Comet 103P Hartley continues to pass across the night, while Venus dominates the morning sky in this week’s stargazing guide.
Listen now to catch all the week’s astronomy highlights in Star Diary 16 to 22 October 2023 episode.
Ezzy Pearson: Many of the most beautiful objects in the night sky, like distant spiral galaxies or nebula, are also the faintest and hardest to see. Yet astrophotographers are able to capture their faint light with cameras and reveal the full wonder of the night sky. In BBC Sky at Night Magazine's three part online masterclass series, hosted by our editor Chris Bramley, we'll take a look at three key areas of deep sky imaging.
On 29 September, we'll tell you how you can get started in deep sky imaging. Then, on 26 October, we'll explain how you can deal with some of the impact of light pollution. Then finally, on 30 November, we'll tell you how you can create deep sky mosaics of larger areas. You can either watch along live, or review the on demand recordings after the event.
Visit to skyatnightmagazine.com and click on virtual events to book your tickets now for all three classes and save 20%.
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 Sky at Night Magazine or to our digital edition by visiting iTunes or Google Play.
Ezzy: 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. In this episode, we'll be covering the coming week from 16 to 22 October. I'm features editor, Ezzy Pearson, and I'm joined by reviews editor, Paul Money.
Hello Paul.
Paul Money: Hello Ezzy, and plenty to see this week, I can tell you.
Ezzy: Please do tell us what we've got to look forward to this week.
Paul: Well, let's start off with the parade of planets. Now, I'm not talking about all the planets, but in the evening sky now, we've got all the gas giant planets.
Now, I know the pedants out there will say, hang on, two of them are ice giants. But yes, I grew up with them being gas giants. But yes, two are gas giants, Jupiter and Saturn, and two are now classed as ice giants, which is Uranus and Neptune.
And they're on parade for us. You can see them in the evening sky.
You look about nine o'clock, and we've got Saturn over in the south. We've got Neptune which will obviously need binoculars or a telescope, in the southeast, that's below the circlet of Pisces.
And then rising over in the east, we've got the pair of Jupiter and Uranus, actually, with also the Pleiades nearby, but that's not a planet, is it. Sort of thing. But you know, it's still an interesting object because it's quite close to them. They nearly form a line.
So we've got this parade of giant planets in the evening sky now, and with the sky being dark and these planets being quite high up, this is the time to image them.
So get your telescope rig out, get imaging the planets in detail, and naturally we always like to have the pictures, don't we, sent in to us, sort of thing. We like to feature them in the magazine and on the gallery as well.
Ezzy: Yes, we do always like to see your pictures in the magazine. So if anybody out there has taken any pictures of the gas giants, or anything else that you can see in the autumn skies, please do send them in to us. You can find it on our website, skyatnightmagazine.com. Go to the astrophotography section, or I'll put a link down in the show notes below.
Paul: And of course, they're all visible all week, so this is a great time. In fact, we're really lucky now. We've got them in the evening sky. We've been waiting a long time.
It feels like ages sometimes when they re- emerge into the morning sky, and it feels like, well, nearly half a year, and it probably is nearly half a year before they get into the evening sky.
But it's great to see the, all the planets out, the big planets out on display ready for us as well.
So this is all week. So you've got all week, as long as we have some clear skies, we had some great clear skies recently, and then it's completely gone to pot. So you know, just one of those things.
Ezzy: That is always the things we're always at the mercy of the weather.
Paul: I know. I know, that's the bane of astronomers, isn't it, the weather as such, but never mind, it's one of those things. We do need the rain sometimes. Now, as a night time observer, I'd rather it in the day, and of course the solar observers would rather have it at night.
Can't win, can you? Can't win at all.
Now, the first half of this week, the Moon is hardly present. We'll come to the Moon in a moment. This is because the ecliptic is quite shallow in October, and so the Moon sets quite quickly after sunset. Even though it can be quite a long way from the Sun on the sky, it's actually level with the Sun as it sets.
So this is a good time to get your final glimpses, really, of the summer sky. Because over in the southwest, we've actually got Sagittarius. Now Scorpius is pretty much gone you'll know why in a moment sort of thing, but Scorpius is pretty much gone.
But we've got Sagittarius, and we've got the Milky Way arching up from the southwest, right up through Serpens, sort of like Aquila, enter sort of like Delphinus, and we've got Lyra and Cygnus, and then arches over the sky to go back down for the winter sky, which we'll deal with it another time.
So, if you... this is really your last chance, I think, to really enjoy the low down summer objects. Because it's surprising how long, sort of like the Summer Triangle, Deneb, Vega, and Altair stays with us. I've seen them in December. Admittedly, Altair's virtually on the horizon. But I have seen it sort of thing.
I always think, "there's the Summer Triangle. Hang on, it's nearly winter". Sort of thing. It's one of those quirks of the sky.
So yeah, good chance to really see all the deep sky objects along there, the Cygnus Rift, etc.
Now, I mentioned the Moon, and I said, the ecliptic is quite shallow at this particular time of year.
So you have a final chance, really, to see Antares and... as always, we've often said this, that the Moon acts as a guide. And this is 18 October now, because the Moon, as a crescent, will be just to the left of Antares. Now, I'm looking at around about half an hour after sunset. The sky will be reasonably bright, but Antares is a first magnitude star.
In fact, if you know where to look for it, It is possible to just see it in daylight.
And that's important because earlier in the day around about sort of like just after 2 PM in the afternoon, actually the Moon occults Antares for about an hour, hour and 20 minutes. So it might be worth, you've got a clear horizon towards the south.
It would be worth. Having a look for that. And then as I say, about 30 minutes after sunset, you'll be able to see the crescent Moon to the left of Antares. And again, we always mention Earthshine, have a look for Earthshine as well.
So, it'll be interesting to see whether anybody does manage to see Antares and the occultation by the Moon during the daytime. They are low. So that tends to be a bit of a problem because being low, you're looking through more of the atmosphere, aren't you? So it does tend to dim things a bit more, but even so it'd be worth having a go.
I always like challenges like that. I always like to have a go just in case. It's surprising what you can actually do.
Now I mentioned that we've got the sky all week sort of thing with a summer sky. We've got something else all week. That is a comet. Comet 103P Hartley. It's around about +7.0 magnitude.
And the thing is, it's in an area of the sky that is reasonably well known. You've got Gemini and Cancer. In fact, it's the southern end of Cancer.
And all week, it's moving away from Gemini, from Wasat in actual fact. It's quite a while away from Wasat. But if you take Wasat, and then the bottom end star of Cancer, then you actually have... you've basically got the path of the comet through the course of the week. So being +7.0 magnitude, you know, it's well worth trying with binoculars and a small telescope to see if you spot it.
And of course, photographically, you know, again, you could take photographs of it and send them into the magazine as well. But this is +7.0 magnitude, so it's quite a reasonably bright magnitude for a comet as such.
So, you know, if you missed this Nishimura, if I remember the comet's name right, just the other month because, you know, the weather defeated us as, as probably always. And it was also very low down in the morning twilight and in the evening twilight as well.
If you missed that, well, at least we've got Comet 103P Hartley. And of course the P means periodic, so it does come round on a regular basis. I do forget the actual, year. How long it takes, but it is quite a prominent one and comes back on a regular basis. So yeah, have a go at that comet.
Ezzy: It's also quite a historic comet because it was the location of the Deep Impact mission.
Deep Impact is the name of a film from the early 2000s, but it is also the name of a space mission that, as the name would suggest, struck a comet, impacted a comet, Hartley, back in 2010. So deep impact released a, a impactor that crashed into the surface of the comet, kicked up a cloud of dust and debris that could be watched by the main spacecraft, but also from a lot of observatories round here on home. And we learned a lot about comets from this. It's kind of been forgotten about because it got a little bit usurped a couple of years later when Rosetta turned up at comet 67P/Churyumov-Gerasimenko, and had a much, much closer look at this comet up close.
But I still think the idea that we managed to, you know, go up and make contact with a comet as it was flying around the Sun. Every six and a half years, it comes around. So I always find these kinds of planetary missions absolutely fascinating. That's one of my favourites.
Paul: They are. And you know what? They were absolutely gobsmacked at how much kept coming out after the spacecraft flew past.
They were expecting it to be an impact. It came out and then it'd die down and it was still gushing out as they flew past into the distance. So I always remember those images. They were just gobsmacked, weren't they? So I absolutely remember. Absolutely amazing.
Ezzy: I remember it was, when they were saying how much water was coming off of 67P, the Rosetta Comet, every second, and it was an absurd amount.
And it was like, how is it doing that and still existing for hundreds of thousands of years? That was one of those sort of moments that really solidified in my brain how big these things are. Because sometimes, especially doing the job that I do, you kind of get used to talking about, you know, billions of light years and all of these sorts of things, and then there's something that kind of brings home exactly what size that number is, and it blows your mind a little bit.
Paul: And we can observe the comet. I mean, isn't that great? Isn't that amazing? And it's really bright. +7.0 magnitude is pretty good for us, isn't it? So do get out this week and see if you can actually see Comet Hartley.
Now, by October 20, but you could also say all week anyway... I mean, some of these events, when we're not dealing with the Moon, we're generally dealing with events that probably last all week.
We've got Venus in the, yes, we're back to the morning sky. Early morning sort of thing so we're talking about 5am. The reason why I say about 5am if you leave it too late, you'll have morning twilight start, but Venus is dominating. The morning sky, and it's in Leo, it's in the southern part of Leo, but it's sort of to the lower left of Regulus, the main heart, the brightest star of Leo the lion itself.
The interesting thing here is we're in a period of time before twilight stars where the skies are dark, and now if you've got no light pollution around you, and no source of light, as our own Pete Lawrence has photographed the shadow cast by Venus onto an object.
So you get a sheet of paper, you get an interesting target, probably a soft toy or something like that, because that's what he did once, he was quite funny. And it casts... you can catch the shadow cast by Venus.
We always tend to think the Moon, and of course the sun in daytime, that Venus is bright enough to cast a shadow. But you've got to do it before morning twilight sets in. This is why I suggest about 5 AM.
But Venus is well away from the Sun's glare so it can be seen for several hours now in darkness, which is completely the opposite to, of course, Mercury, even though Venus is an inferior planet as well.
So yes, I'd be looking around about 5AM around about 4:00 to 5:00. It'll be low at 4:00 over in the east, but it is getting higher. And just... have an experiment, you know, do a bit of science and just see if you can see the shadow cast by Venus onto a piece of card.
I would photograph it and I'm sure if you photograph and send it in, just say, look what we've done.
We've emulated what Pete Lawrence has done as well. But it's quite a fascinating little project. Says he, having missed the opportunity every time to do it myself. I always remember too late and either twilight started sort of thing, but I have got a lot of lights around me which can confuse the issue there's a lot of light pollution.
So you've got to... better if you can go out to a dark side and just set something up to see how we go like that. Now still on the 20th, and this is the night 20th into 21st. We have the Orionids meteor shower peaking.
It peaks actually around about, I think, around nine o'clock in the morning on 21st, which really means the night before, 20 into the 21st, is the best time to view the meteors.
Now the zenith hourly rate, which of course is the perfect ideal rate if you're looking under absolutely fantastic conditions, directly above you, is 20. But this is a comet shower, a meteor shower, associated with Halley's Comet, of course. Just like the, I think it's the Eta Aquarids, earlier in there, May, are associated with Halley's Comet as well. So with a zenith hourly rate of 20, you know, it's one of those things that, you know, you might see about five per hour. I know that's dampening the enthusiasm, but you know, if you see them, you're associating, you're seeing a bit of Halley's Comet!
Which... isn't, isn't that neat, eh? To be able to see something... okay, it's for a brief second, it disintegrates in the atmosphere, and then that bit's gone. But even so, I think that's fascinating.
Now, the thing about it is the Moon is in the evening sky, and as I said earlier, it's setting quite quickly. So, as it happens, if you look about 11 o'clock onwards on 20th, the radiant will be over in sort of the east northeast, and it'll be rising higher and higher into the sky.
And so, really, the latter half of the night into the... therefore, the morning of the 21st is going to be the best chance to see the meteors themselves. But really, the Moon is so low in the early evening, once the radiant gets above the arising, you can always start having your own little meteor watch sort of thing, you know.
But I mean, we are talking October now. Now, sometimes it can be warm, relatively speaking, but I would certainly still wrap up and especially we get tend to get a lot more mist and dew. So do wrap up well for that sort of thing. But as I say the radiant rise higher. I think between, sort of, by 2AM to 3AM, it's really well placed to catch some meteors from that.
And of course, if you've got a bit of light pollution, try to hide in the shadow. Try to get the lights behind the building or something like that, or a wall, so you're, you're nicely shaded. So that's opposite the radiant.
But remember, don't look straight at the radiant, because the meteors are foreshortened.
I always generally look 60 to 90 degrees away from that in an arc around the radiant to watch for the longest streaks from the meteors. So that is actually the Orionids.
Of course, it also means Orion's up. Whey! The winter sky!
Ezzy: Absolutely! It's definitely one of the more... there's lots of things to see in Orion, and if people at home would like to get to grips with the Orionids meteor shower, then do go to our website, skyatnightmagazine.com. We have lots of guides about how to get the most out of meteor showers.
Paul: And as we've mentioned, Orion will finish with this week. We're saying, well, as we started with the summer sky is visible. most of the week because the Moon's very low. Of course, once the moon's set, the winter sky is on display by around about five o'clock.
It's high up. Orion is high up in the south. In fact, Sirius is up as well. So you've got the whole of the winter sky.
So you can enjoy the summer sky, at the beginning of the night sort of thing. You can enjoy then the autumn sky through the night. And then you can enjoy the winter sky rising as well.
So, I mean, we've got the best of three worlds there, haven't we?
Ezzy: Absolutely. Lots of things to be getting on with this week and all of the months coming up. Thank you for taking us through that, Paul.
Paul: It's a pleasure.
Ezzy: And at home, if you want to be sure to not miss another highlight that we have coming up in the coming weeks, do subscribe to the podcast.
But to summarise this week, on 16th, we'll have all of the giant planets visible in the night sky.
On 17th, it's your last chance to see the summer sky.
On 18th, during the day, the moon will be occulting the star Antares, which you might be able to see, but you also might not be able to.
And throughout the week, Venus will be dominating the morning sky, but it'll be particularly good on 20th.
Then on 21st, we have the peak of the Orionids meteor shower. And finally, throughout the week, you should be able to catch Comet Hartley as it passes through the Solar System. And the winter sky is beginning to become visible in the morning sky. So, from all of us here, goodbye.
If you want to find out even more spectacular sights 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 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 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 skynightmagazine.com or head to Acast, iTunes or Spotify.
