The Perseids meteor shower reaches its peak activity this week. Find out how to see the sight for yourself by listening to this week’s episode of Star Diary, the podcast from the makers of BBC Sky at Night Magazine.
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Chris Bramley: Hello and welcome to Star Diary, the podcast from the makers of BBC Sky at Night Magazine. You can subscribe to the digital edition of the magazine by visiting iTunes, Google Play, or Apple News, or to the print edition by visiting skyatnightmagazine.com.
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. In this episode, we'll be covering the coming week from 12 to 18 August. I'm Ezzy Pearson, the magazine's features editor, and I'm joined today by Mary McIntyre, astronomer and astronomy writer.
Hello, Mary.
Mary McIntyre: Hi, Ezzy. It's great to see you again.
Ezzy: And you as well. So, what do we have to look forward to in this week's night sky?
Listen to the previous episode, "Saturn rises high in the sky (Star Diary, 5 to 11 August 2024)"
Mary: So, coming up this week, we've got meteors from multiple meteor showers, Mars and Jupiter are going to have a really close encounter, an asteroid reaches opposition, and we've got a few nice lunar pairings to look out for as well, so quite a lot going on.
I'm going to start off with the Perseids meteor shower because we are bang in the middle of the peak right now. So the Perseids is one of the... it's not necessarily the highest rate of meteors in the meteor shower calendar, but it's the one that's more pleasant to observe because it's summer evenings instead of the Geminids when it's -4ºC and you're sitting outside for six hours.
Ezzy: Yeah, I think I know out of August and December, I think I know which one's usually a more comfortable night outside.
Mary: Yeah, I have sat out in five inches of snow before now for the Geminids, but we won't have that during August for the Perseids so, meteor showers are caused when Earth passes through the debris stream of a comet, and the parent body of the Perseids is Comet Swift-Tuttle. It's got an orbital period of 133 years, so it was last in the inner Solar System in 1992.
Because it's quite an old shower, the debris stream is very spread out, so it's active over quite a few weeks, but the peak this year is going to be around 15:00 BST on 12th, so the best nights to observe it are 12 and 13th.
So those two nights together, it's kind of impossible to say which you'll have the higher rate because the peak is going to be daytime, kind of in the middle. So it's always a shower that is very worth observing on days before and after. There have been times when I've had way more meteors on camera the day after the predicted peak.
And even when we get past the biggest peak, there's still going to be quite a few meteors as it tails off over the coming weeks, so it's definitely worth going out to look for that.
The Moon is setting at 23:00 on the night of the peak thereabouts, so that means it's out of the way when the meteor rates are at their highest, which is always before dawn.
After midnight, the dawn side of Earth is facing the debris stream, so that is why we see more meteors. Plus, the radiant of this meteor shower is Perseus, and that gets higher the later that you go through the night. So, it's one that it's worth staying up for because the rates dramatically just ramp up when it gets past midnight.
We see it every year when we go out and observe it, and it really is well worth it. And it starts to kind of dawn break at about 3:00AM. So it's not like an all nighter like you would have in December. It's a really good shower to observe and visual rate is not the same as the zenithal hourly rate that the press will be quoting, but visually you can probably expect to see somewhere between 50 and 60 meteors visually depending on how good your skies are.
So you don't need anything to observe a meteor shower, just your eyes and a comfortable garden recliner. Let your eyes get dark adapted, and just watch and keep a note of what you're seeing as well.
Ezzy: Yes. You mentioned there something called the zenithal hourly rate. That is basically the number of meteors you would expect to see under any absolutely perfect conditions.
If the radiant, where the meteors appear to be coming from, directly overhead. The atmosphere is cooperating, it's very dark. In most cases, you're going to see fairly less than that number that tends to get quoted. So don't be disappointed if it's slightly less than you get that number.
However, that doesn't mean that you're not going to see any. The Perseids is definitely one of the most prolific meteor showers of the year. There's a reason why we bang on about it every time August rolls around.
Mary: Yeah, and it's worth noting as well if you're new to meteor showers that not every meteor that you might see that night will be a Perseid. There are two other meteor showers active at the same time.
We've got the Southern Delta Aquarids, which is not a particularly particularly good shower for us in the northern hemisphere. But if the meteors are coming from that radiant rather than the Perseids, then it will be that one. We've also got the Kappa Cygnids happening, which again is Cygnus that has the radiant, so they're coming from slightly different places in the sky.
And also we have sporadic meteors, two or three an hour every hour, every night of the year. So just because you see a meteor, it doesn't mean that it's definitely a Perseid. Have a look at where it looks like it's coming from and if it's tracking from where the radiant is, then you'll know it is a Perseid.
So good luck with that. And even if you don't see very much, that's a useful bit of science to know how the debris field is behaving. A no show is sometimes just as important a result as a good show. Hopefully it'll be a good one though.
Ezzy: Yeah, it does sort of remind you that there's lots going on in the Solar System.
It's not just a couple of planets and some asteroids. There's a lot of empty space, but there's a lot of stuff in that empty space as well.
Mary: There is, and you never know when you're going to get a bright fireball meteor either. A meteor that's brighter than mag -4.0 is officially a fireball, and they are spectacular to see, and you just don't know when they're going to happen.
They're totally random events, so it's exciting. You don't know what you're going to see.
Okay, so moving on to the planets, the planets are definitely putting on quite a good show this month. We've got quite a few planets to see. I'm going in order of rise and set times with these planets, so we can kind of start off in the evening.
Venus is technically visible, but that is going to be a really big challenge, because it's going to be kind of lost in the evening twilight. It's setting 45 minutes after the Sun. So you will need binoculars to see Venus even though it's a bright planet, but please wait until the Sun has set if you're going to try to find it with binoculars so there's no danger of accidentally pointing your binoculars at the Sun because nobody should ever do that. You might just see it in the West quite low down but it will be a challenge.
Much better is Saturn, though. Saturn is currently at about mag +0.7. It lies in Aquarius, and that is rising at about 9:20PM in the evening, and that's then going to stay visible all night long. And Saturn at the moment is interesting because the way that the rings open and close throughout the cycle means the appearance of it can change quite a lot.
And at the moment, the rings are really closed. It's only tilted by about 3º. So when you look at Saturn, you won't necessarily get the really obvious rings. It will be a really thin ring structure, but it's still incredibly beautiful.
Ezzy: That happens because the planes that the planets move in aren't quite exactly all exactly aligned and so sometimes Earth is a bit higher than Saturn, sometimes it's a bit lower, and at the moment we're just going past it.
So we're actually, right now we are in plane with it, or almost in plane, I think it's the edge on is next year, that's due. So you can't see the rings that great at the moment, but that doesn't mean you shouldn't be taking a look at Saturn because it's another interesting time to look at it. Get to see it without the rings.
Mary: It is. It's really beautiful though as well because it really just gives you the sense of how thin the rings actually are because I think you lose that sometimes when you see them open and how bright they are. You kind of get this idea of them being this dense, thick structure when actually they're really not. So it is interesting to look at it.
Neptune is mag +7.7, so you are definitely going to need binoculars for that. That is currently in the position just below Pisces, and that is rising at about 21:35PM in the eastern sky. And not long after that, at about 23:20PM we will have Uranus rising. That is a little bit brighter at mag +5.8, but for both Neptune and Uranus, you're going to need binoculars to see it.
It will just look like a star, but if you've got a slightly larger telescope, then you will see the colour. It just has a very different colour than the stars around it, but it will be just a pin prick of light because they are very distant planets.
So, always worth looking for those and seeing how they move against the background sky.
And we also have Mars and Jupiter, which are both rising around about the same time, about 12:30PM. Mars is mag +0.9, Jupiter a lot brighter at mag -2.2, and they are going to be visible till dawn.
And they're very close together, and on 14 and 15th, we've got a really special event because Jupiter and Mars are going to be extremely close together. Like so close together that even with a big telescope, they'll be in the same field of view.
So this is the closest conjunction of these two bodies for a decade and they're not going to get this close again until 2023.
So we have a couple of nights when we can look at them and they're going to be on 14th, they're going to be 25 arc minutes apart, and on 15th, 22 arc minutes apart, which is incredibly close.
This is a line of sight effect, the planets are not actually in reality anywhere near each other, they're still 500 million kilometers apart.
The solar system is a flat plane, the planets all move along the ecliptic and they play this game of cat and mouse all the time, so it really is just a line of sight thing, but I really love when you've got two planets in the same field of view as a telescope. I just think it's amazing.
Ezzy: It's also because those are two of the biggest in the night sky and brightest planets that there are out there, and so having the two of them together, that I think is going to be a fairly special sight and people definitely should try and get out and see that.
Mary: Yeah, I'm looking forward to that. It is an early start. You kind of need to be up in the early hours of the morning to see them, but definitely worth doing that.
And Mercury is not visible this week. It's too close to the Sun. It's heading towards solar conjunction. So we can't currently see Mercury.
Jupiter being well placed means that we have a lot of opportunity for seeing the moons' shadow transits and also the moons in transit themselves if you have a slightly bigger telescope.
So I'm just going to point out a couple of those events. There are loads of them. I couldn't possibly talk about all of them.
But on 13 August at half past midnight through to 3:30AM in the morning, we've got the Great Red Spot transiting. So if you want to see the Great Red Spot, that's a good time to do it.
16 August at 4:15AM in the morning, Io's shadow transit begins. And then just over an hour later, Io itself will then begin to transit the disc as well. So you'll get the opportunity to see the moon and the moon shadow on the disc at the same time.
I love shadow transits. They're just so exciting.
On 18 August, just after half past midnight, Jupiter is going to rise. And just over the top of the Great Red Spot, Io will be sitting right there. So having Io on top of the Great Red Spot, again, obviously it isn't actually on top of the Red Spot, but that's what it looks like.
And you'll also have the shadow of Io over near the other edge of Jupiter. So again, the opportunity to see the Moon and the shadow at the same time. And you're also going to then see Europa's shadow just behind the great red spot as well. So there's two shadows and a moon on the disc at the same time, a couple of them very near the Great Red Spot.
So that would be a really nice photo opportunity. And even just visually seeing those moon shadows, I think is just absolutely gorgeous.
Ezzy: The moons of Jupiter do go across the planet quite often, I think Io nips around in something like three and a half days. So they go around quite quickly, but occasionally you get situations like this where there's various factors coming together.
You've got Io, Europa and the great red spot. And I think that's one of the great things about observing planets like Jupiter is waiting for when you can get all of these things in the right place at the right time to see them all together.
Mary: Yeah, and it's going to be kind of staying up most of the night to see it, but I think it's worth it, especially on the summer nights.
But it's not just Jupiter that you can see shadow transits, you can actually see the shadows of Saturn's moons as well. And particularly at the moment, because the disc isn't obscured by the rings because of the tilt, it's a good opportunity to see that.
So on the 14 and 15th August, overnight that night, starting at 11:15PM, we've got Dione shadow transit, and that's going to continue through until about 2:10AM in the morning. That's obviously on 15th, so that's overnight 14 into 15th. And then on 17 August, at 5 o'clock in the morning, if you look at Saturn, you'll see that Titan is almost touching Saturn's south pole.
So it's not going to cross the disc but you'll just see the dot of the moon exactly aligned with the south pole of Saturn, which will be a really pretty sight.
Ezzy: I definitely think that one's going to be a photo opportunity as well. A very unusual site of Saturn with, well, it will have some rings around it, but not its usual rings, and then Titan just hanging underneath it.
Mary: It's always exciting to get one of Saturn's moons. You know, it's kind of like the technology exists now that allows us to do it. And I can't imagine telling 10 year old me that we will be able to do that from our back garden, you know?
Ezzy: Yeah. It is a bit sort of mind bending that this thing that professional telescopes used to struggle to do, and now people can do it in their back garden.
Mary: Asteroid 16 Psyche is at opposition this month, so it reached opposition on 6 August, and that is now visible all month moving through Capricornus. So it's about mag +10.0, so you will need binoculars to see it.
Also, a telescope will allow you to see that. Another thing that will need a telescope, a fairly large telescope, is Pluto.
Pluto is in Capricornus and Ophiuchus this month, and it's not particularly high, but it is observable. It's going to be setting at about 3:45 in the morning. So that's one to look for if you want a bit of a challenge and it is really cool.
Again, photographically, we can get a picture of Pluto. It will be a tiny dot, probably one pixel, but it's Pluto and it's so far away and it's really awesome to be able to do that.
So, this week the Moon is moving through first quarter and heading towards full Moon and on 13 August the Moon is going to sit in the claw of Scorpius. Seems to do that quite a lot at this time of year because Scorpius is on the ecliptic and the Moon is obviously moving along the ecliptic as well.
The night after that at 9:30, just as it gets dark. Look at Sinus Iridum and you will see the Jewelled Handle. That is when the sun is rising over that area and you get the rim of Sinus Iridum illuminated while the rest of the outside of it is dark and it just looks like a jewelled handle of a cutlass or a sword or something. And it's really, really pretty.
On 15 August, the Moon is going to sit above The Teapot spout of Sagittarius, and also that is a good night to look for Cassini's Moon Maiden. Through a telescope that flips the image upside down, it will look like a side profile of a lady with long flowing hair.
Cassini named it after Genevieve, his wife, so that's a good night to look for that.
Finally, on 16 August, the Moon is going to be below the handle of The Teapot, so it'll have moved from the spout to the handle on that night.
Ezzy: One night it's the handle, the other time it's the spout.
Mary: Yeah, I'm immediately thinking about nursery rhymes. "I'm a little teapot." I feel like there's a children's book hiding in there somewhere.
There's one comet that you could try to look for. It's not overly bright, but it's 13P Olbers, and it's certainly looking nice in photographs. It is moving through Coma Berenices this week, and 22:00 it's going to be 20º above the western horizon.
It's about mag +8.4 so you'll need a telescope to see it. But as it moves through Coma Berenices, there's that beautiful open cluster within Coma Berenices that you can see with the naked eye and it is really pretty. So having the comet sitting within that star cluster, I think will be really pretty to see and a beautiful photo opportunity.
With comets they don't always follow the predicted path but should be around about +8.4 magnitude which is achievable with a good pair of binoculars so you should be able to spot that.
Ezzy: You'll need some help but you should be able to see it.
Mary: You will need some help but you should be able to spot it yeah and you'll get more detail in the tail if you are able to take photographs obviously because a long exposure picture will see things your eye cannot.
So one final thing to just mention is that the Sun has been incredibly active again on the fireside, and it is impossible to predict solar activity far ahead of time, but the sunspot group that gave us that incredible storm back in May is still, it's been round again and again and it's currently on the Sun's fireside as we record this.
When that comes back round in a couple of weeks, We have the potential for more X-class flares and potential aurora. So we can't say for sure what's going to happen. The Sun is not predictable in that way and neither is space weather, but keep an eye on all the space weather apps, because I think over the next couple of weeks, the number of flares that we've been getting from various different active regions, I think there's a chance that we may get another nice aurora display from mid latitudes.
So worth keeping an eye on.
Ezzy: August isn't typically the time when you tend to get aurora and you might be fighting against some of the bright nights, but that doesn't mean that the sun can't do its own thing sometimes. So that will be an interesting one to keep an eye on. And also just the Sun at the moment, I know a lot of people have been cursing it because it's been rather warm here in the UK lately, but it's been, because it's approaching its solar maximum at the moment, there's some fantastic things if you are a solar observer as well.
Mary: Yeah, it's not boring at the moment, that's for certain.
Ezzy: Thank you for taking us through that all, Mary. If our listeners at home would like to get even more space highlights, please do subscribe to the podcast and we'll be back here next week.
But to summarise this week again, it's the peak of the Perseids meteor shower on 11th and 12th, so keep an eye out for those.
You'll probably want to be observing sometime after 11pm when the Moon is out of the way.
In other Solar System news, Venus is going to be in the evening twilight. That one will be a bit challenging to see. However, the other planets, Saturn, Neptune, Uranus, Mars and Jupiter will all be rising throughout the evening from about 9:20PM right the way through to 12:30PM. So some great opportunities to see those.
Particularly on 14 and 15th, keep an eye out for Mars and Jupiter as the pair will be having their closest conjunction, their closest meeting for over a decade. So definitely try and see those two together.
Taking a closer look at Jupiter, on 13th we'll see the Great Red Spot make a transit across the face of the planet.
On the 16 and 18th there'll also be two moon transits, two moon shadow transits going on, as well as some over on Saturn on the 14-15th and 17th as well. If you fancy even more of a planetary challenge then try and keep an eye out for Pluto this week which will be reaching its highest point at about 11:45.
There's also asteroid Psyche which reaches opposition on 6 August and Comet 13P Olbers will be moving throughout Coma Berenice this week.
Looking at the Moon, it will be moving from first quarter towards full throughout the week. On 14th is a great opportunity to look for the Jeweled Handle and on 15th Cassini's Moon Maiden as well.
And finally, keep an eye out on the Sun. There is some fantastic solar activity that's expected. to come back around in the next couple of weeks. There may even be some aurora if we get very lucky. So do keep an eye on those, and we hope to see you all back here next week.
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 Night Magazine, which was edited by Lewis Dobbs.
For more of our podcasts, visit our website at skynightmagazine.com/podcasts, or head to Spotify, iTunes, or your favourite podcast player.
Listen to the next episode, "The Blue Super Moon rises (Star Diary 19 to 25 August 2024)"
