering the coming week from 25 to 31 March. I’m Ezzy Pearson, the magazine’s Features Editor, and I’m joined today by Katrin Raynor.
Katrin is an astronomy writer and astronomer who is joining our team of presenters for the first time. So, Katrin, welcome to the show.
Katrin: Hello, Ezzy, and thank you very much for having me. It’s exciting.
Ezzy: So, would you like to introduce yourself to our audience out there so they can know who it is that they are listening to?
Katrin: Absolutely, thank you. Yep, so I’m an amateur astronomer and when the sky is clear I enjoy going outside, naked eye stargazing, or using my 6-inch Dobsonian telescope. I’m a Fellow of the Royal Astronomical Society, Royal Geographical Society, and I’m a member of the Astro Space Stamp Society. I enjoy collecting astronomy themed stamps.
And I regularly contribute to the Yearbook of Astronomy. I write for the Sky at Night and Gibbon Stamp Monthly and I have asteroid 446500 named after me, so my claim to fame there.
Ezzy: Yeah, I think that’s the one that I’m always the most excited about is you’ve got an asteroid named after you. How did that one come about?
Katrin: Yes, it was a real honour and a real surprise.
I was actually nominated by a friend of mine and he put my name forward. I think it’s decided by the International Astronomical Union.
Ezzy: Yes, that sounds like the sort of thing they’d do.
Katrin: So he put my name forward with a short description. It was actually Alan Hale of Comet Hale-Bopp fame who emailed me and he must have had the, it’s kind of like, well not a newsletter, but like an announcement of who’d had asteroids named after them.
They contacted me because we’d been doing some interviews together for a previous radio show during lockdown and he said, “Oh, I’ve just seen your name. Congratulations.” Oh, wow. I was like, I didn’t even know it was out. So yeah, that was a real honor, a real surprise.
Ezzy: There was a lot of asteroids out there and it’s always better to have something that has a name than to call it like XQ3P457 or however it is that they do these things.
Katrin: Yeah, like some of the planets that they’re discovering, they just have these crazy long names. I can’t even remember what they are, but yeah.
Ezzy: You don’t.
Katrin: Give it a name.
Ezzy: On to today’s show, where in a minute we’ll go through everything that’s coming up in the week’s sky. Now normally at the top of the show I say as we’re based in the UK all times are going to be in GMT but that’s not strictly true in this episode because, here in the UK at least, the clocks are going to change on 31 March in the early hours of the morning so while most of the times are going to be in GMT some of them will be in BST.
We will try and make it clear which one is which but assume it’s GMT unless otherwise stated. But with that piece of admin out of the way, Katrin, please do tell us what we have coming up for us in this week’s Night Sky.
Katrin: Okay, well, it’s a fairly quiet week ahead with the main highlights being a full Moon and a nice celestial pairing between the Moon and a binary star.
We have two comets hanging around. We have Comet C/2021 S3 PanSTARRS and Comet 12P Pons-Brooks to enjoy.
But this week I’m going to start off with the Moon. So on 25 March we have a full Moon and a penumbral lunar eclipse, which starts at 4:53AM UT and ends at 9:32AM UT.
So for those that don’t know, a penumbral lunar eclipse occurs when the Moon travels only through the outer, fainter part of the Earth’s shadow, or penumbra, and this happens when the Earth moves between the Sun and Moon. But the three do not form a perfectly straight line.
And these types of eclipses are quite easy to miss because the Moon’s surface only darkens very slightly.
So with that in mind, you know, unfortunately it’s not going to be a spectacular event, as there won’t be any noticeable changes to the Moon with the naked eye and the Moon will set below the horizon before maximum eclipse.
But for those wondering when the next total lunar eclipse is, well we have a while yet to wait for one. The next one we will see from the UK is 7 September 2025. I think I’ve only ever seen one total lunar eclipse and that was back in 2015, so I look forward to next year.
Ezzy: I’ve seen one when I was very young, I have no idea when it was, but it’s one of those things I’ve always wanted to see again.
Unfortunately, clouds do what clouds gonna do. And so the last couple of times I’ve been able to, or there’s been one happening, it hasn’t. Which is annoying.
Katrin: Yeah, the joys of living in the UK.
Ezzy: Yeah. We should also say that in terms of other eclipse news, there is a big total eclipse that will be coming up in a couple of weeks on 8 April.
So do keep your ears peeled for that, and we will have more details about that in our April 8th episode.
Katrin: So, the following day on 26 March, if you look to the southeast at around 9:00PM you will see Spica, or Alpha Virginis, which is the brightest star in the constellation of Virgo, extremely close to the Moon. And they’re going to be just over one degree apart.
So, Spica is very bright, it shines at a magnitude of around +1.0, and is the 15th brightest star in the sky. And when we look at Spica, you know, we see one star, but in fact it is two. And it looks distinctly blue-white in colour, and the pair of stars are both hotter and larger than our Sun.
But unfortunately, even with an optical aid such as a telescope, you can’t actually distinguish or see the two separate stars. Only the analysis of its light with a spectroscope reveals the dual nature of the star.
But it’s going to be a lovely coupling in the sky to enjoy. You know, I always think it’s really magical when a planet or a bright star sits really near to the Moon, especially Venus, and I love seeing Venus or Jupiter shining brightly next to the Moon, especially at Christmas time.
I think it’s a lovely seasonal thing to see.
Ezzy: It is one of those things that always stands out to me when you’re walking home from work or something and the Moon is up in the night sky and then you see like a bright star or as you say, a planet next to the Moon. It’s one of those things that definitely catches your eye and draws you to it.
Katrin: Yeah, it’s fantastic to see. I do really enjoy seeing those conjunction, I suppose.
So whilst you’re outside looking at the Moon and the constellation of Virgo, try and locate the large semi circular asterism called the bowl of Virgo, which is formed by five stars of the Virgo constellation.
Now this is a very rough guide on how to find it, and I would recommend using a star chart or app to help you.
So once you’ve found Spica, cast your eyes in a line, upwards and slightly to the right from speaker, until your eyes rest on the next closest brightest star called Porrima. And once you’ve found Porrima, you have found one of the bottom corners of the bowl, if you like. And from Porrima, a line of stars extends diagonally outwards to the left, and to the right, which form the sides of the bowl.
But big disclaimer here, it’s going to be a challenge locating the bowl unless you are in an area with darker skies, and of course, you know, it’s an almost full Moon, it’s not going to be 97% illuminated, it may wash the asterism out, but give it a go, and get to know your way around Virgo if you can, because when the Moon is out of the way next week, I will tell you how to view the Realm of Galaxies in this region of the sky.
Ezzy: I should also say that if people are looking to find the bowl of Virgo, then we do have guides on how you can go about doing that over on our website, skyatnightmagazine.com, and I will put a link down to them in the show notes below, so you can find them nice and easily as well.
Katrin: So a full Moon can wash out any fainter asterisms, as I’ve just mentioned, you know, deep sky objects may be hard to find, comets and stars totally washed out, and a full Moon can be a real thorn in astronomers sides.
But if you are interested in learning more about the moon, or just getting some observing time under your belt, a full Moon can bring a lot of pleasure. There is so much to see and explore with your naked eye, or optical aids. You can see craters, seas or maria, and mountain ranges, and you can spot the Apollo landing sites.
Ezzy: There’s always lots of interesting things to see on the Moon.
Katrin: Oh yeah, loads, isn’t there? And then, you know, a lot of people do complain that, oh, it’s a full Moon, you know, I want to be outside my telescope looking at nebulas and open star clusters.
But I love seeing a full Moon. I really, really enjoy it.
Ezzy: And it’s one of those things that’s very easy and it’s very accessible and it’s the first thing that a lot of people recognise in the night sky.
Katrin: And I think if you are just starting out in astronomy as well, it’s a really good place to start, isn’t it? Because you can see so much more.
You don’t need to like use a star chart or an app to find it because you just look up and it’s there shining brightly. So when I’m looking at the full Moon or the Moon in any of its phases really, you know, I might just use my naked eye or a pair of binoculars. I actually bought a monoscope from a supermarket for around £40 and it’s been brilliant for looking at the Moon. And it requires minimal effort to set up in the garden.
And also I think, you know, you are getting your astronomy fix as well, so with the weather in the UK you just kind of have to make the most of the clear skies and anything that you can see in it.
Ezzy: Absolutely.
Katrin: Moving on to the Solar System now. As March comes to an end, we’re going to close the month with a couple of cosmic comets.
But before that, I would like to mention Mercury. Mercury is difficult to observe from Earth because it always appears too close to the Sun. You know, it’s rising and setting together with the Sun. However, the best time to see Mercury this month will be 25 March, when it sets two hours after the Sun in the West.
It will be around magnitude +0.1, but should still be fairly easy to see in the evening sky. And you know what I think, out of my whole time observing, I’ve only ever managed to spot Mercury once. It is notoriously difficult, so I don’t know if that’s my eyesight or I just wasn’t looking hard enough, but I mean, it’s tricky.
Ezzy: Yeah, trying to find something that close to the Sun, it’s never going to be easy.
Katrin: No, not at all. I remember being out once with a group of friends on the top of a valley and they were like, yeah, look, there’s Mercury. You can see it. And it literally took me so long to actually manage to locate it. But you know, it was great.
It was good. I was so happy that I managed to spot Mercury that evening. So I actually haven’t forgotten it and that was a long time ago. It made an impact.
So throughout March, Comet C2021 S3 PanSTARRS has been an observing target for astronomers. We all love a comet, you know, we don’t see them that often and we just don’t know what they’re going to do.
They are very unpredictable, just like the British weather. But later on this week, Comet PanSTARRS will cross the Coathanger Cluster, which is an asterism in the constellation of Vulpecula the Fox. Now the Coathanger is an open star cluster, so in fact it’s a really good opportunity to view an open star cluster and a comet.
So you’re really killing two birds with one stone, and on 31 March the comet’s crossing will happen at around 3AM BST in the eastern sky. You’re going to need a pair of binoculars to view the comet, as it’s not quite at naked eye brightness yet. So, I haven’t actually had the opportunity to view PanSTARRS at all because the weather’s just been so terrible here.
Ezzy: Yeah, I’m not in the best place to be looking for dim comets at the moment, I have to say, because I live in the middle of the city, which is always very distressing when you’re talking about it. I get told all about all these wonderful stargazing sights coming up and I can’t see any of them unless I go out of the city.
Katrin: You’ll have to come to South Wales.
Ezzy: Yes, I think that’s one of the reasons why I like the Moon because it’s one of the things that you can see pretty much wherever you are.
Katrin: Absolutely. It’s always visible in a city, isn’t it? Yeah. One
Ezzy: of the things you did mention there was the Coathanger cluster. A couple of weeks ago with Mary, I was talking about how so often there’s these asterisms or constellations which have… called names which look nothing like what they actually look like, but the coat hanger looks like a coathanger.
Katrin: It does.
Ezzy: Like if you see a set of stars in the shape of a coat hanger, that’s it.
Katrin: You’ve got it. You found it. Yeah.
You know, I agree. I mean, a bit like constellations, isn’t it? You know, they have all these names and you just think, well, it doesn’t look like a fox or the twins or anything, you know, you have to use your imagination, don’t you?
Absolutely. So we’re going to move on to another comet now, which I’m sure you’ve all heard about, Comet Pons-Brooks. On 27 March it just clips the corner of the Triangulum constellation as it makes its way towards the constellation of Aries in the west northwestern sky. Which leads me on to then 31 March at midnight BST.
Ponds Brooks lies less than 0.5 degree from Hamal, a bright star in Aries. So if you locate Jupiter in the west northwestern sky, this is going to help you locate Aries. But however, you know, as we approach the end of the month, the longer, brighter evenings will be problematic for viewing dimmer objects, and you will need a pair of binoculars to view Pons-Brooks as well.
Ezzy: Definitely. I think also with comets, if you can get the chance to go out and see them because they are so unpredictable and you don’t know when the next one’s going to come. Well, we know when some of the next ones are going to come, but like the long period ones, they just show up. So do try and get out there and see them if you can.
Katrin: And you don’t know how long they’re gonna hang around for either, that’s the other thing, isn’t it?
Ezzy: No. Sometimes they can go through perihelion, their closest approach to the Sun, and just the heat of the Sun just breaks them apart, and we never see them again. So, catch them while you can.
Katrin: So, on 31 March, whilst you’re out looking at Pons-Brooks, take this opportunity to enjoy a few deep-sky objects which lie in the constellation of Taurus the Bull, which is close to the constellation of Aries and of course the comet.
So, locate Taurus to the upper left of Aries. Taurus hosts two fantastic naked eye open star clusters. So Aldebaran, the eye of the bull, a red giant, is positioned within one of these star clusters. And to find Aldebaran, it’s quite simple. Just look for a visibly orange star, which I have, on occasion, when Mars has been in the night sky, confused the two.
Ezzy: It’s easily done.
Katrin: Yeah, but you should then be able to make out a clear V shaped pattern of stars lying on its side. And this cluster is called the Hyades. And then located an almost straight line to the right, there’s another open star cluster called the Pleiades or M45, commonly known as the Seven Sisters because of the seven stars that you can see.
Ezzy: There are various challenges that people do as like, how many stars in the Seven Sisters can you actually see with the naked eye? Which is a test of both how dark your skies are and how good your eyesight is. Again, we have a guide on that on our website. If people want to challenge themselves and see how many they can see.
Katrin: Yeah, it’s tricky again. I think it’s just my eyesight’s terrible because I’m pretty sure I can never see seven stars.
Ezzy: Yeah, just have to keep looking, keep searching and maybe you’ll convince yourselves you can see them one day.
Katrin: Yeah, just fill in the blanks. But yeah, I mean, generally I’d look at Pleiades through binoculars or the monoscope that I mentioned when I can’t lug out my Dobsonian telescope because it’s very heavy.
So yeah, something lighter and the binoculars, they do a good job.
Ezzy: Well, sounds like there’s lots of interesting things to see in the night sky this week, so thank you very much for taking us through all of those, Katrin.
And if at home you would like to keep up to date with all of the latest stargazing highlights, do be sure to subscribe to the Star Diary podcast and we’ll hopefully see you back here next week.
But to go through all of those again, we’re going to start off with the Moon this week and there will be a penumbral eclipse of the Moon on 25 March.
Then on 26 March, the star Spica is going to be close to the Moon near the bowl of Virgo, so definitely look out for those as well.
Then in terms of the Solar System, Mercury is going to be in the sky throughout the week, but is probably best viewed at the end of 25 March.
We also have two comets which are making their way across the night sky, have been for several weeks so far. Comet S3 Pan STARRS will be visible throughout the week, but on 29 March, it will be going past the Coathanger cluster.
And Pons-Brooks will be 0.5 degree away from the star Hamal in Aries on 31st as well.
Whilst you’re out looking at Pons-Brooks, you might also want to take some time to admire Taurus the Bull, and perhaps the Pleiades as well. So lots of things there to look for in the night sky, and we will hopefully see you all back here next week. Goodbye!
If you want to find out even more spectacular sights that will be gracing the night sky this month, then Be sure to pick up a copy of BBC Sky at Night Magazine, where we have a 16 page pull out sky guide with a full overview of everything worth looking up for throughout the whole month.
Whether you like to look at the Moon, the planets, or the deep sky, whether you use binoculars, telescopes, or neither, our Sky Guide has got you covered, with detailed star charts to help you track your way across the night sky.
From all of us here at BBC Sky Night Magazine, goodbye.
Chris: Thank you for listening to this episode of the Star Diary podcast from the makers of BBC Sky Night Magazine, which was edited by Lewis Dodge.
For more of our podcasts, visit our website at skyatnightmagazine.com/podcasts, or head to Spotify, iTunes, or your favourite podcast player.