Keep an eye out for the three innermost planets Mercury, Venus and Mars just after sunset in this week’s stargazing guide.
What’s in the night sky in the week of 17 to 23 July, 2023 in our weekly stargazing guide. Keep an eye out for the three innermost planets just after sunset in this week’s stargazing guide.
Chris Bramley Hello and welcome to Star Diary, the podcast from the makers of BBC Sky at Night Magazine. You can subscribe to the print edition of the magazine by visiting www.skyatnightmagazine.com or digital edition by visiting on iTunes or Google Play.
Ezzy Greetings listeners, and welcome to Star Diary. A weekly guide to the best things to see in the northern hemispheres night sky, as we are based here in the uk all times are in BST. In this episode, we’ll be covering the coming week from 24th to 30th of July. I’m feature’s editor Ezzy Pearson and I’m joined this week by reviews editor Paul Money. Hello Paul.
Paul Hello, Ezzy, another week to look forward to.
Ezzy Yes. So what do we have to look forward to in the night skies in the coming week?
Paul Well, you know how we do like challenges, you know, and we do like to set challenges. We start off in the very bright evening, twilight. Now this is a challenge. Now, over the last few months we’ve been watching Venus as it gradually, it came out and became really well seen for many hours. And then it’s surprising how quick it dropped back down into the deep twilight during June and into this month, July. So we’re getting towards the last week now in June, July as we’re covering it.
And Venus is really difficult, even though it’s bright. It is deep down in the twilight. But if you look at the right time, you should still spot it just before it actually sets. Now we’re looking. On July 24th because we’ve also got Mercury and Mars nearby as well. And Mars will be harder, Mercury a little bit easier. Venus is the brightest of the lot. So you need to see Venus to be able to guide you to the other planets. So they’re all in the bright twilight. You wanna be looking roughly 20 minutes after sunset. Now, we always say this, you’ve gotta make sure the sun is set and you’ve gotta bear in mind the further north you are then that sunset occurs later. So although we say a time sort of thing, you’ve gotta bear in mind the further north you are the sun will still be up or too close to the horizon. So bear that in mind. But for mid UK around about 9:30 in the evening, Venus will be just hugging the horizon.
You do need a long uncluttered horizon to see this. So buildings, trees, even a hedge might get in the way. Not that I’m saying you should chop down the hedge, you understand. We need all the greenery we can get. But if you do spot Venus, and as long as the Sun is set, you can sweep for it with binoculars. But as I say, you’ve got to make sure the Sun has set.
Now if you spot Venus, try for Mercury to its upper right and it is slightly, well, it is fainter than Venus. Venus is the dazzling one. But we’ve got atmospheric extinction, at this point because we’re looking really low. So we’re looking through a thick part of the atmosphere. You’ve gotta bear that in mind, if you spot Mercury and it seems reasonably bright in binoculars, then waft over to the left hand side and just see if you can spot Mars. It too is really hard now because it’s in the bright twilight. But it is a challenge and after this, sadly Venus is dropping so quickly, it’s gone.
So you are talking probably about the last chance to see Venus on the 24th. 25th an absolute push. But the beauty about that is you can see it closer to sunset, but I would always advise really letting the Sun set before you actually try.
So there we are sort of thing. We start off with a bit of a challenge. Whether you’ll see them is anybody’s guess sort of in the sky, varies so much for everybody. The haze conditions each, it changes, doesn’t it, from day to day, even by the minute sometimes sort of thing. So you know.
Ezzy But it is worth remembering that you can still see things in the twilight sky when it’s still quite bright cuz the sun has just gone down. So it is definitely worth giving it a go to see if you can find those things.
Paul Especially when you consider that you have been able… I’ve been spotting Venus in the daytime sky. I mean, again-
Ezzy Exactly.
Paul -again, the sky conditions have to be perfect. So the Sun’s up, but it has, the conditions have to be right to be fair. However, easier to see. So this, still in the evening sky and it’s a lot easier. Well, but the almost half phase moon, which will lie to the right of Spica in Virgo. Now you want to… you can view around about 10 o’clock for this, because they won’t be set in for a while yet. The next evening the Moon will be up first quarter phase, and this time it’ll be to the left of the star. So the star will be visible because you know the twilight, oh, the light summer nights will be bright. You should still be able to see Spica and yeah, the moon will guide you.
Now moving on. We get to July 26th, so we go a couple of days ahead. We’re still with the Moon, we find around about 10 o’clock. It lies below Alpha Libra, Zubenelgenubi. A big mouthful into it, but it’s a nice wide double star, split easily, uh, using, say 10 x 50 binoculars. I think even you could try 7 x 50 and just see whether… cause that’s down to your eyesight then as to whether you can split them. This is July 26th. And say you don’t have to have it right after sunset. You can leave this till about 10 o’clock in the evening and grab that. And it’s just nice as the Moon is a guide, isn’t it? We often use the Moon as a guide to find interesting ones. And if you’ve not seen a double star, then this is a particularly good one, nice and wide as well.
But back to those bright evening twilight. Two days later, July 28th, Venus is gone. So I’m afraid tough. You haven’t got a guide now, which is a shame because Venus has been really bright . But although it’s lost, Mercury’s still above the horizon. In fact, technically, although Venus will be below the horizon, Mercury lies almost directly above Venus. So if you are able to pick Venus up in the daytime sky before the sunset, and again, very, very careful when you do this, you might spot Mercury directly above it. You wanna be looking roughly towards the west northwest, about 9:30 in the evening. But it is very bright sky, so used binocular to try to spot Mercury because the star Regulus is right next to it. So it’ll almost look like it’s got a fainter companion next to the planet. So if you do get that, see if you can spot Regulus as well. And of course, we’ve got Mars off to the left of it as well. But in bright twilight, we’re gonna be struggling, I think, with Mars.
Ezzy Mm-hmm. That is one of the problems with Mercury because it is so close to the Sun. It’s always going to be in a relatively bright sky, I think, isn’t it?
Paul It is. It’s a pain, isn’t it? I mean, you know, I mean, fancy doing that to us sort of thing. You could… actually, it depends on where you are on Earth. I mean, when I was in the Algarve many years ago, we had a particularly favourable apparition of quite a few of the planets. We actually had me, Mercury, Venus, Mars, Saturn and Jupiter. But the point was, it was a brilliant alignment. It was one of the rare alignments where we had so many planets. In fact, I think it doesn’t happen for a very, very long time. I might not even be around for the next time but I remember being in the Algarve, now from the UK, the ecliptic was very shallow and Mercury, I could just see it, but it’s in very bright twilight. But from the Algarve, we’re about 15 degrees further south. It was surprising the tilt of the ecliptic was steeper and Mercury, it was still bright twilight, but it was a deeper twilight.
See, Mercury’s stood out a treat. You could easily see it. So it does depend on where you are. But here in the UK we have to suffer.
In the summer, Mercury apparitions are poor. They’re always poor. The actual ecliptic is always shallow to the horizon, so it doesn’t get very far. In fact, later on in the month when it’s at … later on in actual fact in August when it’s at greatest elongation, you can’t see it. It’s dropped below the horizon, so you can’t see that. However, still on 28th we’re back with the Moon because the Moon now is just to the left of Antares in Scorpius. So this will be… should be fairly obvious. You should see Antares with the naked eye and you should see the moon just to the left of… it’s quite close. It’s about one and a half, just under two degrees from the actual star. So I always like that sort of thing because it’s a nice orangey star as well. So it shows up quite well in binoculars. It’ll be a good view in binoculars.
Now we are and should mention that. We’ve had noctilucent clouds, but we’ve had a pretty poor showing, so far at the time that we’re recording this. So we’re just hopeful that there will be a few more displays. But at the time of the recording, we’ve had some pretty poor, hardly any noctilucent clouds. And July is when we think the main season will finish. So when you get… the nights are drawing in, you see? So it’s getting darker. You need the light summer nights to be able to see them.
So it’s worth keeping an eye out just in case. I have seen reports and we have seen brief appearances in early August, so there’s still a bit of hope, but uh, you know, it’s one of those, you get years like this, you know, sometimes they’re really good. I’m just hoping that between now and when this comes out we’ll get a brilliant display. You can always hope
Ezzy So much of astronomy is, as you know, sort of set in stone. You can predict it 200 years in advance that it’s nice to somehow sometimes have something that’s a bit more unpredictable. It makes it that much more special when you actually manage to see them.
Paul I think that’s an Aurora. They’re the two really unpredictable ones as far as the… well, something that can be seen by the public. Yes. Now, although I have seen quite a few pictures where people have got sort like quite a cloudy horizon, a few gaps in the cloud and they think the gaps are the actual noctilucent in cloud and in actual fact, it isn’t. It’s just simply a gap in ordinary cloud, which is dark and it’s showing the bright sky behind but that’s one of those things,
Ezzy Which is still very a beautiful thing to see. I know astronomers tend to curse the clouds more than anything else, but. They can be pretty sometimes.
Paul Oh, yes. I don’t disagree with that. It’s just the misidentification that the bright background sky is actually the noctilucent and cloud when in actual fact it’s just the sky. But… They need… if it’s a deep blue, they’re not really the noctilucent clouds. But if a silvery blue shimmering, then it can be quite pretty.
Finally for this week sort of thing, we mustn’t forget the morning sky. I know we have to get up in the mornings but we have got all four giant planets on display and now Saturn is rising around midnight, as it’s only a month away from opposition. So we’ve actually got Saturn in Aquarius. We’ve got Neptune a bit further on the ecliptic. Then Jupiter, which of course is bright. Saturn and Jupiter I saw the other morning, I was quite, you know, I couldn’t sleep.
Just happened to look out the back window, which faces east and there was Saturn with the Moon below it and the Jupiter. Jupiter’s quite plain, but if you’ve got binoculars, search out Neptune and we’ve got Uranus as well. So, well worth having a look in the morning sky for these planets just to get your planetary fix and they are getting well placed till view. That’s the beauty about this at the moment and with the skies getting darker, they are much better for the fainter planets, Neptune and Uranus as well.
So there we are. Quite a few things for this week. A lot in the evening sky, admittedly, but, uh, we like that, don’t we?
Ezzy Yes, there is certainly a lot to be getting on with this week.
So to summarise that again, on the 24th of July, Mercury, Venus and Mars will all be visible just after sunset. Do be sure to catch that because it’s probably one of your last chances to see Venus before it disappears below the horizon, and the half Moon will also be next to the Star Spica. Then on the 26th, the double star Zubenelgenubi will be a good shout to have a look at.
Then on the 28th, Mercury lies next to the Star Regulus with Mars to the left, and also you’ll be able to see the Moon next to Antares in Scorpius. And also throughout the week do be sure to keep an eye out for all four of the giant planets in the morning sky. Saturn is rising around midnight at the moment as it’s only one month away from opposition.
And keep an eye out for NLCs. It’s not been the best year this year, but perhaps you will get lucky and be able to see them. So thank you very much Paul, for taking the time to take us through all of that. If you at home would like to catch next week’s episode, do be sure to subscribe and we will see you then.
Goodbye. If you want to find out even more spectacular sites that will be gracing the night sky this month, be sure to pick up a copy of BBC Sky at Night Magazine, where we have a 16 page pullout 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. For more of our podcasts, visit our website at skyatnightmagazine.com or head to iTunes or Spotify.