The Supermassive Podcast - 41: BIG Observatories

Episode Date: May 27, 2023

We love stargazing on The Supermassive Podcast, so we thought it was about time we had an episode on the future of ground-based telescopes. From the brilliant named Extremely Large Telescope to the Square Kilometre Array Observatory, Dr Aprajita Verma from Oxford University and science journalist, Sarah Wild, tell Izzie and Dr Becky about the observatories that will transform our understanding of the universe. Searching African Skies by Sarah Wild - https://www.waterstones.com/book/searching-african-skies/sarah-wild/9781431404728 Send your questions or astrophotography to [e-mail], tweet @RoyalAstroSoc, or find us on Instagram @SupermassivePod.  The Supermassive Podcast is a Boffin Media production for The Royal Astronomical Society. The producers are Izzie Clarke and Richard Hollingham. 

Ego is a million pound telescope. They've got these antennae that look like giant Christmas trees. How is anyone going to cope with that amount of information? Hello and welcome to the Supermassive podcast from the Royal Astronomical Society with me, science journalist Izzy Clark and astrophysicist Dr. Becky Smethurst. Now, you know, we love a bit of stargazing on the Supermassive podcast, so we thought it was about time we did an episode on the future of ground-based observatories. So from the brilliantly named Extremely Large Telescope to the Square Kilometre Array Observatory. Gosh, I really love these names,

but I personally think the supermassive telescope also has a very natural effect. It totally is. It totally is. And the king of stargazing, Dr. Robert Massey, deputy director of the Royal Astronomical Society. The king of stargazing. Have we correlated him?

Yes, it's a new one. Yeah, he's been officially correlated as the king of stargazing. The royal society. So, Robert, what I really want to know is, have you ever used one of these international observatories? Yeah, I have. I mean, back when I was doing my doctorate in the 1990s,

I mean, I've visited some afterwards since then as well. And they are an unforgettable experience. I mean, you obviously remember us going to Herstman's, which was like the sort of the UK version of these things but from the 1960s when jet travel became more affordable astronomers realized you know the uk for example was not the best place to build a telescope so that's why they were cited in much better sites all over the world and why you ended up with the one la palma which is where i've been and tenerife which i've also been there but also places like hawaii and chile and Chile and Australia and South Africa,

basically places with clearer skies and more reliable weather than the UK and high up above the atmosphere as well. But of course, we should remember that, you know, in the UK, we've got really good radio facilities like E. Merlin, and that's a lot less affected by the weather. Yeah, you can actually observe through the clouds. Exactly. Like some further level telescope at John Rumbank. But Becky, you've used quite a few of these observatories dotted around the world. So what are the different ways that astronomers can use them?

Yeah, I mean, traditionally, as Robert said, you would actually go yourself and you would fly out. So, for example, you would do three nights in La Palma using the Isaac Newton telescope or you do a few nights in Hawaii, for example. So I've done that and I've done that with the Caltex millimeter Observatory, which is called the Golf Ball on Mount Akeia in Hawaii. It's no longer an operating telescope anymore, but it feels like sort of a rite of passage for astronomy PhD students that you must go observing at some point. And if that doesn't include some form of bad weather, then you haven't actually been observing. But essentially when you do go observing, what you're doing is essentially you're sat in the control room of a telescope,

you know, up this mountain, very isolated. And all you're really doing is typing commands into a computer these days, really. You're not like turning, you know, really cool like switches and knobs that you would have been doing in really old, you know, control rooms to sort of control your telescope and move it around. So, I mean mean nowadays you can do that from anywhere which is not as exciting as

flying to hawaii you know connecting to a telescope observatory system you know to observe so i've done that with the caltex millimeter observatory in hawaii which actually worked out great because you know they're like 11 hours behind us so you're observing in their night time which is your normal day time so it's just like a normal day at work so but now many observatories are going the way of what i call sort of the the space observatory operations in a way so if you apply for time on say the hubble space telescope or jdgrist for example what you do is obviously you'd you'd propose for the time and if you were successful they'd then say right tell us the coordinates of the objects you want to observe tell us what instrument you want to use how long you want to observe it for give us all the instructions and we'll sort it for you we'll make it happen yeah we're being like the you know trained telescope operators that can

actually use these billion dollar facilities rather do not. Because that is one of the scariest things in the right of passage of a PhD student is like, here you go, here's a million pound telescope. Have fun. You just think, don't break it, don't break it, don't break it. And so a lot of ground-based observatories are going that way now as well,

especially when they're, you know, much more sort of sophisticated. We're seeing coming online, for example. And I've done that too. So I've done the in-person, I've've done uh remote observing you know myself from a computer and then i've done the submit essentially to a queue with all the instructions that you want it's actually quite fun i'm actually doing this right now with the hobby eberly telescope in texas um it's taking data for me probably as we speak because it's early morning here in the uk so and i keep waking

up every morning to like hey you've got new data and it's like it's it's early morning here in the uk so and i keep waking up every morning to like hey you've got new data and it's like it's it's like you've got mail but you've got data it's really nice and you just get to go on the system and download it that day and you know slowly your sample builds up and builds up so you know each each different way has its own fun things about it but i think my heart will always be in favor of going up a mountain yeah and actually doing the observing yourself because once you set an exposure going say you're observing a distant galaxy like i do it's like yeah half an hour you know three 10 minute chunks i'm just gonna nip outside lovely just gonna look up at the stars lovely so the world's most advanced

visible light astronomical observatory is the European Southern Observatory's Very Large Telescope, aka the VLT. Love it. It can see objects that are four billion times fainter than what we can see with the unaided eye. But we want more. More! We demand it.

And so with that, the extremely large telescope is now being built in the Chilean Atacama Desert. But why is an extremely large telescope better than a very large one? And it's something that I genuinely asked Dr. Aprojita Verma from the University of Oxford and project scientist for the UK ELT programme. UK ELT program? It's always nice to have bigger telescopes. And the main reason is the bigger, what we call the mirror, so the thing that's collecting all the photons from the universe, the more photons we can collect. So essentially, we're looking at light buckets, so things that just collect lots and lots of very distant photons and very faint photons. And just to give you a feeling of what that means in terms of what we call sensitivity, so how much light it can collect. If you were to light a candle, for example, on the surface of the moon, the ELT is sensitive enough to detect that single candle

flame at that distance. Obviously, we can't light candles on the moon because we don't have any oxygen, but it really is an incredible collecting device. The other reason to go from a very large telescope to an extremely large telescope is that we basically can also improve the spatial resolutions of the detail that we can see in the universe. And that can be of any object. So for example, for the Hubble Space Telescope images you may have seen, we're looking at things that are about 15 times sharper than what you see there. And compared to the James Webb Telescope, it's about six times better than that. So it really is a precision instrument, both in terms of sensitivity and detail. Yeah. And I mean, first of all, I love the idea of just calling telescopes light buckets. I think that's going to be my go-to phrase going forward. And so with that, just how big is the extremely large telescope? We define the size of a telescope by the main reflecting surface, which we call the primary

mirror. And in the case of the ELT, that is 39 meters across. And I know that's an odd number to visualize. So it's quite difficult to think what 39 meters is. But if you imagine a football pitch and in half of the pitch, you drew a circle, then that's roughly about 39 meters. So next time you go and watch your favorite football match or you see it on TV, just think of a lovely mirrored surface right in half of that pitch.

So it really is massive. And the enclosure that these telescopes sit in are kind of like football or sports stadia. They're really massive because that whole structure that goes around it, they all need to be protected from the elements. So it really is stadium-sized astronomy. Yeah. Oh my goodness. So what is the Extremely Large Telescope looking to find? What are some of those core aims? With these kinds of observatories, they really are what we call general purpose in the sense that they're going to really tackle a huge range of open science questions. We

can think about two types of science. We've got the kind of science that we're doing now, and we can see how that might benefit from more sensitivity or more spatial resolution or both. And so we can look at kind of science cases like the first stars and galaxies that formed in the universe, the ERT is powerful enough that it can collect the signatures of light from those very, very distant objects. They're forming a few hundred thousand years after the Big Bang. And we'll be able to actually not just see them, which is what we are finding with Hubble and with James Webb, but we'll also be able to take spectra of them. And taking spectra gives us a lot more information about the chemical makeup, the evolutionary state, how stars in them are moving and the gas.

So there's a lot we can learn from spectroscopy. But one of the main drivers to build an extremely large telescope are looking at planets that orbit stars outside our own solar system. This is quite a hot topic. And over the last 20 years, we've gone from zero to a few thousand of these, or I think it's more like 6,000 right now. But it's really actually challenging to find them. But we can also, with something like the ELT, actually look for these signs of life in what we call direct detection of the exoplanet light. So this is the reflected light from their parent star. And we'll be able to characterize the atmospheres of these planets and maybe even detect rocky planets, which are really, really impossible to get's looking for exoplanets. What is the benefit of using, say, ground-based telescopes over space-based telescopes?

So there's lots of reasons to do it. The main thing is that when we look from the ground, we have this lovely layer around us that protects us from the harshness of space called the atmosphere. Thank goodness. that protects us from the harshness of space called the atmosphere. Thank goodness. Yes, thank goodness. That also has a lot of turbulence in it. And what that does to things we observe from the ground is it essentially blurs out every image to about the same size.

So that might make you think, well, why do we bother building things from the ground when we can put these incredible facilities out in space? There's several things. So one is that when we build things on the ground, obviously, it's a lot more accessible. We can take advantage of new technologies. We can do regular maintenance. We can have long lifetimes. When we put telescopes out into space, they're very expensive. They go out with tried and tested solid technologies, which means essentially they may be 10 to 20 years behind where we are now on Earth. But it's not to discredit those technologies. They definitely were, and they have to do incredible things

to go out there into space and observe. So the challenge really is how do you get space quality images from the ground? We have this technique called adaptive optics, which essentially can remove the effects of the atmosphere. And so we know what in a perfect system, what something like a very distant star would look like to our camera through a telescope. But then we actually observe a star and we see it's very different. It's actually kind of jumping around. But to recover what the star really looked like or any astronomical object,

what we can do is monitor stars, have this kind of theoretical best performance that we know from the optics. And the difference then is really what the atmosphere is doing to the image. So there's this really, I mean, I just find it really astounding that we can even do this, but essentially you look at that difference, you imprint it onto one of the mirrors in the chain or the inverse of it. And what that essentially does is cancel out the effect of the atmospheric turbulence. And that, I mean, in itself is a huge technological and engineering challenge. But the fact that they can do this in the ELT system with a really large mirror with about 6,000 little pistons behind it, constantly deforming the surface of the mirror is really quite impressive.

And that's what all modern observatories that have adaptive optics built into them have this, what we call a deformable mirror. And that's what lets us get space quality images from the ground. Oh, wow. Gosh, lots of different systems going on there. So where are we at with ELT and its development? When can we hope to see, you know, those first light and those first images? So I'm really excited to be able to say that, you know, it's well under construction. So, you know, they've levelled the top of a mountain in Chile. As you do.

As you do. They've made some incredible looking foundations. You can look at some images on the European Southern Observatory website, and they kind of show the evolution of the growth above the ground. So we had a spaceship-like foundation footprint, and then now we're really above ground. You can see the building taking shape and even like the kind of metal structures that will hold the dome are now being put up. And there's a webcam that you can look at and see the progress in real time. So it's really, for me, it's quite exciting.

But we can expect those first photons towards the end of this decade. So hopefully in the next five to six years, we'll be getting those first light photons through the ELT. Oh, how exciting. And speaking of excitement, what are some of the things that you are most excited about when it comes to ELT? Oh, there's just too many to mention. I think the most exciting thing about the ELT isn't the stuff that we can predict. So I personally work on galaxies and I'm really looking forward to looking at those first galaxies. But with these kind of huge changes in technology and scale with telescopes, what we know is that it

also then produces transformative science. And these are the things that we actually can't predict. So it's not what we're doing now and how can we do it better within the ERT. It's really stuff that we just don't even know is out there. There's just so much potential here across all fields of astronomy and cosmology even. So we're really looking forward to these first photons coming in. Thank you to Aproduta Verma. Now, luckily for us, we can also explore our universe across the whole electromagnetic spectrum, not just the optical.

I'm probably biased because that's the biggest surprise. What a surprise. I look in. Now, those up north will be familiar with the Lovell Telescope at the Jodrell Bank Observatory. Big, beautiful thing, isn't it, Izzy? Just absolutely gorgeous. And I actually watched the

2015 eclipse from there which was definitely an experience of the partial eclipse that we had of course you did i can't i can't explain to you how cool it was to be like oh look a partial eclipse and then turn around 180 degrees and be like oh look beautiful telescope i love it when you're on the train up to manchester and you go past it i always look out for it it's amazing it is amazing isn't it um anyway never mind one fairly large telescope we have here in the UK but taking astronomy to the next level is the square kilometer array observatory and to tell us more we're joined by science journalist Sarah Wild co-author of our book the The Year in Space. Now, Sarah, one of the chapters you wrote

was about the square kilometre array. So paint a picture for us. Describe what does this observatory actually look like? Well, to start off with it, it's going to be giant. It's going to be properly massive. Because once upon a time when astronomers sat around and thought, what do we want to build? The biggest possible telescope we could. They came up with the idea of a telescope that had a receiving area of one square kilometer. And back in the day, they envisioned it as one telescope. But in 2012, they decided to split it into two. And there's one telescope in South Africa and another one in Australia. And together, the entire thing is called the SKA Observatory. And each different section will look at different parts of the electromagnetic

spectrum. Yeah. So how are those two sites linking up? How does that work? So it's a thing called interferometry, which means that all the different dishes on the different sites are all acting as one giant instrument. So in South Africa, for phase one of the SKA, which is under construction at the moment, there are going to be 197 giant dishes. These dishes are like the size of a three-story building, like properly massive. So in Australia, they've got these antennae that look like giant Christmas trees. They're about two meters high. Initially, they were kind of sore when all of us journalists were calling them Christmas trees, but I think they've kind of lent into it. It's the best description.

They do look like Christmas trees. Like I want to decorate these things. I can just see them now with baubles, but that might make them a little bit less useful. So the different dishes and antennas look at different parts of the electromagnetic spectrum. So the SKA in Australia is called SKA low. And the radio frequencies that picks up on the wavelengths are about one to six meters. So pretty long. one to six meters, so pretty long. Whereas in South Africa, on the other hand, the dishes are picking up wavelengths of about three to 30 centimeters. So the longest one is about the

length of a ruler. So it's predicted to come online and start giving us data late in the decade, maybe 2027, tentatively, I want to say. So when it does come online, Sarah, like how will the SKA transform our understanding of the universe? Well, they allow us to do things that we weren't able to do before. Well, not as well. So because you've got this giant distance between the two telescopes, as well as the fact that there's so many antennas and dishes, you get a very, very high resolution. So you get a super sharp picture and you can see things in a detail that we haven't been able to so far. And that means that we can answer some really cool questions. Well, we hope. So in Australia, for example, they're going to be looking at the cosmic dawn. So after the Big Bang, we're not entirely sure what happened.

And when the first stars came on and the first galaxies formed, and with the kind of sensitivity we're going to get from SKA low, we'll be able to probe and understand what was happening in those first few million years. You've also got really difficult questions like, why is the universe accelerating? What's causing it? What is happening with dark energy? What can we learn about it? And because of this precision, we're going to learn things we weren't able to before. And then, of course, there's always the question, are we alone? And are there aliens? I think that astronomers always get sick of us asking this question of how can we find out if we are actually alone? The SKA will be so sensitive that we should be able to find out

if there's anyone nearby. There's anything out there. Yeah. I like that. What a selling point. Yeah, we'll do this cool science, but if there's anything out there. I mean, those are some pretty big aims, you know, just a few simple questions that we want to set out and answer.

So how is this different from other radio observatories? Why is this really pushing the boundary? Well, as I said, it's size and it's also the kind of technological sophistication we're seeing. So once upon a time, about 10 years ago, I was at the SKA engineering meeting in Canada, in Banff, and they were talking about how are we going to power such a giant telescope? Because if you think about it, the sites really are in the back of beyond. To get to the site in Australia, you need to fly in or it's something like a six, seven hour drive. Similarly, in South Africa, it's pretty far from anything. So how are you going to get power there? And at that time, they were all like, well, you know,

we're not quite sure it's going to be really, really expensive, but we'll just hope for the best. Today, we have the kind of renewable energy technology where that's sort of a solved problem, because we can have renewable energy in these remote sites. The same thing happened with our data crunching and technological capacities. Whereas 10 years ago, the kind of data crunching that we have now just didn't exist. What we're seeing with this next generation telescope is a kind of technological sophistication that we just didn't have before. Amazing. I think I've heard something as well about the speed that it will take data is almost faster than we can actually get the data

from where it's stored as well. It's just insane. It is absolutely mind-blowing how fast they're going to be able to crunch data. And the exciting thing about projects like this is that those technological advances will trickle down to us. In the same way you've seen with CERN and other giant science projects,

intergovernmental science projects, is that this will eventually benefit us. It's not just pie in the sky, you know, let's map the magnetism of the universe for LARCs. We will eventually see the benefits of this. Yeah, I mean mean radio interferometry already gave us wi-fi so you know what else will it give us thank you very much we're literally doing this call it interview right now because of an invention of radio interferometry like combining signals from all those different dishes is like getting the signal back from your router right so yeah

the benefits of radio astronomy are endless. And I guess one thing that I just want to know, is there anything in particular, Sarah, that you're really excited about? Well, as you may have noticed, I am kind of super excited about it. I think it's remarkably cool. Just a little bit.

Well, I mean, so when I was at university, I was studying radio astronomy with some of the people who went on to be part of this project and the cosmic dawn and these targets of things that we know we don't know but there's so much that's going to surprise us that we didn't imagine was out there in the universe and Sarah I feel like we have to mention that you not only as a co-author of our book the year in space but you've also written an entire book on this as well so what's that called and where can people get it? So I wrote a book called Searching African Skies, the SKA and South Africa's quest to hear the songs of the stars.

And you can get it on Amazon. You can get it in hard copy and you can get it on Kindle. And it was basically a story because we've already discussed my endless enthusiasm for astronomy. You fit in very well here. But I would come. Am I here? Am I in? Yeah. astronomy. You fit in very well here. But I would come... Am I here? Am I in? Yeah, you're in a safe space. So I would come home from work and I would rant to my then boyfriend,

now husband, about the fact that I only had 300 words to tell people about this. And then he was like, well, why don't you write a book? And I was like, I can't do that. And then I kept on complaining and he was like, oh, for goodness sake, Sarah, please write a book and I was like I can't do that and then I kept on complaining and he was like oh for goodness sake Sarah please write a book um and so I wrote the book also because so that I could explain it to people like my mom um who's not a scientist and I wanted to tell her about this cool thing and so I wrote a book amazing so to African skies beautiful yeah everyone should go buy a copy right now absolutely and we'll link it in the episode description as well so there's no excuse yeah sarah thank you

so much it's been really great well thank you this is the super massive podcast from the royal astronomical society with me astrophysicist dr Becky Smethurst and with science journalist Izzy Clark. There is just too much to talk about in this episode so I'm pulling out the producer card and I want to talk about one more observatory and this is one that a lot of people have referenced in previous episodes but we've not really focused on it and that's the Viracy Rubin Observatory. So Becky if if people haven't heard of it, what is it? Yeah, I mean, I'm not surprised so many people we've interviewed have mentioned it because it really is like the next big thing that's sort of on all of our radar. So it used to be named the Large Synoptic Survey Telescope. So LSST might have been, you know, sometimes people might have

heard of it as that name. And then it got a rename to the Vera Rubin Observatory, I think it was back in 2019. And that's, you know, very common as telescopes sort of near their completion during construction and stuff for them to get renamed. And it's being built in Chile right now. And first light is expected around about summer 2024. So this is why, you know, we're getting there now,

we're a year or so away. So it's getting to the point where we're like, oh, we can actually get excited about this now. And it's an 8.4 meter main mirror that this telescope has got. So that's very similar to the VLT in Chile as well. So that's four eight meter telescopes. The thing is, it's got three mirrors in there to help

collect the light so one sort of collects light and then the other two actually focus it down to the detectors and those three mirrors are arranged in such a way to give it a much bigger field of view than the vlt even though it's the same size telescope so i mean the field of view is is huge for an astronomer when you say it people are like wait what it's 3.5 degrees across the field of view to put that into context that's seven full moons across in terms of what this telescope will see in one single pointing so if you compare that to the vlt the very large telescope that i said it's that similar size to, that field of view is just 0.45 degrees across. Oh, wow. So less than a full moon.

And that's using like the one instrument that can do that. Most other instruments are like tiny fractions of that. So it's a big, big deal. And the reason that it's got such a huge field of view is that it is a survey telescope. It's not going to be like the vlt where you know individual astronomers or teams will apply to be like i want to do this thing with it it is going to use that large field of view to survey the sky night on night in fact it should

be able to cover the entire sky in around about three nights total because it's got such a big field of view you know this idea of like splitting the sky up into these little postage stamps and then just slowly adding more and more and more to it and it's also going to do that going to record those images with the largest digital camera ever made okay of course it is 3.2 gigapixels i feel like um what is it in back to the future when he's there like 1.2 gigawatts it's just gonna be i'm just gonna clip you that and just put it on loop i mean it's incredible though it means about like 20 terabytes of data a night so it's also a huge data challenge as well like how you're gonna record that so i mean his plan is to literally survey the sky for 10 years in this way yeah just collecting more and

more light getting the fainter and fainter things you know like distant galaxies resolve their shapes so 20 billion galaxies is the estimate for how many it's going to get, which is insane. Blimey. But what are its aims? Obviously, it's as technology advances, our understanding and how we understand our place in the universe changes with it. So what is the Rubin Observatory setting out to tackle? You know, what are the big checkboxes? Yeah. So first one is like essentially an inventory of the solar system because if you're going to survey the sky like once every three nights you're going to see all the things that change in the sky every three nights essentially

so that's going to include things in our own solar system like obviously asteroids planets all that kind of stuff so they reckon there's going to be around about six million solar system objects that are going to be catalogued some of which we don't know right now about so it's you know it's a big deal getting six million solar system objects but also in terms of that changing in the sky you're also talking about things like supernova so you can study supernova more but you can also trace the expansion of the universe with supernova if you're detecting them you know on a regular, you're getting more and more of them to catalog. But also then things just like changing in brightness. So stars changing in brightness or say a black hole that's taking in material and the material is glowing far out from the black hole.

You can see that changing in brightness. So you can probe that kind of physics too. So what we call the transient community in astronomy they're not yeah they're not transient through astronomy they're they're looking at the things that change you know in the sky night or night they're very excited for the rear rubin observatory there's estimated to be around about 10 million alerts a night in terms of things changing in the sky yeah it's it's one of those things where we've had to do a lot of pre-work in terms of how are we going to deal with this?

Well, that's what I was just going to say. How is anyone going to cope with that amount of information? Yeah, I don't think anyone... I'm processing that. Yeah, nobody wants like 10 million push notifications on their phone per night, right? We've gone beyond that. So I think we're going to start having this system where you have a machine look sort of at the alerts that come through. And it's you know known solar system bodies all those kind of things will get probably tossed out known variable stars get

tossed out and then you'll get a human to look at the rest of the things that are left hopefully a much smaller fraction of the things that we actually think might be interesting again so that people can know if you know a supernova's gone off or something like that so you know anything that's going bump in the night, I mean, you're on it. But then also, I mean, it's great for people who are interested in galaxies. So people like me, you know, their shapes and their star formation rates and how they change and evolve with time. This is going to give you a huge sample, 20 billion galaxies by the end. We're going to be absolutely spoiled.

Our current biggest is a million in the northern sky. And this is estimated to be 20 billion just for the depth it's getting to in the southern sky it gets to a point where you can't even imagine it like it's yeah just ridiculous numbers that you're like i can't even compute mentally i mean let alone actual computing power to process this but you know this is neck really is next level yeah and i mean this is the big thing for it as well is with this all these galaxies we're going to detect we're going to be able to map the structure of the universe much more precisely you get a map then of where all the matter is but also you get these lensing effects where galaxies bend light from behind them so you can also get a map of where

all the dark matter is that we can't see so that's obviously a huge deal too and then the supernova are going to come into the expansion of the universe you know when dark energy actually started accelerating expanding our universe so a huge range of science goals you know one of those observatories that really is going to have a huge impact across the entirety of the field of astronomy i can't think of a single field that's not going to be affected by the rare rubin observatory i mean astronomy completed it yeah yeah okay so let's get on to some of our listener questions robert carl on instagram asks are there any climate-based issues that could affect future slash near future observations? Yeah, it's a great question, Carla. And the answer is yes. So this has been looked at by some astronomy authors in the context of wondering about the impact of astronomy itself as well,

because, you know, as Becky mentions, when you visit observatories or go to conferences a lot, some astronomers can have quite a high carbon footprint. So conversely, what people have done is said, well, if that happens, if not just down to astronomy, obviously, it's a rather bigger problem than that. But if climate change continues and we end up with a warmer atmosphere and more humidity, what does that mean for telescopes? And the answer is it does affect them a bit. It does make the view slightly less good. It might affect seeing at higher altitudes and it might add more water vapour to the atmosphere. And that can be a bit of an issue because it blocks some infrared light. So it would lead to a decline in the quality of observations you can make. So it is something people are thinking about in terms of where they site telescopes to.

Oh, OK. And Becky, probably on Twitter, asks, could neutrino observatories be used to observe the interiors of super dense objects such as neutron stars? So first up, let's have a bit of a lesson. Let's remind everyone, what are neutrinos? All right. So neutrinos are incredibly light particles, some of the most abundant particles in the universe that have mass anyway. And they're produced every time you fuse nuclei together. So for example, in the sun, when it fuses hydrogen into helium, you produce a load of neutrinos, something like 100 million neutrinos per second

pass through your body from the sun. Yeah. It's insane. Or you can produce neutrinos when atoms break apart as well. So say in a fission reactor, you know, a nuclear reactor on earth that's producing power for us,

or radioactivity. So for example, a banana with potassium will produce neutrinos just willy-nilly or they're also produced though in the extreme temperatures and densities of neutron stars and particularly neutron star mergers so when you have two neutron stars orbiting each other and eventually they spiral together and merge um so this is why i really liked this question probably on twitter thanks Thanks for this. Because I ended up doing a little bit of a dive and I found a paper by Casanato and collaborators from 2011 who looked at estimating the neutrino flux from a binary neutron star merger.

So essentially the amount of energy you're getting in neutrinos when two neutron stars merge and found that it was 10 to the power 46 watts, which if you compare that to the sun's energy from neutrinos of 10 to the power of 24 watts blimey so it's about 46 to the power of 24 that's 22 orders of magnitude larger energy of neutrinos when you start on there so it's god it's 10 billion trillion times larger the amount of energy in neutrinos so yes in a way we kind of could detect neutrinos with such a high flux neutron star merger the problem is we're most likely to detect

them in distant galaxies and then they're really far away because those neutrinos are pushed across a very large area the more they travel the thinner they get spread and so by the time they reach earth you know you're detecting like a neutrino, which is very, you know, very, very unlikely. But if it were to happen in our own galaxy, which is unlikely given just sort of the timescale, what these events actually happen at, seeing it in our own galaxy when we actually happen to be looking at

is very unlikely. But if that did happen, then we'd probably get something like tens of thousands of neutrinos. Or maybe if it was in a nearby-ish galaxy, something like the LMC or Andromeda or anything like that, then a few handful, maybe 100 or so neutrinos from that sort of 10 to the 46th magnitude of energy and neutrinos.

So that would actually be possible for some of the next generation neutrino observatories to detect. So Hyper-Kamiokande is in the construction in Japan at the minute, and that's due to start taking data in around 2027 as well. It's essentially a big tank of water, very, very pure water. Neutrinos come in, hit the electrons or the atoms in the water, and then that actually causes this big cascade of light, which then we can detect. And you can triangulate the direction the neutrinos come from ish you know it's not too bad it's about a five degree accuracy on the sky which is good enough if you found say a supernova

from you know the virarubin observatory which is also quite light as well yeah or say you've got a gravitational wave detection from ligo if you're getting it from a similar patch of the sky, then you know that's probably what it coincides with. And so people are quite hopeful that we might start to take neutrinos from some of these mergers as well. Well, there we go. Great question from Probably.

And Robert, we've had another question on Instagram. This person wants to know, do you think we'll ever get an actual image of our Milky Way as a whole? This is like the classic image in science fiction films isn't it looking at this unfeasibly quickly rotating spiral galaxy from outside but the answer is much as it would be incredible I think I doubt it you'd have to travel well hundreds of thousands of light years maybe half a million light years away to get the kind of view of the whole galaxy and look back at it, which would take a very, very, very, very, very long time.

And even if you could do that, the interesting thing is the galaxy, because the surface brightness is not huge. I mean, it's the same as the Milky Way in the sky. It might not be quite as dramatic as you think. I think you'd mainly be looking at a very black universe with faint patches of light where the other galaxies were. Looking back to the Milky Way, you know, it would cover a lot of sky, patches of light where the other galaxies were looking back to the Milky Way. You know, it would cover a lot of sky, but it wouldn't necessarily be quite as dramatic as you'd think. But what we can do is map it from the inside, which is what we're doing.

That's how we know the shape. So one of the earliest ways that was done was by using radio telescopes, looking at neutral hydrogen emission, and they mapped the spiral arms. I think that was in probably not long after radio telescopes started to become very serious probably 1950s 1960s around that time and now we've got missions like gaia as well because they're producing such accurate maps of the positions of stars we're getting that handle on it too and then of course we've also done things like measure the distance to the center of the galaxy so we build up a picture but that kind of classic view from the outside now i think you're going to have to wait for some unfeasible technology that allows us to travel that far for that to be possible.

Hey, we'll get there. We'll look forward to it. I'm like, no. And there's another question here, not from a list, well, technically a listener, but more of an editor, is Richard Hollingham. So editor Richard wants to know, would we ever get an observatory on the moon?

Obviously the current telescopes on earth are in some of the most remote locations, but nothing gets more remote than the moon. At the minute anyway. Yeah, I mean, moon's great for something like a radio observatory, especially, you know, they're not as, I don't know, construction wise that heavy as something else.

Like we just heard about the SKA is just a bunch of Christmas trees, right? In terms of like the feasibility of it, I guess that would be the most easy thing. I've had questions before about if you'd put something on another planet, say Mars, again, you're getting really remote. Logistics aside, with Mars, you obviously have different absorption of light through the atmosphere. So that obviously presents its problems as well. But there are plans to put like you know we talked about lisa the gravitational wave detector that's the next stage which is a space-based gravitational wave detector that's across earth's orbit so people are talking about you know the logistics of can we actually get stuff into space and so if we're talking about future missions back to the moon as well with

artemis you know will we get in a point where we can actually, you know, plonk down some radio antenna and get a radio telescope on the moon perhaps? I mean, it would only be worth it probably if you could then combine it with other telescopes on Earth to then make, you know, like a telescope the size of the Earth-Moon distance. Yeah, exactly. What about you, Robert? What do you think of this?

Yeah, it turns out there was a conference quite recently on this at the Royal Society, not us, but the Royal Society. And they considered this very question. And one of the proposals was actually an owl telescope, an overwhelmingly large telescope, 50 to 100 metres across on the moon. Yeah, I mean, the challenges are obvious, aren't they? Getting people out there. Would that be optical? Optical, yeah. Wow.

Imagine trying to do that with robots, you know, getting people there. Really hard stuff. But the idea was to do things like, yeah, obviously to have that kind of platform that's outside the Earth's atmosphere entirely and to do things like look for the signatures of life around other stars. But, yeah, it's being discussed. Whether or not it happens quickly, I don't know. I mean, you had pledges. But yeah, it's being discussed.

Whether or not it happens quickly, I don't know. I mean, you had pledges. I mean, when we were talking about things like the impact of Starlink and the impact of satellite constellations on astronomy, Elon Musk was casually tweeting about putting more telescopes in space. Well, you know, it's not a trivial thing to do. We look at how hard JWST was and let alone building the Moon. But in theory, absolutely, it could be a brilliant platform. It's just the feasibility of getting people up there,

assembling it, maintaining it, all of those things that come with it see i'm obviously thinking too small i was like you need to be pitched to be on the team for this astrophysicist and nasa astronaut i think oh gosh no i think i'm good with my feet on the ground okay well thank you, everyone. And if you want to send in any questions to us for a future episode, then email podcast at ras.ac.uk, tweet at Royal Astro Sock, or slide into the DMs on Instagram at supermassivepod.

So, Robert, what can we see in the night sky this month? Well, we are in the middle of the summer. You know, I was thinking earlier, actually, by the way, the one additional size of telescope you forgot to mention was there was a proposal for an overwhelmingly large telescope. You need to add to the list, I think. But however, to get back to the subject at hand, we are near the solstice in the Northern Hemisphere.

And in the Southern Hemisphere, too, it's just wintry there. So that means it doesn't get properly dark up here if you're this far north because the sun just never gets very far below the horizon but if you're up in the shetland hours they even have a name for it they call it the simmer dim because it's always twilight all night so what that means is that you're a bit restricted in what you can see at night on the other hand it is a really good time to look at the sun and safely and i can only put that in bold in the script and i can only emphasize if you're looking at sunspots on the sun do it safely get a professional filter that you order from a reputable supplier think about how you do it there are lots of guides but

do not do not do not do not look at the sun either staring with your eye or staring through a telescope or a pair of binoculars because you will damage your eyes however if you do it safely you should start to see particularly this year as the sun is quite active lots of sunspot groups and we're seeing a lot of those at the moment and associated displays the northern lights which is great now in the not quite night that we've got we can still see most of the stars and planets that in most of the bright ones it's just the fainter stuff you lose and over in the west you'll see venus is really really dominant in the evening sky right through from june into the end of july and as the the month progresses through June if you look at it with a telescope you get to see it changing its phase as well and that's because it's between the earth and the sun so we see some of

the night size and it will change from being about half lit down to a crescent and as it does that it's actually getting closer to the earth and so it'll appear bigger as well. Now you won't see ever really see a lot of detail on Venus, but the phases are really quite beautiful, and it's really something to enjoy with a small telescope. Now, despite the absence of complete darkness, there's a nice conjunction on the 2nd and 3rd of June. There's Mars moving in front of the Precipi open cluster. You need to look for that about 10.30 in the evening, I think, from the UK over in the west. Get a pair of binoculars for a good view. Mars is a long way from the Earth now and quite a lot fainter, it should still be obvious and it's so you've got this red dot hanging

in front of this star cluster and then about the same time of night later in the evening you start to see the summer triangle which is really really its best later in the year but it is there now and i was thinking about other things you can see when it's not quite dark and another good example with a small telescope at least is binary stars and double stars. And these are, if they're binary, it's where stars are orbiting around each other. And a real classic is near the bright star Vega. It's called Epsilon Lyrae.

Good to get a star chart or look online to find where it is. This system is actually made up of at least five stars. And you can see four of them with a telescope. These are two binary stars, which themselves, two pairs, which are orbiting around each other. It's really quite a pretty system, and it's a great thing to find. And another one near there as well, if you look up overhead in the late spring sky and the early summer sky, you've got the plough overhead, the Ursa Major, and one of the stars, the tail Mizar, you can see it as two stars, Mizar and Alcor, with your eye. And if you look with a

small telescope, one of those splits into two as well. So those are things to look out for. I mean, I can't possibly list them all, but they're great objects for this time of year. Amazing. Well, I think that is it for this month. We'll be back with another bonus episode in a few weeks. And then next, it's all about the history of astronomy, how we came to understand the universe and our place in it. Yeah, I'm excited for that one. And get in touch if you have any questions for the team. It's at Royal Astro Sock on Twitter. You can email your questions to podcast at ras.ac.uk or you can find us at supermassivepod on Instagram and we'll try and cover any questions you send in in a future episode

or maybe even a bonus question episode as well. But until next time, everybody, happy stargazing.