What's in the night sky in the week of 20 to 26 March, 2023 in our weekly stargazing guide. This week Mars and the crescent Moon make a lovely pair, while Mercury and Jupiter make their closest approach of the year.


Chris Bramley Hello and welcome to Star Diary, the podcast from the makers of BBC Sky at Nihgt Magazine. You can subscribe to the print edition of the magazine by visiting www.skyatnightmagazine.com or to a digital edition by visiting on iTunes or Google Play.

Ezzy Pearson Greetings, listeners, and welcome to Star Diary, A weekly guide to the best things to see in the Northern Hemisphere's night sky. As we are based here in the UK, all times are in BST. Do pay careful attention as the clocks have just changed, so make sure you have any conversions correct.

In this episode we'll be covering the coming week from 27 March to 2 April. I'm Ezzy Pearson, the magazine's features editor, and I'm here to take you through all of this week's stargazing highlights. So we start off on 27 March when Mercury and Jupiter are going to be making a very close approach to each other. Mercury is going to be -1.3 in magnitude. So still naked, eye visible, but a bit on the dimmer side. Well, Jupiter is going to be an incredibly bright +1.9 magnitude. So very bright there. One of the brightest things in the night sky, the two are going to be about 1.5 degrees apart on the western horizon. So that is about three times the diameter of the Moon apart for those two. They'll be up in the evening twilight just after sunset. Mercury is going to be setting at around about 8:20PM in the evening, so there won't be a lot of time to catch the two. So do try and get out there. You'll want to have a clear horizon because they are very low, very close to the horizon those two. The best way to find them is to wait until the Sun has completely gone down. Always make sure that the Sun has gone down when you are looking at these kinds of things. We want to make sure that you're not going to accidentally catch sight of the sun through your optics is that can really, really hurt your eyes. And once the sun's gone down, scan the low horizon with a pair of binoculars perhaps to help you. You, as I said, you can see with ease with your naked eye but a pair of binoculars will really help improve your views. And you should manage to find the pair of them down there on the western horizon. If you are having a bit of trouble finding them, there is going to be a much brighter object fairly nearby. And that is Venus. Venus is about +3.9 at the moment so incredibly bright. Definitely the brightest thing in the night sky after the Moon. And that is going to be quite a lot higher in the night sky than these two. But if you see Venus, if you look down towards the horizon a little bit to the right, you should see this pair nice and clearly. So that's a great opportunity to try and get to.

See those two. Then moving onto 27 to 29 March. Mars is going to be making some interesting close approaches throughout its journey across the sky. The best time to see Mars at the moment is probably going to be about 9:40 BST. That's when it's going to be highest in the night sky, but it will be around until about 3 a.m. That's when it's going to set. It's not the brightest planet at the moment. It's a magnitude+1.0. Mars is only going to be about six arc seconds across because Mars is beginning to move away from Earth at the moment. However, that is still clearly naked eye visible. You should be able to see it relatively easily in the night sky if you are looking for it. Now, on 27 March, it's going to be 8.2 degrees away from a 37% lit crescent moon. So that'll be quite a nice pairing together on the night sky. But Mars will also be close to what's known as the Shoe-Buckle cluster, or M35. I'm not 100% sure why it's called the shoe buckle cluster. Sometimes you find with these things, when you look at them through the eyepiece, they look completely different to how they are when you photograph them. And because they were named by people looking through the eyepiece, quite often when you look at a photograph in a book, which there is a lot more of the dim stars and the nebulosity and stuff that you can't see, even with a telescope, the names can seem a bit strange. But this one, it's the shoe buckle cluster and it is a +5.0 magnitude open cluster. And that's going to be around about 1.7 degrees away from Mars on the 27th. However, the trio is going to stay together through to the 28th of March. In fact, they'll be getting a little bit closer. The Moon will be slightly more lit up with 39% lit at that point, but it will only be 6.6 degrees away from Mars whilst M35 is only going to be 1.2 degrees slightly to the south of Mars. So that's a really good chance to try and get the trio together throughout the rest of the week. The Moon will then begin to pull away and move out across the sky, but Mars and M35 will stay together as a nice relatively close pairing through to the end of March. By April time, they're starting to drift away. Mars is starting to pull away, but you should be able to still capture them together. So if you are, perhaps because this will make a really nice photo opportunity. So if you are looking for that, if the weather's not cooperating you've got a couple of opportunities to capture Mars and M35 together if you want to get the Moon in that, you really need to be looking on 27 or 28. Really to see these you do want to be looking through a pair of binoculars or a wide field telescope. They are technically naked eye. At least the moon and Mars are but if you want to really appreciate them, and certainly if you want to get m35 in there you will need a pair of binoculars or telescope. Then finally, on 30 March, we have Venus and Uranus making their closest approach throughout the year. On that evening, Venus is going to sit about 1.2 degrees north of the planet Uranus. Now, there is going to be a significant difference in the brightness of these two. Venus is the brightest thing in the night sky after the Moon. It is a -3.9 magnitude at the moment so very, very bright, the kind of bright where you see it out of the corner of your eye and it catches your attention. Meanwhile, Uranus is magnitude +5.9, so that is right on the cusp of being naked, eye visible. There are some people who say that they can see Uranus with the naked eye, but you do need a very, very dark sky and you need to have incredibly good eyesight. You're probably not going to have much luck from the UK.

If you are looking for the pair though, grab a pair of binoculars and look out towards the Western horizon after the sun has set again. Make sure the sun has set fully because you want to make sure that you don't hurt your eyes.

Fortunately, in this case, there's no real rush because Venus and Uranus are very, very high in the sky at the moment. They'll be up for around about 3 hours after sunset. But to view them best, you're wanting to wait until it gets really dark when true, true darkness is set in. So perhaps wait about an hour after sunset to go looking for these two. However, if you are a bit impatient or you want to to get ready and get set up earlier. If you happen to be out around about 815 in the UK time, that is keep an eye out for something else that is going to briefly join the pair. And that is the International Space Station which will be passing a couple of degrees away. You will need to look up exactly what time it's going to appear overhead in your precise location. So, for instance, for us here in the studio in Bristol it's at 8:18PM that it's going to appear, but it'll be around about that time. So keep an eye out. Make sure you've got lots of time either side to make sure that you don't miss it. And again, that will be fairly bright in the night sky. I don't think it quite outshines Venus, but it does get fairly close. And if you would like a bit more guide on how to locate the ISS and find out exactly when it's going to be overhead, we have a guide to that over on our website www.skyatnightmagazine.com. I will put a link to that in the show notes for you all. But if weather or any other circumstance means that you can't see the pair, then there's another opportunity again on the 31st of March. This is actually when there are what's known as conjunction which means they have the same right ascension. Usually that's around about the same time when they have that closest approach on the night sky, but it's not always exact. So sometimes there's a bit of difference between when they are closest in the night sky and when they're actually in conjunction. And that is everything for the week of 27 March to 2 April. In summary: Mercury and Jupiter will appear together on 27 March, 27 to 28 March, Mars and the crescent moon will be close to open cluster M35 and throughout the rest of the week you can see Mars and M35 together as well. And finally, on the 30th of March, Venus and Uranus make their closest approach of the year. So thank you very much for joining us. Please do subscribe to the podcast to make sure you never miss another episode of Star Diary. And we hope to see you here again next week.

If you want to find out even more spectacular sites that will be gracing the night sky throughout the month, 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. 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 at Night Magazine. Goodbye.


Chris Thank you for listening to this episode of the Star Diary podcast from the makers of BBC Sky at Night magazine. For more of our podcasts, visit our website at skyatnightmagazine.com or head to iTunes or Spotify.


Elizabeth Pearson
Ezzy PearsonScience journalist

Ezzy Pearson is the Features Editor of BBC Sky at Night Magazine. Her first book about the history of robotic planetary landers is out now from The History Press.