What's in the night sky from 1st to 7th August?



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

Ezzy Greetings listeners and welcome to Start Diary, the 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 1st to 7th of August. I'm Ezzy Pearson, the magazine's features editor. And I'm joined on the podcast today by reviews editor Paul Money. Hello, Paul.

Paul Hello, Ezzy, Looking forward to another exciting week.

Ezzy Oh, that's brilliant to hear that it's going to be exciting. So what is going to make it so exciting for us all?

Paul Well, we have mentioned this parade of planets for a long time, and it is because they're spread out. They're really spread out across the sky. Now there's quite a gap. So we've got Saturn almost on one side of the sky. And if you looking around about 3:00 in the morning, because Yes, it's morning time again, I'm afraid. But that's the way out of the cookie crumbles. So, yes, we've got quite a lot spread out. It's fairly even now between Saturn, then Jupiter, then Mars and then Venus, low down sort of thing as the twilight actually develops. But this week we've got sort of the closing in of Mars with Uranus, and it actually happens today on August 1st, the very first day of this week. So, you know, they just lie one and a half degrees apart. Mars will be below Uranus and, you know, worth looking at in binoculars. But you'll also be able to spot them actually with a wide field, a rich field telescope, which will be a quite a good view. It's not 1.5 degrees, three times the width of the moon itself. So quite fascinating. And I would like to just check the colour. Because Mars is clearly red. I mean, we all know that. That's why it's called Mars the Red Planet.

Ezzy Yes, you can see that with the naked eye.

Paul Yeah, exactly. When you say opposition, it's absolutely blazing there. Almost always think it looks really orange, you know? But there it is. It's shining away. But Uranus is generally green, but it does need a bit of magnification to bring that out. I have spotted it as a sort of hint with binoculars, but a small telescope will bring out the greenish colour of Uranus, so it's nice to contrast the two colours sort of thing. You've got two quite strong colours there next to each other. So Mars is passing below Uranus, and as it does so, as say it's actually closest... this is a conjunc... a true conjunction as well. It does share the same right ascension coordinates, give or take, you know, an arc minute or so, you know. But you know. We're not talking about degrees apart, so we are talking about sort of thing, you know, being on almost the same RA line, which is... That's how we define the conjunctions should be along the same right ascension coordinate. So so that can even be quite a few degrees apart, well apart. But they're still technically a conjunction because they share in the same sort of general coordinates. So there we are so massive passing below Uranus, but he quickly moves past it. So and it's heading towards Taurus, though Mars and Uranus are in Aries at the moment, they're in a bit of a nondescript area sort of thing. But what really helps this is that the Pleiades star cluster is to their left as they are rising now they're over in the east at about 3 a.m.. So, you know, he's quite clear cut, Mars is easily naked eye, so you should better home in on this area itself. So being quite close to the Pleiades it does mean Mars is going to pass below the Pleiades soon as well. So we'll come to that a little bit later. But I'd say it's well worth keep an eye on the motion of Mars because it Mars is closer than Uranus, and that's why it moves past it very quickly. But something that's also moving quickly is Comet Wilson-Harrington. And we mentioned that the other month, because this is a comet, that's an asteroid. There's a comet sort of thing in some astronomical images. It was classed as a comet. Then they found it as an asteroid, a very weird object. So we now know they can be both. Especially if comets of outgassing completely – they're old and they've lost all their volatiles, then, well, basically they're going to look like an asteroid. Or nowadays we tend to call them minor planets as well. So it's also in Aries as well. So what's happening is it is actually moving faster than Mars in the apparent motion on the sky. And it will actually, by the end of the week be above the Pleiades. Mars will still be in Aries and close to the border, so it won't pass into it yet. But Wilson Harrington will be above to Pleiades these. So well with having a look at, see if you can see this unusual comet and so track it as it heads towards the Pleiades. Again, I like it when these objects, these indistinct objects, are close to a recognisable, well-known object like the Pleiades, Messier 45, the Seven Sisters Star Cluster. So, you know, well worth looking at it. If I could just dive... just go go back a little bit sort of thing just to remind it on the first, Interesting enough, the actual line op is Mars, Uranus and then eight degrees from Mars. If you extend that line past Uranus is Comet Wilson Harrington. So, you know, eight degrees is a bit much for typical binoculars, but you should be able to sweep up. If you follow Mars past Uranus and Charon, you should come across a little diffuse blob. There's not many deep sky objects that are bright enough in that region to be confused with. So you should be all right. So that's on the first. But by the seventh, Wilson Harrington will actually be above the Pleiades star cluster. So there we are. So we've got two major planets sort of thing. We've got a comet and we've got a deep sky object as well. I always like it when we get the Pleiades back. The winter skies. Oh. Oh, I'm getting, I'm getting excited. Yeah.

Ezzy The Pleiades is definitely one of those things that it's really beautiful to see. It's relatively easy to see. It's a naked eye object, but it looks even better if you can manage to get it through a pair of binoculars or a telescope.

Paul And we and we love waiting for when we can get it after its absence because of the summer. Once we get it, we know, you know, the skies are going to get darker. Now we're still in the morning sky. And that was about 3 a.m., I suggest, for Mars and Uranus to get the best, they're well up. The sky is relatively dark because it's surprising how quick the sky starts to get dark now. Now the nights are beginning to pull in, but if we carry on, we're into the 2nd August and so 4am, look out for Venus because Venus is on 2nd and 3rd. It's either side, it is motion take either side of Delta Gemini or Wassat is the name. I always want to say "What's that was that was that". It gets worse don't it. But you want to be looking roughly north east. It is low down. Remember again Venus is in the twilight, it is getting lower. So you need an uncluttered horizon, but roughly northeast about 4 a.m.. And this is where you can see Venus either side on the 2nd 3rd August, Delta, Geminorum as well. Now we don't get away from the evening sky completely. Yeah, something more convenient because of course the moon back in the evening sky. so pick out... I like looking for these thin crescent sort of thing and as it gets obviously thicker, it becomes easier to observe the Earthshine becomes easy to observe. And so where we see on the second it's close to Porrima, Porrima is a really tight double star. In fact, Porimma has been opening out and it's a lot easier now in telescopes. A few years ago I couldn't split them with any of the instruments I actually had at the time. Now they're quite well separated, I think it's about four arcseconds and I'm mind being wrong on that sort of thing. But the point is, it's next, the moon, the crescent moon is next to Porrima, it's slightly to the right of Porrima and then to the upper right of Spiker or speaker (Spica) on the third. And of course, the phase is gradually getting thicker as well. So, you know, well worth having a look at. Now, by the end of the week, the moon is grown in phase. It's a gibbous moon. And on the sixth, this is late evening about so well, I'll say about 20 to 11. I know it's getting late. Sometimes these events you have to stay up for, you know. But the moon occults, the star, the Deschuba, Delta Scorpii. Now, the thing about this is that because the star is a naked eye star you should see disappear at the northern edge of the Moon. And it's a very brief. It lasts about 10, 15 minutes at most . So it's well worth observing well beforehand, sort of thing and then carrying on afterwards just to make sure. But with the naked eye you'll see the star disappear. And the thing because there's no atmosphere on the moon, they do go out abruptly. Literally a fraction of a second is gone. And the only difference is when they're double stars and they can fade because one component gets occulted and then the next. So this is Deschuba, Delta Scorpii. Then on the sixth I have set a around about 10:40, that's roughly middle of the UK. But bear in mind that if you further north a) the skies will be lighter, the moon will be lower as well. So it was setting quite soon. So it's a quite short occultation, but you should get the reappearance as well. So, you know, but remember, if you're further north, if you say sort of top end of Scotland, then it will get you the whole of the country can see it. I mean I worked it out, and even Shetlands. But Shetlands is getting close to setting as the occultation and reappearance actually takes place. But there we are. We end the week actually with an occultation of a very bright star, in actual fact. So there we go.

Ezzy It does sound like a really nice way to end off the week. But thank you very much for telling us all about the things that we can see throughout the week. And I hope that some of our listeners will be able to get to see some of them. Thank you very much.

Paul Well, it's a. Let's hope we have clear skies.

Ezzy 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 the detailed star charts to help you track your way across the night sky from all of us here at BBC Sky Magazine. Goodbye.


Chris Bramley 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 Acast, 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.