Tim Panton: I'm Tim Panton and this is The Distributed Future podcast, where we talk to people who are doing interesting things who maybe can tell us a little bit about what the future will hold. I encourage people to bookmark this, favorite it, comment on it, spread the word because otherwise, people don't learn about this stuff, and a lot of it is either interesting or important or just fun. So, I'd like our guests to introduce themselves now and then we can get going.
Samantha Lawler: Hi, I'm Dr. Samantha Lawler. I'm a professor at the University of Regina in Saskatchewan, and I study the orbits of Kuiper Belt objects-- these are small icy bodies in our solar system-- and use that to learn about how our solar system formed and evolved over time. But lately, I've been focusing a lot more on the orbits of Near-Earth satellites, so low-Earth-orbit satellites that are in more and more of my images, and I see more and more in my night sky. So, yeah.
Tim: How small are these Kuiper belt objects? When you say smaller, is it millimeters or inches or...?
Samantha: Oh, no. I'm talking about things like Pluto, right? Pluto is the biggest Kuiper Belt object, just slightly bigger than Eris, which is more massive than it. But most of the Kuiper Belt objects that we study are 100 kilometers across or bigger. That's kind of the range.
Tim: And they're kind of edge or solar system so you're looking relatively long way out and you're observing from the ground?
Samantha: Yes, yeah. Most of my observations come from the Canada-France-Hawaii telescope on Mauna Kea in Hawaii. So yeah, we're looking through the atmosphere through any satellites that are orbiting over us through the solar system and looking for light that is reflecting off of these tiny icy bodies on the outer edge of the solar system.
Tim: And are they quite... I mean, given that it's ice, is it quite reflective, or you're really searching for them?
Samantha: Oh, actually they're surprisingly dark. Most of them are very, very dirty. So we talk about icy bodies, but it's really dirty old ice. Like here in Saskatchewan, we're finally getting into spring and the nasty ice that you see on the sides of the road that's super dirty and gross, that's kind of what I think of for these icy bodies. [chuckles] They're not pristine white ice, they're actually pretty dark. So, it is challenging.
Tim: Maybe now's a moment to bring up that scientific term which I did know and I reminded myself of when I was reading up on what you're doing. It's 'albedo', which I think is a wonderful word. I don't know what the derivation is, but it's lovely.
Samantha: Yeah, so basically it just means reflectivity, right? So, an albedo of one is like a perfect mirror that reflects all the light back at you, and albedo of zero is a perfect blackbody that absorbs everything.
Tim: And it seems to be a thing that crops up a lot in astronomy, because it's a thing that you really care about. Like how hard it is to see the thing you're looking at.
Samantha: Yeah, so the typical Kuiper Belt objects that we look at are something like 5% albedo, right? So they're really quite dark.
Tim: Right. And that's a kind of dark grey to black in web terms anyway. So yeah, interesting. But if I understood correctly, your observations are much more difficult than they used to be because you're getting these Starlink and other satellites, but presumably mostly Starlink satellites in your images. Is that a new thing or has it always been a problem?
Samantha: There have always been... I mean, as long as I've been observing, there have always been a few satellites. So the observations that I'm doing because we're trying to find these very tiny, very dark things in the outer solar system, we use long-time exposures with very big telescopes. So the telescope I use has a four-meter mirror. That's quite large. So we stare at one spot on the sky for five minutes, and so all the light from the stars builds up on the telescope during that time. And if any satellites fly through, they appear as a bright line going across the image. So they don't just cover up a few stars, they cover up a whole line of stars. And if they're really bright, that can cause other problems because these are very sensitive cameras that we're using, right? The typical Starlink satellite that flies through the field is millions of times brighter than the typical Kuiper Belt object I'm trying to find. So it's a huge contrast. And when we get more and more of these streaks, there's less and less of the field of view that we can search for Kuiper Belt objects, which means that we need more time to do the same science. So it's directly making scientific discoveries with publicly funded instruments harder because of the actions of a for-profit company.
Tim: Yeah. This is kind of interestingly reminiscent for me many, many, many years ago, my sole relationship with astronomy is I did some software for ISO's ISO Space Telescope-- the infrared. And one of the things that they [crosstalk]
Samantha: [crosstalk] actually, for my undergrad research project. Yeah.
Tim: Yeah, cool. The thing with ISO was because it was infrared, it had the same problem you're talking about; it began getting supersaturated. But it could actually be damaged by... I mean, you obviously with an infrared telescope you can't look at the Sun. But you couldn't look at the Earth or the Moon or even Mars. So a lot of the software we were writing was to do with trying to schedule the things so that we could observe the things, or rather the scientists could observe the things they wanted to observe without ever getting any of those super bright objects are hot objects into the field of view. Because you could literally wipe out one of the instruments with that. So yeah, that was a real... It's kind of interesting to be... But you don't have the option of kind of... Or you are, I don't know maybe if I understood you correctly, you're kind of narrowing the places you look to maximize the avoidance or what?
Samantha: Not yet. The satellite problem is not bad enough yet that we need to optimize to avoid satellites, but it's getting close. The Vera Rubin Observatory, which is going to be an all-sky survey from Chile, which has had a huge amount of-- especially US taxpayer money put into it-- billions of dollars. This telescope facility is scheduled to come online in the next year, and so the satellites are going to be a huge problem for it. So they are actually thinking about how to optimize their pointings to avoid satellites. So they will get less science out because they're having to optimize for a totally different source of noise, right? And the reason for that is because these Starlink satellites, in particular, are so bright that if they fly right through the field of view of this telescope which is even bigger than the one that I use (it's an eight-meter mirror) with one of the most sensitive cameras that's ever been built attached to it. So if the Starlink satellites fly through, they're so bright that they'll actually wipe out not just a line across the field but they could actually destroy the entire exposure, so that whole exposure would be lost. There are ways to avoid the satellites, but it means that you're not going to have your main science goals carried out as quickly. So certain times of day-- sorry, certain types of night rather-- there are more satellites in the sky and certain areas of the sky, and you can even go so far as to look up when individual satellites are going to fly through a particular field of view and try to avoid them. But all of this requires more engineering and more computational resources to carry out the same science that could have been done without all of this; without these extra satellites.
Tim: So maybe we need to step a little bit back and think about understanding what the physics of the situation is. I mean, we're talking-- I've forgotten the numbers, but thousands of satellites covering... I mean, what's the pattern? What's their coverage? Are they kind of in a ring, or is it an entire sphere, or how is it like?
Samantha: I just looked up the numbers right before we met, because there was another Starlink launch yesterday, right? Starlink is launching batches of 60 satellites every few days right now. So there are currently 3,968 Starlinks in orbit out of 7,578 total satellites. Starlink is now 52% of all satellites, which is why I talk about Starlink so much. They effectively control orbit now. [chuckles] So they're the company to worry about if this is causing any problems. The way that the satellites are distributed... The whole point of these satellites is to get internet in rural and remote locations, which as someone who lives on a farm quite a ways outside the city, I understand how hard this is. My neighbors have Starlink internet so I understand, especially during the pandemic where everybody's been working from home, I understand how important this is. So my point is just to keep coming back to the fact that if there was better engineering of these satellites, we could have internet and astronomy. It wouldn't be as big of a problem. But the point is to provide internet, so the satellites are distributed around the globe as much as possible. They follow these tilted orbits and so if you take a whole bunch of these orbits that are tilted with respect to the equator, and sort of imagine you have your fingers encircling a small imaginary globe, right? You're around the equator, tilt your fingers upwards so that you have sort of a tilted circle around the Earth so that the top of the circle goes over maybe Vancouver and the lower part of the circle goes over somewhere in South America, right? Now, make a whole bunch of those little circles and sort of turn them around. And so what you get is these bends of satellites around the Earth. And where they have their highest latitude and their lowest latitude passes is a higher density of satellites, just because they spend more time there.
I made a model of this because I was curious, I wrote a paper about this with a couple of other astronomers looking at where the satellites are predicted to orbit, and it turns out where I live at latitude 50 degrees North is actually one of the worst places in the world for satellite passes. There's just so many Starlinks over my head just because of the orbits that the company has chosen to get good coverage around the world. So that's another choice that a company has made that makes it particularly bad where I live, [chuckles] which is really annoying. So, yeah.
Tim: Again, maybe just probably back to the basics of this. The trick, which I guess started with Iridium, was originally communication satellites were geosynchronous; they were a long way out and they were always pointing at a relatively fixed point on the globe. And so they were utterly predictable and they were very few of them, and they were expensive and whatever. And then Iridium came out with this thing, which must have been 66 satellites that did this handover kind of the reverse of a mobile phone base station, like the base stations moving in your stationary but it hands over from one to the other. And I think they were the first people to do that, and then Starlink's just taken this same constant movement thing and hand over thing and really turned it up to the max, as you say, with three and a half satellites. I wonder how many users they've got per satellite. I mean, it's probably hundreds of users per satellite or something. I don't know.
Samantha: Yeah, that's a really good question. I don't know. They want to have 42,000 satellites, right? Which is just a stunningly huge number of satellites.
Tim: That's another factor of 10.
Samantha: Yeah. Over any number of satellites that we've ever had in orbit. That is more satellites than have ever been launched before and they want to have them simultaneously all operating at once. And they're in such dense orbits that they actually have to actively avoid colliding with themselves. They're all in one shell and they're on these criss-crossing orbits all the time. And so far they're doing a great job, they say that they've got this autonomous collision avoidance system, and whenever there is a-- so, conjunction is the closest approach between two objects, right? So whenever there is a conjunction with a collision probability of one in a hundred thousand, they will maneuver to avoid the collision to bring the probability down. I think the standard is one in 10,000. So they're actually being 10 times more cautious than they need to be. But with so many in orbit, when they move one satellite away from that potential collision, it's now in orbit with a different potential collision, right? So the number of collision avoidance maneuvers that they are doing is increasing dramatically. Hugh Lewis is a professor at the University of Southampton, I believe, and he studies this. He had posted on social media recently that Starlink did more collision avoidance maneuvers in March of 2023 than they did in all of their previous operation history. Like, as they add more and more satellites to their constellation, they're constantly having to shift them around. And they're doing a great job of it now but how long will that continue for? We're coming up to solar maximum, and so as we get more and more solar storms in addition to getting beautiful auroras, this can cause problems for satellites. Satellites have been shut down in the past, so what happens if a bunch of Starlinks get knocked out by a storm and they can't avoid colliding with each other? This is something that I worry about a lot. I have asked people who work at different satellite companies and they have never had a good answer for me. They're just, "No, it's fine. We don't have to worry about it. It'll be okay. Don't worry about it."
Tim: So tracking back a little bit, we say avoidance and I have a kind of picture in my head of little rockets firing, but is that how it works? Or is there some kind of angular momentum trick you can play? Or how does that... What I'm trying to get at is that is it a limited resource.
Samantha: Yeah. I am not a satellite engineer so I'm not 100% sure how this works but I believe that they do have propellant onboard the Starlink satellites and they use that to change the orbits. So that is a limited resource. And that's another thing that worries me about Starlink in particular, is that all of the satellites are designed to have a lifetime of five years, which is not very much. It's great for them because they can change out old technology for new technology very quickly, it means that it's not a big deal if they lose a batch of satellites because of some mistake, but it means that they're planning to de-orbit and resend their entire constellation of 42,000 satellites every five years. If you do the math on that, that comes to 23 satellites per day that they have to be launching and burning up in the upper atmosphere. And that mass of those satellites doesn't go away, it gets added to the upper atmosphere. And it's mostly aluminum, which is not something that naturally happens in the upper atmosphere. There's a huge amount of meteorite material that is added to the upper atmosphere every day, but it's mostly rock, right? It's mostly silicates with a very small fraction of aluminum. So the newest Starlink satellites are supposed to be 1200 kilograms each, right? This is like the size and almost the mass of a Ford F-150. These are big satellites. And they plan to destroy 23 per day in the upper atmosphere. That's many tones of satellites per day in the upper atmosphere. It's crazy. It's crazy. This is their actual plan.
Tim: I'm seeing a future business in scooping them up before they land and reselling the... Actually, I realize now I've stolen that from a very strange Korean Sci-Fi movie I watched the other night, which is about rescuing... But anyway, whatever. So that's a lot of stuff. And aluminum will burn, which presumably changes the way it will... Like, instead of turning... I guess the silica is turned into sand and fragments, whereas aluminum will catch fire, I guess.
Samantha: Yeah. And there's chemical reactions that will happen. The upper atmosphere is a very different place than we're used to thinking about. There's very specific chemistry that happens up there. Like the ozone layer, that's really important. What is adding many tonnes of aluminum per day going to do to the ozone layer? Nobody's really studying this right now because low-Earth orbit is not considered an environment legally so there's no environmental assessment that needs to be done for that.
Tim: I was gonna say this begs a whole question about regulation and whose space is it, and whose rules apply? It's sort of like the International Law of the Sea. You know, what's the international law of low Earth orbit?
Samantha: Yeah. So there's a treaty and an agreement from the Space Race era; [laughs] the Outer Space Treaty and the Space Liability Convention. And that's really it. These were written in a time when the only launchers were governments, right? So they apply only to governments, it's not even clear if they apply to private companies like SpaceX. Yeah, there's going to be a test of this very soon. Like, what happens when a SpaceX rocket crashes into somebody's house in Brazil? Legally, we have no idea. The only time that any of this has been tested legally was when the Soviet Union crashed a nuclear-powered satellite into Canada in the late '70s. And what ended up happening was the Soviet Union paid Canada some piddly amount of money for a cleanup fee many years later. But yeah, we don't know what is going to happen. Because there are-
Tim: -But that was the government.
Samantha: Yeah, that was between governments. You know, pieces of SpaceX rockets and Chinese rockets have been falling in places in the world. And there aren't any casualties yet, but it's really only a matter of time. So yeah, this is something that I am watching with fascinated horror to see what will happen. Space law is an area that will be growing very rapidly in the next couple of years. [chuckles]
Tim: So where do you think... It's always interesting to try and work out where that movement might come from. Where might people start to regulate this? Is this something that the EU cares about? Is it something that the Chinese government would want to try and care about? Is it the United Nations? Where's this movement gonna happen?
Samantha: I think I think it has to be at the UN level because this is every country. I live in Canada, I've talked to the Canadian Space Agency and various representatives from Canadian government about these issues of satellite pollution. And if I convinced the Canadian government to have Starlink, for example, pay for damages, right? Pay for environmental damages, or pay for astronomy damages, right? Like, "Your operation is making astronomy harder in Canada so you need to compensate astronomers because they're not getting as much science out at the same amount of time." Right? So Canada could do something like that. That's a classic solution to pollution issues. But then Starlink could just turn around and say, "Err, the Canadian market isn't that big anyway, we just won't broadcast to you." So then we would get all of the downsides and none of the benefits. [laughs] That is the worst possible situation. So any regulation has to be international. Otherwise, you just get flag of convenience states and all these satellites would operate out of some small country in the Caribbean or something like shipping does now.
Tim: Is it like thinking about how the Freon changes happened? Like, how was that negotiated? I mean, I'm asking you to comment on stuff that's way out of your academic area but, you know? [laughter]
Samantha: So that was a huge... Many states and many governments came together and signed an agreement to phase out Freon, right? So there has to be something like that. And I know that there are discussions happening about this at the UN level, but it's very slow. And meanwhile, Starlink is launching 60 more satellites every week or two. So they are not keeping up with the speed of business. I don't know. What I encourage people to do, the one thing that can move fast is consumer pressure. So, this is a for-profit company and, you know, I talk a lot about Starlink because they're the first but there are many companies lined up to do the same thing. So, tell them. This is an engineering problem. They have shown with a couple of mitigations that they've added to some of the satellites that they can make them fainter. They can, if they make it a priority, to try to use fewer satellites or to try to use different materials on their satellites. I have no doubt they could do it. SpaceX has some of the best engineers in the world, they do amazing things. So I have no doubt that if they made it a priority to make their satellites less polluted, they could do it. But right now, that's not a priority. So if they were told that's a priority, then they might change that.
Tim: So what you're saying is there's no downside from their point of view. There's no reason why they would reduce the albedo or change or whatever, because it doesn't cost them anything and not even bad publicity, except that we're kind of adding to that now.
Samantha: Yeah, exactly. And most people don't notice this change. I'm one of the few people in the world who see it, both in my telescope data and with my eyes. I'm really fortunate to live on a farm, it's really dark, I can see the Milky Way from my back door. And I really, really am grateful for that. But because I live in latitude 50 degrees North, I see the worst of this pollution from satellites. So it is impacting my job and also my enjoyment of the sky. Probably most people would not have as strong of a reaction as me but every time I see a satellite, it makes me very angry just knowing what's happening, what's coming, and how it could be better with better engineering. But right now, it's just a race to get as many satellites up there as possible. So it's just not being done well.
Tim: Yeah, I think it's interesting to reflect on the night sky and its influence on well, frankly, our civilization. And when I went to a really, really lovely exhibition of Aboriginal art in song lines in-- actually it was in Berlin surreally-- but that was fascinating. And a lot of that was about how entire communities were telling stories about the night sky. And because they all saw the same night sky even though they were spread out over 1000s of miles, those stories related to the constellations and so it was almost like a cultural glue that they had in common between them, which is a fascinating idea that that spread out over 1000s of miles in this same sky view. And the similar thing with navigation: Historically, if you read Hornblower or something, all of those early sailing novels, they're all about you know, "Can we get a view of the sky tonight to work out where the heck we are?"
Samantha: Yeah, exactly. So here in Saskatchewan, the indigenous people have used the constellations to know what food to look for, what season's coming up. Like Ojibwe, there's the moose constellation. So when the moose is rising, the moose is powerful and you should go hunt the moose. And when the moose is setting, the moose is weaker and it's not as good of a food source. There's so much knowledge encoded in the sky that we've had for 1000s of years. And this is humans looking at patterns and using that to make predictions about the future. That's exactly what we're doing in astronomy now! We look for things like potentially hazardous asteroids, right? And we measure their orbit very carefully and we know is it going to come back and hit us? Or is it going to come back and miss us? And that's one particular disaster that we can do something about that now if we have enough warning. But near-Earth object detection in particular is made much harder by satellite pollution. [chuckles] So it all comes back to that.
So, the calculations that I have done for trying to figure out how bad could this light pollution get; so I took 65,000 satellites, which is for different companies on the orbits that they say they want to use, and calculate how bright they should they would be in the sky. And I calculated that one out of 15 stars in the sky would be a satellite. Can you imagine looking up at the sky and all the points of light that you see, one out of 15 of them is moving. That's horrible to think about. But we're getting there. That's what we're heading toward with no regulation. So yeah, it really makes me feel ill to think that that might be the sky that my kids grow up with.
Tim: It's a different sort of experience. It's no longer a constant thing which you can draw certainty from, because it's a much more mobile thing, which is kind of... And I suppose it's still predictable if you can do the math, but not in the same way.
Samantha: Yeah, and it's amazing engineering. I hear a lot of people say, "Oh, well, I just see the satellites and I think of all the great engineering that's gone into them," and like, "Yes, yes, it is really impressive engineering." But beyond those satellites are giant black holes and exoplanets and potential life, right? There's so much beyond that, how can we enclose ourselves in this cage of human engineering and not look beyond it to them much more amazing things out there? That's a little horrifying.
Tim: Yeah, my theoretical physicist friends always treated the rest of the universe as their laboratory. Like, if you got a theorem to prove, you go off and you can't build it at CERN or wherever. You go off and you look for an experiment that's happening somewhere out there in the universe and watch it. And their whole careers have been built like that of just spotting a particular behavior from a red dwarf or whatever it was. I suppose what you're starting to see, and with ISO and the James Webb telescope and that, we're starting to see telescopes move off the ground and be actually probably outside this shell of low Earth orbit. Is that the only way that astronomy's going to make it through this crisis, or do you think there are other ways that that can be done?
Samantha: Oh, there is definitely. Space telescopes are great for some types of science, and for some types of science, you can only do them from space. I don't know if you've seen, I'm sure you've seen some of the pictures from JWSD, it is incredible! It's just completely mind-blowing the images that are coming in from that telescope. But that was a $10 billion telescope that is not even in Earth's orbit. It's an Earth trailing orbit so it's not even in orbit around Earth. So the Hubble Space Telescope, most space telescopes are in the same orbit as Starlink. There was actually just a research paper that came out a couple of weeks ago that talked about all the satellite light pollution that the Hubble Space Telescope is getting now. Because it's the same orbit. Yeah. So you have to get completely out of Earth's orbit to get away from satellite pollution, and that is a many-billion-dollar proposition. And I don't see any of the satellite companies coming to hand us billions of dollars to do that. Ground-based telescopes will always be cheaper, will always be bigger, will always be easier to fix, and they're just so much more accessible.
Tim: Yeah, Hubble's a real case in point for that.
Samantha: Yeah. Yeah, exactly. So it's not the solution. [chuckles] I mean, our eyeballs are the best observatories. For any of these large ground-based telescopes, I think that astronomers will come up with software solutions and hardware solutions to work around satellite streaks, but there's no mitigation strategy for your eyeballs. If satellite companies could engineer their satellites to be fainter than you can see with the naked eye, I would be very happy. That also means that they'll be faint enough that they won't cause huge problems for ground-based telescopes.
Tim: So you still get an occlusion there, but you wouldn't get the blast of light.
Samantha: Yeah, exactly. You wouldn't see these dots moving across the sky and super bright streaks in your longtime exposure images if the companies could prioritize making them faint. And that was what Starlink initially said they were going to do; visual magnitude seven is what they said, so six and a half. So, magnitudes are backwards and logarithmic so six and a half is about as faint as you can see with your naked eye. Something like four or five is a star that you can see from a light-polluted suburb. One and zero are the brightest stars in the sky. So Starlink satellites right now are typically four to five. There are some Starlink satellites that they put visors on that are down around six and a half. They got it down to six and a half, which is amazing, but the newest ones don't have the visors anymore so we don't know how bright they're going to be. Astronomers are waiting to see. They've launched the latest batches and all have no visors, and they're much bigger. They're supposed to have some kind of coating on them that makes them darker, but Starlink is not testing this, astronomers are testing this from the ground for Starlink. But I'm glad that they're still trying to make them fainter. I think this is a tractable engineering problem but we just have to wait and see. We don't know until they're in orbit, right? They don't share this information beforehand; you just have to wait and look.
Tim: Right. Interesting. It's like black anodized aluminum rather than shiny aluminum or something like that might be a workaround that would make a big difference.
Samantha: Yeah, and they're working on very interesting, highly engineered different types of coatings and different... Again, I'm not a satellite engineer so I don't know exactly the specifics of it, but I know that they have put some effort into this and I'm very grateful for that. I'm glad that they haven't completely given up. I was quite worried when I heard that they were not going to put visors on any of their satellites. So yeah, the visors made them much fainter but they didn't quite get down to that magnitude seven. If they get down to magnitude seven, that's faint enough that you can't see it with your eyes and it won't cause problems for really big telescopes like the Vera Rubin telescope. There'll be streaks, but it won't completely obliterate entire exposures.
Tim: Right. What would be good is if that best practice would be something that was somehow either financially or regulation-wise encouraged. And it's funny with the podcast, we keep coming back to these kinds of, you know, how do we encourage good behavior when there's no financial incentive? We've had endless gloomy discussions about AI on that basis. Like, what is the economics of removing bias from Ai? How do you persuade people that it's economically necessary? And the answer seems to be a combination of peer pressure, actually, and regulation. And you kind of need both somehow.
Samantha: Yeah, and that's what we need for satellites. Yeah.
Tim: It's funny. It's the same sort of, as you say, incentives not being there. That's the problem. You need to provide incentives that allow the engineers to do the stuff that they probably quite want to do anyway, it's just that they don't have the budget for it because they're not compelled to. We all know that feeling, [chuckles] or I think we all do anyway.
Samantha: Yeah, exactly. Yeah. So Starlink has done a fair bit of work, they could do better. They could do much better on making the satellites fainter. But there's many other companies lined up to do the same thing. There was one company AST Mobile that launched one of the biggest satellites surface-area wise, one of the biggest satellites into low Earth orbit. And yes, the space station is much bigger, but there's only one space station. Well, I guess there's two, there's the Chinese one also. But that's not a big deal because there's only two of them. So AST Mobile launched a satellite that the antenna area is the size of a tennis court, so, way bigger than Starlink satellites. And it was measured by astronomers to be as bright as the brightest stars in the sky. And they want to launch 100 of them. These are supposed to be for direct-to-phone satellites. So, astronomers had not talked to this company at all and didn't know about this company. It came out of nowhere and just all of a sudden, there's a huge new source of light pollution in the sky. So even if one company-- if Starlink does it, that's great because they have the most satellites, but there's a lot of other companies that can still launch many, many satellites and cause even bigger problems. So there has to be regulation and peer pressure like you said, consumer pressure. These companies are all for profit, so if consumers tell them that keeping the sky dark and keeping the orbit safe are our priorities, then they will follow that. Right?
Tim: I wonder, to what extent the kind of peer pressure from the engineers is also encouraging engineers that this is something that would be good if it was done is a way of getting things to change. I mean, to some extent we've seen that with some other disciplines. In the end, the engineers get fed up with it being sexist or whatever and just say, "We rather have a decent working environment for all that that's maybe not exactly what the company is after." And it starts to impact recruitment and stuff like that. I think that's maybe a bit tenuous in this case, but we can imagine that it might happen if one was optimistic.
Samantha: The light pollution issue I think is one that would be a hard sell for... A lot of people haven't noticed this change in the sky, right? Most people live in very light-polluted places, urban light pollution, so you wouldn't notice that there are now dozens of satellites that you can see in the night sky every night. But urban light pollution you can get away from, right? The satellite pollution-
Tim: Yeah, I was gonna say... A little little plug here, I strongly encourage everyone who's listening too to go and look up dark sky, and go and find their nearest dark sky area and go out on a cloudless night and just see how many stars there are out there. We did this here a few months ago and it's just amazing. You forget when you're surrounded by city lights or whatever that actually once you get probably only a few miles out, and if somebody's made a little bit of an effort to find a quarry or something with very little light, it's just amazing!
Samantha: Oh, it's incredible. It's incredible! And then just knowing- [crosstalk]
Tim: We live there so, you know, [unintelligible] [laughs]
Samantha: Yeah. I studied this for a living and I still get total goosebumps when I look up at the Milky Way and think about every single one of those stars has a planet around it. We know that now. At least one planet. And any of those planets could have life on it that's looking back at us, right? That's crazy to think about. And you just don't get that in a city-- you see a couple of stars. But when you can get out to a dark place and see the sky as we have seen it as humans for as long as we've been human, it's only the last few generations that have lost that. It's just completely incredible. And the satellite pollution, one nice thing about the satellite light pollution is it's only within a couple hours of sunrise and sunset. So if you get in the middle of the night and it's not close to the summer solstice, then you will get a period with no satellites in the sky that you can see with your eyes so it's not completely ruined.
Tim: Right, just because of the geometry of the situation. It's not that there are no satellites, it's just there's no [sunshine] at all.
Samantha: Yeah, exactly. [unintelligible] is blocking any light on the satellites for part of the night. At my latitude, in the summertime, I get satellites all night long, which is really annoying. But at lower latitudes in the summertime, you get some period of time with no satellites. And in the winter, I have a good chunk of time with no satellites so I try to enjoy that. [chuckles]
Tim: So outside the Starlink situation, what's your research covering? What are you looking at these days? And you know, what's fun? What's exciting? What should we know about?
Samantha: Yeah, right now I am co-leading a big program on the Canada-France-Hawaii telescope looking for new Kuiper Belt objects. We're trying to find the smallest and most distant Kuiper Belt objects in these-- we call them sort of pencil beams. So you're looking through the solar system and trying to find everything in this one little narrow spot. So we're looking for tiny Kuiper Belt objects which will tell us about how planets formed. So the New Horizons mission which flew past Pluto and then flew past the small Kuiper Belt Object, Arrokoth... Arrokoth surprised everybody because instead of being a nice round planet, it looks like a snowman. It's like two small things stuck together. It's just bizarre. Nobody expected that! And that has completely changed the way that astronomers think about how planets form, and has sparked a whole new set of simulations for how do you get those first solid bodies in the solar system? And so we want to find more of those and try to figure out if they're shaped like Arrokoth. We'll have to do this just by watching how the brightness changes over time, we won't actually see the shape. And how many are there? Because that also tells us about how planets formed. We also want to find the most distant Kuiper Belt objects, which could tell us about whether or not Planet Nine exists.
Planet Nine is this theoretical giant planet that is not discovered yet, and it was suggested because the very most distant Kuiper Belt objects look like they're all sort of pointed in the same direction in the solar system. They have these big elliptical orbits that all point in the same direction, at least the first ones that were discovered. So I've worked on this project for a while trying to figure out are they all pointed in one direction because they're actually all in the same place. Or is it because nobody looked in the other direction? [laughs] And that's a hard question to answer. So one of the goals of this project is to look very carefully in six different directions evenly spaced around the solar system, and try to find a couple of those in each direction. And that will tell us if this clustering is real or not. Hopefully, we'll find some just totally bizarre orbits along the way that will just completely break everything, because that's the most fun part of science is finding the things that you didn't expect.
Tim: Right. Right. That's always the cause, it's everyone to rethink and come up with new theories and then start the whole cycle again of trying to test those theories and work out what's happening. So yeah, that's exciting. What can you tell about these objects apart from their brightness? Do you do get any spectroscopy back from them, or mass estimate or what?
Samantha: Yeah, we can get a size estimate which we can extrapolate a mass estimate, but it's extrapolating an extrapolation at that point, so it's pretty uncertain. They're too faint for spectroscopy the ones that we're going to discover, but we can get their orbits really well. And that's the part that I like, I love orbits. So measuring their orbits over time will probably take a few years of follow-up. We'll have to keep finding them and measuring their positions over and over over the course of probably three or four years, and that will tell us really precisely what kind of orbit they're on. And that's the really neat part for me because I can plug those orbits into computer simulations and figure out how did Neptune have to move, or is there something extra out there that is giving a gravitational kick that can explain these weird orbits that we see? That's the part that really excites me personally. So this is all basically gravity.
Samantha: Yeah, it's all gravity. Yeah.
Tim: Wow. Wow, that's fun. That's exciting, actually. Cool. What we tend to do with this podcast is ask the guest if they will be kind enough to produce some links and then we can put them into the show notes. And then if the listeners want to find out more about any of the stuff we've talked about, at least there's maybe somewhere to go looking for this stuff. But no, that's fascinating. I'm sitting here thinking how does one do this and how do we change things? But on the other hand, exciting to think about these... Actually, how do you know that it's the same one? If you go back and look for it later, how do you know it's the same one?
Samantha: That's a good question. So this will be a problem in this program because we're gonna find a lot of them in each little footprint on the sky. It'll be a combination of making sure that the brightness is about the same, and also making sure that the orbit makes sense. Right? And if we get an orbit that is totally wacky, either we did the measurement wrong or there's something really cool happening and then we need to double-check that. [laughs] So there will be a lot of double, triple-checking to make sure that we are finding the same things and putting them up. Coz yeah, it is tricky. They're all moving at different rates on the sky because they're all at different distances and when we go back a year later to try to find them, they've moved quite a bit. So there is some ambiguity but yeah, physics lets us have a nice double check on that.
Tim: And you're not in any way a quantum physicist. All of the stuff you're doing is essentially Newtonian physics, am I right?
Samantha: Yeah, exactly. It's all all-classical dynamics. I don't have to think about relativity, I don't have to think about quantum mechanics, I don't have to think about electromagnetism. It's just mechanics. I love it. [laughs] That's my favorite part of physics.
Tim: Cool. Anyway, a little digression there. But thank you so much for doing this, I really do appreciate it. If you can pop some links over to me, I'll put them up on the website when this goes live. And yeah, it's been great and fascinating to hear. Thank you so much.
Samantha: Yeah, thanks for having me. And yeah, I hope everybody who listens gets a chance to go out to a dark sky and preserve it. It's really amazing. You won't regret it.
Tim: Yeah. Cool. Thanks so much.
Samantha: Yeah, thanks. Thanks for having me.
Tim: Yeah, bye.