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 skyatnightmagazine.com 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. As we are based here in the UK, all times are in GMT. In this episode, we'll be covering the coming week from 11 to 17 March. I'm Ezzy Pearson, and I'm joined this week by Mary McIntyre.
Hello, Mary!
Mary McIntyre: Hello!
Ezzy: So, Mary, what do we have to look forward to in this week's night sky?
Mary: Well, Mercury's coming back to visit now, which is really exciting. I always love to see Mercury.
So Mercury's climbing higher in the western sky every day, and by the end of this week it's setting 90 minutes after the Sun, so it's a really good time to try to spot it. So it's always fairly low down in the western sky when it's on an evening apparition.
There is going to be a conjunction with a 2.7% waxing crescent Moon on 11 March. If you go out at 18:30, basically Mercury is going to be to the lower right of the Moon. Now this is going to be a challenge because it's all going to be in twilight skies, but with binoculars you might just be able to spot the two side by side.
I always find in the summer months that the really slender crescent Moons can be a real challenge in twilight, but it's really good fun to try to find those. But later in the week, Mercury will get higher and easier to see.
Jupiter is starting to drop lower now, so it's only 27 degrees above the western horizon at 19:30 and setting now at 22:45. So we are starting to lose Jupiter, it is getting lower and lower now.
Ezzy: Yes, it will be back. Eventually, but...
Mary: it will.
Ezzy: Definitely capture it whilst it's still here if you want to take a look at Jupiter.
Mary: Yeah, on 17 March, the Great Red Spot will rotate into view at 20:00. Jupiter's only going to be 22 degrees up at that point, and it's going to be setting fairly soon after.
But you should still be able to see it. I know 22 degrees up is quite low, but the Great Red Spot is big, so you should hopefully be able to catch that on that date.
Ezzy: It's probably not ideal if you're trying to do photography or anything like that, but hopefully you might be able to get something.
Mary: No, the lower something is in the sky, the more atmosphere you're looking through, so therefore the seeing and transparency get worse.
But the beautiful thing about imaging is that you take loads of pictures and let the software choose the ones where the seeing settles and it will then tease out detail that you didn't know was there. So this is why I love imaging as well as visual because it does allow you to access things that you can't always see with the naked eye.
Ezzy: It's always lovely to see things for yourself, but there are things that your eye just can't pick up.
Mary: Yeah, and it's always a challenge when something's very low down.
But using Jupiter again, Uranus is still a companion up to the upper left of it. It's now only 6. 5 degrees away from Jupiter, so the gap is closing between the two of them.
Uranus, you will need binoculars for, and it sets at about 23:30. The set time will vary with your location, but it's around about then, so it is setting about 45 minutes after Jupiter sets. The other planets Mars, Saturn and Neptune are too close to the Sun to see this week, so that's all that we have in planets.
But moving on again to the two comets that we talked about last week, 12P Pons Brooks is about 20 degrees above the west northwest horizon after the Sun has set, and it's moving through into Pisces, so last week it was moving across the square of Pegasus. This week it's moving through Andromeda and into Pisces.
Again, the magnitude... who knows? With this comet, it really just does what it wants. It's predicted to be around about mag +5.0 during March, but it does have these outbursts and it's expected to reach peak magnitude sometime in April, where it might, just might, get to naked eye visibility. But if it does, it's going to be a subtle averted vision object. It's not going to be like Comet NEOWISE was.
Because of where it's moving through at the moment, it's actually going to have a conjunction with the Andromeda Galaxy. So if you go out to find this comet on 11 March, if you go out at 19:45, Pons Brooks is going to be just 8.5º to the lower left of the Andromeda Galaxy.
So as well as being amazing to see that visually, if you scan between them with your binoculars, that will be an amazing photo opportunity.
Ezzy: I always love those ones where you can see something within our own Solar System and then something that's not even in our Galaxy. It's just that sort of really brings home the scale of the Universe that you're looking at.
Mary: Yeah, and especially in photographs when you do often get the colour of the comet versus like some more detail on the Andromeda Galaxy, they do always just look amazing.
I did actually once take a picture of a comet next to the Andromeda Galaxy just with a digital SLR and a 300mm zoom lens, and a two second photograph was all that was needed to get the two of them. So they can be photographed with simple equipment if you wanted to have a go at that.
The other comet that we have is C/2021 S3 PanSTARRS, and that again has got some conjunctions this week. On 12 and 13 March, it's passing through a group of star clusters low down in the southern Milky Way.
The Milky Way is packed with star clusters. If you ever look at the lower part of the Milky Way with binoculars at any time of year, you will struggle to just identify which is which because there are so many clusters. And PanSTARRS is going to be moving through a few of those clusters on those two nights.
So again, another amazing photo opportunity.
Ezzy: I'm really looking forward to seeing some of those photos and if anybody does manage to capture one of the comets passing by something interesting, please do send them in to the magazine. We always love to see them. We'll print the best ones in the magazine.
You can find the details about how to do that in the show notes below but also over at skyatnightmagazine.com.
Mary: So moving on to the Moon, we've got a lot going on this week with the Moon. It's one of my favourite times where we're moving from new Moon through to first quarter. This is one of the best times to just get out there and have a look at the craters on the southern part of the Moon and some of the mountain ranges higher up.
On 13 March, the 16 percent waxing Moon is going to be just 3.8 degrees to the right of Jupiter, and obviously Uranus will be to the upper left of that, so that's a really nice conjunction. And then on 14 March, if you go out at 23:00 the 26% waxing Moon is going to be three degrees below the Pleiades, Messier 45.
So that's always a really nice conjunction to have the Moon near that little star cluster. It's actually my favorite object in the night sky, M45, so any excuse to go and have a look at that, I'm all over it.
On 16 March, we have got the 47 % waxing Moon lying really close, less than a degree from Elnath, the star Elnath.
Now later on in the month, we have loads of what are called clair-obscur effects. Clair-obscur being French for light and shade. And these are these informal names that we give to these phenomenon called pareidolia, where humans see shapes in things that are just random. And there are loads of these on the Moon.
There are so many clair-obscur effects that you can look for. Probably the most well known is the Lunar X and V. I love those two. They are really easy to spot. So if you go out on 17 March, it's a daytime Moon at 14:20 but you should still be able to see with binoculars, or if you take a photograph, look just near the lunar terminator about a third of the way up.
And you'll notice that there is a white X-shape that is illuminated where the sunlight is catching the high rims of the craters there. So you'll see the X there and a little bit further up, about two thirds up, you'll see the V and both of those are very prominent.
Now later that evening, if you go out at 22:15, you'll see another clair-obscur effect called the 'Face in Albertegnus', and that is where the shadows being cast by the crater rim onto the crater floor look like the side profile of a face.
Humans see faces in everything, and this is a great example of that. I think it's programmed into our fight or flight response, it's better to think you've seen a tiger than not seen one. I believe that's how the human brain works.
But that you have to catch it at exactly the right time because when the shadows are too long it doesn't look like a face, when they're too short it doesn't look like a face. So 22:15 is the time for that.
Then if that wasn't enough for you at midnight that night, if you look at the shadows being cast by Ptolemaeus, you'll see Nessie as in the Loch Ness Monster. And that again, is just a high point of the rim of that crater casting a shadow on the crater floor that kind of looks like the head of Nessie. That's one that is a really popular one for people to look out for.
So there's a lot of clair-obscur effects that happen around this phase of the Moon. So definitely go out and try to have a look for those.
There is actually on the Sky At Night website, if you want to learn how you can calculate the height of the lunar features that are casting those shadows, there is a DIY astronomy article that tells you how to do that.
By measuring those shadows and using a little bit of trigonometry, you can calculate how high the features are that are casting them. So that's a really fun activity to do.
Now, when the Moon is set and out of the way, this is the perfect time to start looking for the zodiacal light. And this is an amazing thing you will need a dark sky to see.
There is a lot of dust in between all the planets in our Solar System, and that interplanetary dust basically catches the sunlight, and when the ecliptic, the path that all Solar System bodies take, has got a steep angle upwards, like it does in the spring and in the autumn, you can see this cone of light, really subtle cone of light. With averted vision it usually stands out more.
So wait until it's got fully dark and then look to the west and then just kind of avert your eyes a little bit and you will see a triangle of light. And it does show up on photographs more easily as everything does.
But you will need no Moon, no light pollution, but I've seen it from my village, which is a Bortle 4 sky, so it's kind of halfway on the scale really between the best skies and the worst. So it is doable from the UK, just get away from immediate streetlights to look for that.
And that, that blows my mind that we are seeing the light reflected off these minute particles of dust that are in between all the planets, constantly being replenished by collisions in the asteroid belt.
And seeing something like that again is just one of those magical things for me, I just think it's amazing that we can see that.
Ezzy: Absolutely. It's one of those things I've never managed to be in a place where I could see them or when I am, it slips my mind, but it is something I've always wanted to try and track down at some point is see the zodiacal light.
Mary: Yeah, there's loads of these things. There's also the Gegenschein, which I think I may have faintly caught on a photograph once, but I dunno if that was imagination or wishful thinking or what.
Ezzy: Exactly.
Mary: But you, you need a very, very dark sky for that. And that is where you see this very faint smudge of light at the anti solar point. Exactly the point opposite where the sun is.
That is a real challenge from the UK. But there are loads of these little things that you can see from a very, very dark sky site.
If any of you are going star parties and the Moon is out of the way. Make sure you look for these things as well because they get forgotten about. They don't get talked about very much.
So while the Moon is out of the way, there are also quite a few globular clusters to look out for that are kind of binocular objects. The first one is Messier 3, and that is located halfway between the red giant star Arcturus in Bootes and Cor Caroli. So that is about 45 degrees above the Eastern horizon at 23:00 on 11 March, but it's actually visible all of this week, and it's one of the best globular clusters in the northern hemisphere.
But it often gets forgotten about because everybody always goes to Messier 13, which is the great globular cluster in Hercules. Now, all globular clusters, when you're doing this visually, they need averted vision for them to really pop. And if you've never seen one before, if you just look off to the side, you will see what looks like an out of focus star.
And that is a tightly packed ball of tens of thousands if not hundreds of thousands of stars all in this blob and they are just incredible to look at and they're usually located away from the plane of the Milky Way and at this time of year there are loads of them to look for. So as well as M3, we've got M13, which is the one that gets all of the love, and if you look at the constellation Hercules, it's quite a faint constellation, but the centre of it has got a keystone shape.
If you look at the right hand side of the keystone and follow the line down between the two stars there, a third of the way down from the top is where M13 lies. And with averted vision, again, if you slowly scan down, you will see it just pop into your vision. It's a really, really beautiful one.
Also in Hercules, we've got Messier 92. Now this one's not as bright, but it's still doable with binoculars, and that is east of M13. So if you found M13, just basically find your way across to Eltanin in Draco, and M92 is lying halfway between M13 and that star in Draco. So it will be more of a challenge, that one, but it is still worth looking for.
And there's one final globular cluster, which is Messier 53. That is in Coma Berenices, and I never need an excuse to go and look at Coma Berenices with binoculars anyway, because it has an amazing open cluster there.
But if you find the bottom star of Coma Berenices called Diadem, M53 is less than a degree away from that.
So whatever optical aid you're looking at that star with, you're going to find the globular cluster within your field of view. And as with all of these, if you look at the rather than the globular cluster, it will appear in your peripheral vision.
So there are so many globular clusters out there to look for. These are four that are doable with binoculars, but if you have a telescope, there are others that are more challenging to look for.
Ezzy: Globular clusters are really lovely to look at. There's so many stars, they're so dense, they're just wonderful things to be able to get a view. So I highly recommend our listeners try and get at least one of those.
Mary: Yeah, I mean, these are big enough that you can actually catch them with a wide angle lens, like just a kind of standard lens. You will just see a tiny smudge and you can just pick them up, but with a telescope, obviously, you can start to actually resolve some of the stars. They are a challenge to image well, but you can pick them up with fairly modest equipment.
Ezzy: Well, thank you for taking us through all that week, Mary. It certainly sounds like there is a lot to be getting on with in this week's night sky.
And if our listeners at home want to be sure to keep up to date with all of the goings on in the night sky and not miss any of the highlights in future weeks, please do subscribe to the podcast.
So, to summarise that week again. We start with the planets.
Mercury is going to be returning to the evening twilight. On 11 March, it will be to the lower right of the crescent Moon, so a great chance to see those two together.
Jupiter is dropping down lower in the night sky. We are starting to lose it. But on 17 March, it will be a great opportunity to see the Great Red Spot.
It's also still close by to the planet Uranus, so if you need some help pointing the way to that fainter planet, Jupiter is going to help guide you.
We've also got a couple of comets still making their way through the night sky.
12P Pons Brooks is moving through Andromeda into Pisces at the moment. It's quite hard to say exactly how bright that's going to be because there are lots of outbursts, so keep an eye on that one. But on 11 March it will be close to the Andromeda Galaxy, so potentially a good photo opportunity there.
Meanwhile, Comet C/2021 S3 PanSTARRS will be passing through a group of star clusters in the middle of the Milky Way on 12 to 13 March, so another great photo opportunity there.
Looking at the Moon, on 13 March, it will be to the right of Jupiter and Uranus.
Then on 14th, it will be near M45 as well, the Pleiades, a great opportunity to see those together.
And on 16 March, near to the star Elnath.
Also a couple of clair obscure effects to look forward to on the Moon. On 17 March you'll be able to see the Lunar X and the Lunar V. Then later in the evening the face of Albategnius will also be on view. And finally at midnight you'll be able to see Nessie as well.
Once the Moon has set you might want to keep an eye out for the zodiacal light as well if you're in a dark sky area.
And finally, it's also a great time to take a look at a couple of globular clusters. M3, M13, M92 and M53 are all very visible and on view this month. So if you haven't seen a globular cluster, do look up those ones as well.
From all of us here at Sky Night Magazine, 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 skyatnightmagazine.com iTunes or Spotify.
