Mars meets the Pleiades, Venus approaches the Beehive in this week's stargazing diary.



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 Or to our digital edition by visiting 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. In this episode, we'll be covering the coming week from 15th to 21st August. I'm Ezzy Pearson, the magazine's features editor. And I'm joined on the podcast today by reviews editor Paul Mooney. Hello, Paul.

Paul Money Hello, Ezzy.

Ezzy So, Paul, what are your recommendations for this week?

Paul Well, I hate to say, we're always going on about the morning sky, and I'm afraid we start off again with the morning part of the sky. But that's the way all the cookie crumbles in that August 15th and the hours before dawn, it'll find the Moon to the lower right of Jupiter. Now, if you remember last week, we ended it with Jupiter and Neptune and the moon forming a triangle. That was in the late evening. In the morning, we actually have Jupiter and the Moon getting closer. So the Moon is below Jupiter, but it's moved away from that line-up up with Neptune. That's triangular shape with Neptune itself. The next morning, the 16th, the moon is to the left of Jupiter. And I always mention these simply because I can guarantee that somebody will always come in and say what was that star next to the moon the other night I saw. And then we can cleverly say, 'Well, that was no star. That was a planet. And if you had our sky guide, you know that as well. When the folks get the magazine' It's all in there, tells you what to look out for, as well as our podcasts as well. So it's easy when the Moon is actually next to a bright planet. But that's why I like it when the Moon is next to a fainter planet and guide you to it. Even if the light from the Moon can be a bit of a pain for that. However, by the 18th the Moon does lie to the right of Uranus and it forms a triangle with it and Mu Ceti. So yeah, Mu Ceti is one of those stars some of thing that again... it's not that bright, but he's well worth having a look at. It's a nice star to look at, but it forms a lovely triangle. It's not quite an equal triangle, but you can draw a line from the star right up to the Moon and then across to Uranus sort of thing. So I like patterns. I love patterns. That's why we got constellations. People wanted to make sense of the sky by making constellation, patterns in the sky, and we do it all the time. With astronomy, we're often making patterns with the positions of the planets or the Moon, etc. In the meantime, you may remember last week we had Mars was close to Uranus. Well, it very quickly moved away and now he's moved into Taurus. And the thing about this is that the next evening, the moon is actually to the right of Mars, it's to the left of Uranus, but to the right of Mars. Mars been naked eye, but now Mars is passing below the Pleiades star cluster. So this is this has to be one of those photographic moments, you've got to get out there with your camera. You won't need a telescope for this. This is a wide field view. So you know, head out with a fairly decent telephoto lens sort of thing to get it at 135 millimetres, something like that, just to frame them nicely. Got to bear in mind that the Moon will be bright if you captured this with the Moon in the field of view as well. But Mars is passing now below. Now, it's a funny thing really, because we talk about conjunctions when objects have the same right ascension. But what happens... that's right? If it's a star, But when is a deep sky object, they're an extended object and the Pleiades or over half a degree in size are quite large. So I when I was looking at this, I thought it was quite funny because the Pleiades and Mars are in conjunction, you could argue for two nights.

Ezzy So in a very long conjunction.

Paul Yes. A long drawn out conjunction in this case, Purist would take the centre of the Pleiades as the position. But the planets are a big object. So really for two nights we've got the conjunction taking place on 19th and then 20th sorry, the 18th and the 19th. So it's two mornings long this conjunction as Mars actually passes below it.

Ezzy Given the August weather in Britain at least is probably a good thing, giving you two opportunities to catch it.

Paul Yes nine times out of ten, you can guarantee if there's a special event. You can always guarantee this special event including cloud. We always should put a proviso 'comes with added cloud'. Yeah we don't want to jinx ourselves too much so. But yeah, so you're right, if we've got a couple of nights, you got at least one and you know, a 50/50 chance that you might get the next night clear. So fingers crossed because we just got to hope for the weather. Now on 20th, the Moon then forms a diamond shaped with Messier 45, the Pleiades, Mars and Aldebaran. Now Aldebaran in the Hyades star cluster. You're still in Taurus, of course, but it looks like it's part of the cluster, but it's actually nothing like it is half the distance. So it's just a line of sight effect, just as we see with the actual moon, Mars, Pleiades, and they're all just there are completely different distances, but they just happen to make this pattern for this diamond shaped pattern, so you got the Pleiades at the top, and then you've got Mars and the Moon below that, then below them you've actually got Aldebaran as well. So a bit of a diamond shape is a bit of a skewed diamond, admittedly, but it's a bit of a diamond shape as such there. That's on the 20th. Now we finish off going back to the 18th, but back into the morning sky because you need to be looking sort of thing in a Venus it'll be roughly south of M44. Now M44 is the beehive cluster. This is one of those challenges because it's emerging out of the twilight. So it's very difficult. It's also low. Remember, Venus is low. It's in the twilight sort of thing. So they're both in the twilight. So bright planet. No problem. Yeah, Venus, -4 usually sort of things. So pretty bright. So a lot fainter than that. Technically naked eye, but on a dark, moonless night. But because it's in the twilight, it'll be shown. You see how whether you can you see the cluster to the north of Venus, because that is actually, again, a proper conjunction. Again, you could argue that it's actually, you know, an extended object. But Venus moves so quick, it literally is just one night when it is directly one morning, I should say, when is it directly below the beehive cluster? Messier 44. But again, remember the very low you need a long included a rise in the catch them and catch them before the twilight completely overwhelms Messier 44 the beehive cluster itself thing. So you know. It is one of those balancing acts that sort of thing that you need to catch it quite early. And just as they're rising, keep watching the binoculars and hopefully the hazy, mass stars will shimmer into view. But then you'll watch it fade out as the twilight begins to overwhelm them. But again, it'll be an interesting challenge for photographers. So, you know, we do like interesting challenges. And again, we've got the gallery, so submit your pictures. If you get that, it would be quite interesting to see how well you do.

Ezzy It might just be the lovely way that you described it just then, but to be honest, that sounds quite a nice thing to watch. You know, seeing these distant things fade away into the background as the twilight overcomes them. I think that sounds quite nice. Definitely a challenge, but... there should be lots of things for people to get out there and hopefully see over the course of this week. So thank you very much for taking the time to talk to us about that Paul.

Paul It's a pleasure and keep looking up at the sky because there's always something to look at.

Ezzy If you want to find out even more spectacular sights that will be gracing the night sky throughout the month. Be sure to pick up a copy of BBC Sky at Night Magazine. Well, we have a 16 page pull out Sky Guide with a full overview of everything worth looking out 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 at Night 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 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.