See the Moon sit inside the Teapot asterism this week, while a quartet of asteroids moves across the night sky. Find out how to catch these and more stargazing highlights in this week’s podcast guide, Star Diary, 29 April to 5 May 2024.
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Chris: 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: 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 29 April to 5 May. I’m Ezzy Pearson and I’m joined this week by Mary McIntyre, an outreach astronomer and communicator.
Hello, Mary.
Chris: Hello, Ezzy.
Listen to last week’s episode, Star Diary 22 to 28 April 2024
Ezzy: So, what do we have to look forward to in this week’s night sky?
Mary: Well, it’s a very poor week for bright planets this week, but we can still see some asteroids, there’s lots of nice lunar conjunctions. And a really interesting lunar feature to talk about that I want you to all go out and observe.
We’ve still got a couple of comets and a southern hemisphere meteor shower that we might just catch a glimpse of and just a reminder of some daytime atmospheric phenomenon that are commonly seen at this time of year.
So I’ll get the planets done first because again there’s not really a lot to talk about here but the first two days of this week are your absolute last chance to catch a glimpse of Jupiter before it finally drops into solar conjunction.
It’s about mag -2.0 but it’s very very low, kind of lost in the twilight over the west northwest horizon after sunset. For the next two days of this week, the first two days of the week, you’ve got a chance, but then that’s going to be gone. So yeah, Uranus is nearby, but again, we’re not going to see that in the twilight glow.
So it’s a really, really terrible time for planets in the evening sky.
Ezzy: I feel like I should add in there, it is going to get better. I believe the second half of the year is supposed to be much, much better for the planets. So just because it’s bad right now, doesn’t mean it’s going to stay that way forever.
Keep your eyes peeled for the planets. They will be back.
Mary: Yep. It’s all cycles. They will be back.
But we do still have some asteroids to look for, so Pallas is at mag +9.0, that is almost to opposition. When something is opposition, it’s visible all night long, so that is still residing in Hercules, as it was last week.
4 Vesta, mag +8.3. That is moving through Gemini, setting at about 1:45 in the morning. And on 29 April at 11 o’clock, it’s lying halfway between Mebsuta and TOK 19, there’s two stars. Again, like we said last week, it’s really good fun to just monitor the movement of the asteroids through the star field and just see see the differences in the way that they move.
And 3 Juno is also visible below Leo. That is setting at about 4 o’clock in the morning, so that’s kind of visible for most of the night, that is at a mag +10.0. So with all of those asteroids, you are going to need optical aids. They’re not going to be visible to the naked eye. But they’re certainly easy to photograph on a wide field camera if you’ve just got a basic lens and digital SLR, or even a smartphone camera actually. If you can do a couple of seconds exposure it’ll be enough to just pick out that little pinprick of light that is actually an asteroid.
Ezzy: The asteroids, they did take the invention of the telescope to be discovered but it didn’t take much long after that until people were finding these things and that’s three of the four that were first to be found in that list. Last week we’re also talking about Ceres as well which is the first to be found.
Those are some of the brighter ones there definitely.
Mary: Yeah, they’re really nice to observe. I really enjoy observing them and I like to do a kind of constellation sketch and then just draw where the asteroid is moving throughout the coming days. I think that’s a fun activity to do.
Ezzy: Yeah, sketching’s always great. You don’t need to have a fancy camera. It’s good if you’ve got one. but if you don’t, pen and paper’s fine.
Chris: It’s quicker half the time to draw it than it is to try and get the camera to work.
Ezzy: Yeah, you think it should just be, like you, you plonk your camera in place and you snap. And no, no, it’s not. It’s very complicated.
Mary: In the morning sky, we just get a tiny glimpse of Saturn before dawn. It’s rising at about 4:15 in the morning. It lies in Aquarius this week and it’s about mag +1.1. So it is technically naked eye visible, but it is going to be in the twilight, so it will be a bit of a challenge. Also very challenging is Mars.
You may just catch a glimpse of Mars at mag +1.1. That is rising also about 4:30 in the morning in the twilight. Really, really difficult.
On 29 April at 4:40 in the morning, Neptune is 2 arc minutes to the upper left of Mars. That is a very close conjunction, but it’s going to be very, very challenging to observe. But it’s worth mentioning because sometimes I think it’s good to push yourself and see if you can actually spot these.
I think there’s a guide to that in the Sky Diary in the magazine this month.
Ezzy: Is that one that it might be better in other parts of the world? Is it just low in our skies where it’s difficult, or are they actually dim?
Mary: I think that they’re so close to solar conjunction at the moment that I’m not sure it’s going to be particularly good for anybody when the planets are that near to the Sun. That will be a challenging one.
Ceres is also visible in the morning sky, still lying to the left of The Teapot, and you’ll notice the asteroids don’t move particularly quickly across the constellations over time. They are quite distant and small, so you can see their movement each day, but they’re not moving vast amounts of sky over the weeks.
So you’ll still see Ceres near the teapot in the morning, so that is rising at about 2:15 in the morning.
That’s it for planets I’m afraid, there’s not really much else going on in the planet world.
So moving on to the Moon and some lunar conjunctions, this week we’re heading towards the last quarter Moon, so we’re going through the waning gibbous last quarter and into a crescent.
So the last quarter Moon occurs at 12:27 on 1 May.
Before that on 29 April at 3:30 in the morning, the waning gibbous Moon is actually going to be almost exactly in the middle of The Teapot asterism. So anything to do with The Teapot makes me excited. I just love the asterism. Seeing the Moon sat in the middle of it is just really cool.
Ezzy: It does always make me feel, it’s slightly amusing when you have to say something like, oh yes, the moon’s in a teapot today.
Mary: What a great way to get people interested though. People are like, it’s where? And I think it’s one of those kind of asterisms that can be a bit tricky to see in the dawn twilight and it’s good to get people looking for it. I think it’s awesome.
On 4 May at 4:30 in the morning, the waning crescent Moon is going to be just 3º to the lower left of Saturn, and that’s going to make an isosceles triangle with Phi Aquarii, which is up to the upper left of Saturn.
So, I mean, any three things make a triangle, but you know, when you get things like this, sometimes they make a nice isosceles triangle.
I think they look really nice.
Ezzy: Sometimes they are more triangal-ly.
Mary: Yeah, but that will be a nice little photo opportunity.
Now there’s a lunar feature that I want to talk about that is one that wasn’t really on my radar until this year and that is something called Reiner Gamma. When you look at a fully illuminated Moon to the left of Kepler there’s this kind of funny little ring and a squiggle.
It’s called a lunar swirl and it looks like any other highland region. But when you photograph it or observe it when the shadow terminator is nearby, you notice that it doesn’t cast any shadows whatsoever.
And it’s one of several things called lunar swirls on the Moon’s surface where there are these much brighter lit areas that are not highlands because they don’t cast shadows and they’ve been a bit of a mystery for a long time.
They are believed to be to do with magnetic anomalies, but there is actually a mission that NASA are sending to the Moon to study them later this year. And I just wasn’t really aware of this until they asked me if I could help with some outreach for this mission.
And I’ve now photographed it under a fully illuminated Moon, and I did it again under a waning Moon. It really is quite odd to see this bright area that you expect to behave like a crater or a mountain, and it doesn’t. It’s just a completely bright smudge on a flat surface. So it’s an interesting one to look for. And on 4 May, you can look for that. And the crater next to it is crater Riener.
That will have nice topographical definition because of the sun angle. Riener Gamma will not. And it really is kind of mind blowing to observe it. And I can’t believe I’ve had all these years not being aware of it. So, now I’ve become a little bit obsessed with it.
Ezzy: It is one of those things, because I sort of always think of the Moon: it’s grey and black.
It’s one shade of grey and black and you only see things if they’re in shadow. But actually, there is a lot of colours on the moon. Um, there’s a lot of people who, when they do a lot of lunar photography, really try and bring out those different colours. Apparently, for the people walking around there, there was a lot of grey, but occasionally you’d see something that was, had a bit of red to it or something as well.
So I think that must be a fascinating thing, all of these different colours on the Moon.
Mary: Yeah, and there’s a massive chunk of Moon rock at the ESA head office, a friend of mine went there last week. And this huge chunk of rock that is just literally bright white with grey blobs in it. And it’s, you don’t expect Moon rock to look white, but it is legitimately bright white that particular bit.
I’m dying to know whereabouts on the Moon it came from. It’s from the Apollo astronauts. They brought it back. So it’s not all just plain grey. So it is interesting to kind of learn about these new features.
Ezzy: There’s a reason why the Moon’s so bright in the night sky. It’s very… it’s quite… some quite reflective rocks up there.
Mary: Well, on 5 May, the last conjunction is the waning crescent Moon is going to be just 1º to the lower left of Mars in the morning twilight. So again, it’s in the twilight. Mars is not going to be particularly bright, but it should still be a nice pairing through binoculars or if you take a photograph.
I love a lunar conjunction, so I’m always here for that.
Moving on to comets, we still have two comets that are visible this week. 13P/Olbers is moving through Taurus and towards Auriga this week. It’s going to be visible at about 22:15 about 12º above the west northwest horizon. Its current magnitude is going to be around about +9.0, but it may suffer with outbursts, but according to its predicted light curve, that’s where it should be this week.
And it’s going to reach its peak magnitude on the first of July, so we are kind of heading towards a brightening trend rather than a fading trend.
Ezzy: It’s going to be around for a while then, by the sounds of it, a couple of months at least.
Mary: Yeah, and I think it’s really good to observe them when people aren’t talking about them because then you can compare how they brighten throughout each perihelion passage and I think that’s also… again, it’s one of those examples of where something not very exciting ends up being exciting when you compare it to a picture two months later, so that’s why I photograph everything.
Ezzy: There’s like a bit more of a connection between it because you’ve seen it grow up.
Mary: Feel like you’re doing science as well. I, I was there when it was still faint. It’s kind of nice to do both. And the other comment that’s visible is fading and that’s the C/2021 S3 PanSTARRS, that is continuing to move through Cygnus, it is fading, should be a telescope object at around about mag +11.0. Certainly a photographic object through a telescope, but not going to be getting brighter. That one is fading unfortunately, but it is still worth looking for.
One last other meteor shower that I want to talk about is the Eta Aquarids. Now this is active from 19 April to 28 May. It is debris from Comet 1P Halley, or Halley’s Comet, which is probably the most famous comet in history. And the peak is overnight on 5 May. The zenith hourly rate is about 10 to 30 per hour, which is not what you’ll see. That’s a kind of theoretical rate of meteors.
But the thing is, this is actually not very good from the UK because the shower radiant doesn’t actually rise until dawn. But that doesn’t mean that you can’t see meteors belonging to the shower in the northern hemisphere. It just means that you only get about a quarter of them.
I think I mentioned last week, if you observe a meteor shower, the further away from the radiant you look, the longer the meteor trails. So any meteors from the shower that we do get in the northern hemisphere are going to have long trails and potentially be quite bright. It makes them fun to observe, like when a meteor is coming straight at you in short trails, I don’t find them as exciting as when you see one that kind of fills a lot of the sky with a really long trail.
So, It’s not going to be a groundbreaking shower for the northern hemisphere, but I still… our meteor cameras still capture so many meteors from the southern showers, so it’s definitely worth doing. And if you have a radio meteor detector, they work regardless of whether it’s daylight, raining, cloudy, so you can still get kind of rates of meteors happening during showers using that method as well.
Ezzy: And if people are interested in learning how to set up their own radio meteor shower, or several different kinds of ways of monitoring meteor showers remotely from home, we have several guides on how to do that over on our website, skyatnightmagazine.com. I’ll put some links down in the notes as well so you can find out how to do that if you would like to.
Mary: So the final thing I want to talk about is actually more of a daytime phenomenon, and that’s rainbows. We’re in the time of year where we have a lot of April showers, and in the UK, April showers now seem to make it all the way through May as well.
But during the day, if you’ve got sunshine and showers, and the weather is moving from the west, it means that the Sun comes out while it’s raining you on clouds that have moved towards the east of you, therefore you get the chance of seeing a rainbow. Now you don’t see a rainbow every time it rains and the sun comes out, because the angle that the light gets deviated by is always 42º. So if the Sun is there, higher than 42º, you can’t see the rainbow unless you are somewhere high or you have the drone.
But as long as the sun is below 42º in the sky, you can see rainbows on the other side of the sky. And they’re just so beautiful. There’s something so incredibly beautiful about a rainbow. And I think it’s always worth just looking out for them at this time of year because they do seem to be more frequent in the spring than other times of year.
Ezzy: It’s never occurred to me that you can’t see rainbows when the Sun’s too high. Because you’re in the wrong place, it doesn’t work. That’s a new thing I’ve learned today. But thinking back about it, there’s a reason why rainbows tend to be more sort of associated with the spring than with summer, when the Sun is higher in the sky.
Mary: It’s those isolated showers with pockets of clear where you get the Sun shining through. So a rainbow is actually a cone of light rather than just the bow. And it’s always this full circle that extends out 84º in total in diameter. So how much of the rainbow you see will be determined by what height the Sun is.
So if the Sun is very low, that’s when you get that huge semi circular rainbow that we’re all familiar with, with Zippy, George and Bungle. But when the sun’s a bit higher, you just kind of see the top of it, or even just a horizon hugging rainbow.
But it’s important as well, um, to look at night. When the moon is brighter, look at night when we’ve got showers, because you can see a moonbow.
They are caused exactly the same way, they’re on the opposite side of the sky from a bright Moon, but this time it’s moonlight illuminating the raindrops rather than the other way around, and they’re much fainter and get missed quite often. So I’ve still never seen a moonbow myself, I’ve seen lots of lunar halos and stuff, but never a moonbow, so it’s on my hit list for this year.
Ezzy: One of the few times that you actually want to keep track of when the rain is on the weather forecast because you want to do something rather than to try and avoid it.
Well, thank you very much for taking us through all of that, Mary. And if our listeners at home want to keep up to date with all of the latest goings on in the night sky, do subscribe to the Star Diary podcast to make sure you get all of the latest highlights.
But to go over that week again, starting off with the planets:
In the evening sky throughout the week it’ll be your last chance to see Jupiter as it’s very low, and Uranus is now also starting to get lost in twilight.
However, in terms of asteroids, Pallas will be nearly at opposition, Vesta will be in Gemini, and Juno will be in Leo as well, so great opportunity to see those.
In the morning, Saturn will be in Aquarius, though it’s probably not the best time to see it at the moment, and Mars will also be visible as well.
On 29th, Neptune and Mars are going to be very close to each other in the sky, but they will be quite close to the Sun, so it might be tricky to spot those, and do be careful when you are looking at things in the morning sky as well.
And also in terms of asteroids in the morning sky, Ceres is going to be in the region of The Teapot asterism.
Moving on to the Moon, it will be at last quarter on 1 May, but on 29 April, the Moon will also appear in the middle of The Teapot asterism. On 4 May, the Moon and Saturn are going to be close to each other.
That’s also a great time to see Riener Gamma, a feature on the Moon. A surface feature with lots of swirls, that will appear near Crater Riener.
And then on 5 May, the Moon is going to appear near the planet Mars. In terms of comets, we have 13P/Olbers moving through Taurus into Auriga at the moment, as well as S3 PanSTARRS, which is fading away but should still be visible in Cygnus.
The Eta Aquarids meteor shower will also peak on 5 May. It’s not the best to see in the UK, the radiant will be below the horizon, but you should still be able to see lots of long meteors coming through if you want to try and get a look at that one.
And also keep an eye out in the daytime sky for lots of rainbows as the Sun will be at a good height for it with the April showers as well and also if you get lucky you might also see a moonbow in the night sky so keep an eye out for both of those.
So, thank you very much again, Mary, and we hope to see all of our listeners back here next week. 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, which was edited by Lewis Dobbs.
For more of our podcasts, visit our website at skyatnightmagazine.com/podcasts, or head to Spotify, iTunes or your favourite podcast player.