This Week in Space 126 Transcript

Please be advised this transcript is AI-generated and may not be word for word. Time codes refer to the approximate times in the ad-supported version of the show.

0:00:00 - Rod Pyle
On this week's episode. This Week in Space we're looking at rogue planets that wander space until they smack into a planet like ours. Perhaps Join us Podcasts you love.

0:00:13 - VO
Podcasts you love. From people you trust. This. Is TWiT.

0:00:16 - Rod Pyle
This is this Week in Space, episode number 126, recorded on August 30th 2024. Danger Rogue Planets. Hello and welcome to another episode of this Week in Space, the Rogue Planets edition. Yes, it's as scary as it sounds. Well, I think it is. We'll find out. I'm Rod Pyle, editor-in-chief of Ad Astra Magazine. I'm here with the one and only: Tariq Malik

0:00:43 - Tariq Malik
Surprise, surprise, I made it. I made it this week.

0:00:47 - Rod Pyle
The editor-in-chief at space.com, who was supposed to not be with us but at the last minute made it. So thank you for coming, Tariq. We appreciate it.

0:00:54 - Tariq Malik
I'm glad to be here. Glad to be here, ryan as always and with all our space. Fan listeners, of course.

0:01:01 - Rod Pyle
And, as you may have guessed, today we're going to be talking about rogue planets and their implications all that that contains with Dr Rosalba Perna, professor of physics and astronomy at Stony Brook University, and she'll be joining us shortly, but before that, we'd like to ask you once again, as I always do, to do us a solid make sure to like, subscribe and all the other podcast goodies to our podcast, so we can continue to bring you this enlightening information in a way that is so unique to us. Speaking of unique to us, we have another space joke from listener Martin harris, who graced us last week. Are you ready, my friend? I am ready.

Yes, what did orion get when it came last in the race?

0:01:46 - Tariq Malik
I don't know what. What did orion?

0:01:48 - Rod Pyle
get. He got a constellation prize I love it, that's good hey all six of our fans liked it too. Thank you, six fans we appreciate that okay, yes, thank you, martin, uh, much appreciated. And for the rest of you, get on it and send us those space jokes so that you don't have to listen to mine. Okay, so let's do some headlines.

0:02:12 - Rod Pyle
And we'll start with... it's an easy guess: Starliner

0:02:18 - Tariq Malik
Hey, it's coming home. We have a date, that's right. That's right. And finally, at long last, what? Three months after it launched into space, Starliner will return home just after Labor Day weekend. But I guess Boeing found out it's not kosher to wear white after Labor Day, so they're bringing their blue and white space capsule back to Earth. This is obviously from space.com, but everyone else was reporting it too. Space capsule back to Earth. This is obviously from space.com, but everyone else was reporting it too.

Nasa and Boeing have set September 6th, which is next Friday. Rod, right hours after you and I record our next episode, boeing will return to Earth, and so we're going to find out how it all goes, but mark your calendars because you're going to be able to watch it live late Friday night. The action will happen. I think it undocks around 6, and it lands around 12 am on Saturday, so it's going to be a pretty interesting time Coming back empty as well. As we all remember, and in fact NASA just announced who is going to be flying up on Crew-9 and who lost their seats, and right now it's Nick Haig and the Russian cosmonaut who are flying, and that means that Zanuck Hardman and the other crew member will have to wait for their next flight.

0:03:33 - Rod Pyle
So you know it's an interesting contrast. So we've got this Starliner drama going on and again, hopefully they'll get things straightened out, hopefully it'll come back fine. Hopefully this was an overabundance of caution, which is always a good thing, you know, if you're flying people in space, yeah, and hopefully they move forward and they are able to at least fly out their six flights with this thing before the space station is uh, ended. But in a kind of stunning contrast, the same time all this is going on, spacex is flying professional tourists. That's right when to go higher than anybody's gone since, uh, gemini 11 or the apollo program and, um, I don't know, you know, you just look at that, they're not related and I get that. But no, you've got this. The dragon doing yeoman work, uh, very admirably, and, um, you know, hopefully it will continue to keep doing that and I'll let you draw your own conclusions.

0:04:27 - Tariq Malik
I just I saw that and immediately after that I read a Starline article and I thought these things don't transpose well, for perspective, the next launch in September of NASA crew on SpaceX Dragon will be their 10th crewed flight for NASA and I think they've launched four other private flights already with AX one through three plus Inspiration4. So that's a lot, that's a lot.

0:04:51 - Rod Pyle
We'll let that speak for itself. Okay, moving on Speaking of SpaceX, not all is wine and roses. They had a record setting 23rd flight for one of their boosters that I think flew the first crew flight right.

0:05:07 - Tariq Malik
It flew Inspiration 4. It flew Demo 2, I believe, which was the crew flight plus something like 16 or something different.

0:05:16 - Rosalba Perna
But it won't be flying anymore.

0:05:19 - Tariq Malik
No, no no, no, no, no, it is not flying anymore. In fact, on line 22, john, you can see what remains of booster 1062. Not a lot is the message there. Photographer John Krause got shots of it. Coming back on the drone ship, spacex's as you explained, boeing's, not Boeing's I haven't had enough coffee yet SpaceX's most flown booster.

0:05:51 - Rosalba Perna
That was Freudian I tell you Booster 1062.

0:05:56 - Tariq Malik
This was going to be like their big 23rd landing.

0:06:00 - Rod Pyle
There's not much left of that thing, is there?

0:06:02 - Tariq Malik
No, it launched a Starlink mission on the 28th, really early in the morning on the 28th Perfectly. Mission went fine, deployed the payloads, fine, but when it was trying to land, something happened. It looked like one of the leg struts buckled and the thing toppled over. It also looked like it caught fire as well and it just tipped on its side. You saw a big splash in the ocean and then the feed cut to black. It looks like it just broke in half or blew up or whatever, and you still have those Merlin engines there. It'll be interesting to see what SpaceX does with this. Or if Jared Isaacman, billionaire Polaris Dawn commander, who flew on this booster, buys it and mounts it. I don't know where you would mount that. Oh no, I think.

0:06:44 - Rod Pyle
Steve jervison will buy it. Yeah, he'll make an office chair out of it or something. You know what's weird. Excuse me for jumping in. Yeah, one of the press accounts I read it was from one of the more reputable outlets, I think so notspace.com. Hey, oh well, it wasn't you guys, I don't think. Quoted spacex is saying we'll evaluate it for possible reuse. So I don't know if that was before they saw what was actually on the barge, or it.

0:07:10 - Tariq Malik
It could be. Those are, those are beefy, uh, rocket engines. There could be something that they might be able to requalify after it, but they're going to look at it to see, like what happened for sure, and you know we're we've been talking a lot about, oh, this is so aty. I think it's their first failed landing since 2013,. Something like that. A long, long time it's been since they missed a landing 260 something successful landings.

Exactly, and the one wrinkle is that the FAA announced shortly after the failure that they want to investigate it, I guess to make sure that there wasn't any issue with the booster itself from launch that could have caused it, which would have affected all other SpaceX missions. But SpaceX stood down from a second Starlink on the same day and their Polaris Dawn mission, which we're going to talk about in a bit, also has been pending.

0:08:02 - Rod Pyle
And let's make that not a bit. Let's make that now. Also has been pending, and let's make that not a bit. Let's make that now. Polaris.

0:08:07 - Tariq Malik
Dawn Delayed again, darn it. Delayed again by weather, apparently this time. So this is the mission we were alluding to earlier. Billionaire Jared Isaacman bought another trip to space with SpaceX. Actually this is the first of three trips under the Polaris program, polaris Dawn, to attempt the first ever private spacewalk fly higher, the highest mission since Apollo 17, actually in 1972, and then hopefully just break a bunch of records across the board.

They were delayed by helium links on the ground, then again by more rocket checks and then by weather at the splashdown site five days after launch. They want the forecasts are really bad apparently for that. They want those waves to be low so they can go recover the crew easily. And after they delayed the launch from I think it was the 28th they were looking for, they're just pending. They don't know when the weather is going to look good for landing now it's really strange that they haven't said that it's delayed because the FAA has kind of grounded SpaceX's launches from that booster failure from the landing. But we'll have to see if if that has any kind of impact on that. Both SpaceX and Jared Isaacman have said it's really just the weather that they're still in quarantine, this private crew, and they're hoping to fly as soon as they get word.

0:09:32 - Rod Pyle
All right, and let's wrap this up with, we have some additional information on the failure of Astrobotics. Peregrine Landers no Intuitive Machines Peregrine Landers right.

0:09:42 - Tariq Malik
No, no, no, it was Astrob. Astrobotics, yeah, yeah yeah, astrobotic, they had a press conference.

0:09:47 - Rod Pyle
If I say it enough times, I'll get it right.

0:09:49 - Tariq Malik
They had a press conference this week to talk about what exactly failed on the Peregrine Moonlander when they launched it. On what? January 8th this year, which was the first flight of the United Launch Alliance's Vulcan rocket year, which was the first flight of the United Launch Alliance's Vulcan rocket, and, as our listeners might remember, they never actually were able to reach it to the moon with the lander. It had a failure after separating from the rocket and the engines had problems and they were never able to make the orbit to reach the moon and instead it came back to Earth. I think it re-entered the atmosphere on the 18th and burned up. You know, rip Peregrine Lander.

And so what they said this week is that they've pinned it down to what sounds like more leaks on a private vehicle and a faulty valve that wasn't sealed properly and because of that it kind of messed up the engine itself. They weren't able to use it properly. You can't use your engine properly and because of that it kind of messed up the engine itself. They weren't able to use it properly. You can't use your engine properly. You can't maintain your orbit, you can't do your orbit changes to leave Earth orbit, and that's what kind of spoiled the entire thing. It is a bit disappointing because as they were getting ready for their next mission NASA's Viper rover NASA canceled that mission too. So they're kind of in a bit of a quandary to try to figure out what the next steps are gonna be. But at least they know. You know at least as conclusively as they can what went wrong with Peregrine, how to make the next one a bit better and maybe offer some consolation rides to the customers who lost their trip to the moon.

0:11:24 - Rod Pyle
Very good, all right. Well, we're all caught up. Thank you for that, my friend, and we will be back after this short break with Dr Rosalba Perna. Stand by and we are back with Dr Rosalba Perna. Thank you for joining us today, Rosalba. We really appreciate it.

0:11:39 - Rosalba Perna
Thank you for inviting.

0:11:41 - Rod Pyle
So you are a professor of physics and astronomy at Stony Brook University, which always impresses me.

I was in astronomy, actually, I think both Tariq and I were trying to be astronomers at one point in our lives, desperately, desperately trying, and when we discovered how much math there was, we decided to be journalists instead. So my hat's off to you, especially as an astrophysicist. I have a question about your teaching, if I may. This is kind of an aside, but I took every astronomy class possible at UCLA and a college I went to before that, and at least in the first couple of introductory classes, the dropout rate was about 60%, which might have had something to do with the professor we had. He was kind of tough, but I found later, talking to them, that about half those people that dropped out had thought they were going into a class on astrology and when they discovered it was science, they were like well, this isn't what I wanted to study. Has that ever happened to you?

0:12:38 - Rosalba Perna
It's actually very funny because one of the classes that I teach and some are this 100 level there are sometimes students that come with the idea that there is absolutely no math, meaning no algebra, and those are just algebra. That is there, but also, yeah, that maybe it's more about constellation. So I actually have a slide in the intraday that said, well, this class is not and I put it's not astrology.

0:13:07 - Rod Pyle
So you let them know early enough that they can drop out and get your money back. And I just want to read this brief bit because it was so impressive and I hope I pronounce all the words correctly. Your research interests include theoretical astrophysics, magnetohydrodynamics and turbulence in the atmospheres of hot Jupiters, dynamical effects from stellar encounters on planetary systems and, I think, another paragraph or so of material. Did I get that right?

0:13:36 - Rosalba Perna
I like to work on different things.

0:13:41 - Rod Pyle
Very modest of you. So we are here today specifically because I saw a paper you did an article on it about rogue planets, which of course, is a great title, because it sounds frightening, these planets that have detached or been created outside of star systems as we traditionally understand them and are hurtling through space, dark and scary and who knows where they're going to show up, and ooh, what if one comes to our solar system and all that.

so those are a number of suppositions you're going to have a chance to correct over and over again but I think, before we get into what they are and how they form, the question that'll be at the front of every mind, everybody's mind, is could one of these come close enough to our solar system to create a disturbance sufficient to? That's what we all wonder about well before that.

0:14:33 - Tariq Malik
Before that, can we ask how she got into space though, rod? Yeah, just, I'm very interested in everyone's path to space and so you know, is it something that you were a bit like as a youth, or as it's an interesting question because I kind of never remember the time I decided I wanted to do astrophysics.

0:14:54 - Rosalba Perna
Because I feel like I always knew, when I was five years old, that my parents remember that I was just started to read and write and I said that I liked the universe, I wanted to be a scientist, and that never changed. So I never had the moment where I say, okay, what am I doing in the future? Or an inspirational, sometimes a spiritual teacher. I don't know where it came from because neither of my parents is a scientist. They were elementary school teachers, so they were puzzled themselves about me wanting to be a scientist already five years old. So I feel lucky that I it was. You know I get to do for work. You know what it was always my passion.

0:15:37 - Tariq Malik
That's what I always tell my daughter find what you love and find a way to get money for it.

0:15:40 - Rosalba Perna
Make it, make it, make it.

0:15:43 - Rod Pyle
It's the best, it's the best yes, so did you know kind of what direction you wanted to take once you got into undergraduate school?

0:15:50 - Rosalba Perna
So, yeah, undergrad. Yeah, so it was like physics, so that was undergrad. So, yeah, it, never again. There was not a thought of what am I doing. It was like, okay, I'm doing physics and then specialize in astrophysics. So it was yeah, new forever.

0:16:04 - Rod Pyle
Okay. So, Tariq, are you satisfied now? Yeah, yeah, I'm sorry, I don't mean to interrupt I just.

0:16:09 - Tariq Malik
I like the path as a whole?

0:16:11 - Rod Pyle
Are rogue planets a threat to us Right?

0:16:16 - Rosalba Perna
So it's so. Yeah, so the interesting, so this rogue planets are just to put in context for everyone, are are worlds and they are untouched to any stars, so they're free-floating in space. And one of the questions is that if one were to approach our system, what would happen? So there is two answers to that. One that the likelihood that one of these would approach us are probably rather low. So it wouldn't.

Yeah, so that's the first thing, but it's also there is an old spectrum of as we got into it, most likely of rogue planets in terms of massive sun, which are more Earth-like, other than more Jupiter-like, but the ones that, from recent surveys, seem to be more abundant are the ones, the tiny ones. So then, if a tiny one were to come close by, it wouldn't be as dramatic like if, instead, it was more like a Jupiter one. But the probability that the free-floating Jupiter approaches our Solar System right now they're not very high. So we are not in a super dense environment, unlike other system star forming regions which are very, very dense and where there's a lot of chaotic interactions and flybys which can eject planets and disrupt planetary systems well, I think I think that's my next question there, rosalba is is what exactly is a rogue planet like?

0:17:48 - Tariq Malik
is is it one that is a rogue planet Like? Is it one that gets kicked out of its solar system? Is it one that forms in the vastness of space, all by itself, in the dark, which sounds really sad, but also like an average Saturday for me, sadly. So what, to you as a scientist, do you classify as a rogue planet? Because it sounds like there isn't like a size.

0:18:11 - Rosalba Perna
Right. Well, so there is in terms of so, as far as like observation. So these planets were not theoretically predicted, so they started to be discovered and now we're trying to, you know, make sense. So, going to the question of where they're coming from, which I'll get next, so this rock planet again. So there are isolated objects that we see and we have seen in both the Jupiter-like ones as well as the small Earth-like ones.

So where we are is, first of all, where we classify in terms of masses. As far as planets, it's usually below 13 Jupiter masses. Above that, so between 13 and roughly 75 or 80 solar masses, we are in the regime of brown dwarfs. Brown dwarfs are, in other words, they're failed stars. They're objects that started the process of formation very similar to stars, that is, by collapsing as a cloud. And while stars are able to collapse to a level at which that center region becomes hot enough to ignite fusion, in the case of brown dwarfs that doesn't happen. The fusion of hydrogen to helium doesn't happen. So that requires a minimum mass which is on the order of 80 Jupiter masses. So above that we can form a star. Below that there are objects which we call brown dwarfs, which again cannot ignite hydrogen into helium, but they can ignite deuterium and that goes all the way down to about 13 Jupiter masses. So this is the brown dwarf range. So we call planets sorry, going to the question. So it's a more astronomical definition. It's something below, basically, 13 Jupiter masses. Those were planets in terms of mass. Therefore, there is a continuum as far as what we see in terms of this rogue world.

There are a lot of brown dwarfs out there, isolated. Now, what forms them? That's a big question that astronomers have been asked and there are various mechanisms that have been proposed over time. So something that can happen. So when the solar system assuming that planets form in a solar system, as we believe in standard theory, our understanding of the sun and these planets, we transpose it out there. But something that we know, and we know also from our solar system, that the early phases are very chaotic. Now the solar system is relatively tight, with planets going into quiet in their orbits.

We have a bunch of small objects that are, however, very confined in belts. They are there, but once upon a time, when the system was formed, there was a lot more chaos and motion. There were many more of these asteroids and smaller debris. They were floating around and kicking and we see some remnants of that in our solar system as a matter of fact, like the axis of Uranus, for example, is tilted, and if we look at the surface of planets like Mercury, it has a lot of craters. So those are craters of bombardments from the past. So we know that there was a lot of chaos. And in all of that, also planet-to-planet dynamical interaction become important. And if you have a giant planet like Jupiter, one approaching a smaller one, in this process of interacting all further smaller ones are being kicked out. That's one mechanism, it's the most straightforward one, so to speak. It's something that theorists have been able to reproduce with numerical simulations. So they simulate, start forming systems and they see that in this dynamical interaction there are some ejection, preferentially of smaller planets.

0:22:19 - Rod Pyle
Well, speaking of fusing hydrogen and making things burn, I have a burning question that I'm going to ask as soon as we take this break. Wasn't that clever? We'll be right back, so don't go anywhere. So I read in one or more of the articles that the Webb Space Telescope has been a real gift to searching for these things, and I guess I think it was a Webb discovery. Was that a lot of them are binary systems? Yeah, Raises a whole bunch of questions. If these things are booted out of existing solar systems as part of planetary formation and the revolution, why in pairs? Does anybody know?

0:22:57 - Rosalba Perna
Right, so that's a big question. So it was again. It was a very unexpected discovery of the GIS web and something I should say as a start. So there's so-called candidates. They were observed in the Orion Nebula. So they observed about 500 of free-floating single planets and among those 40 were-.

0:23:23 - Rod Pyle
That was in the Orion Nebula, you said.

0:23:25 - Rosalba Perna
That was in the Orion Nebula, the Tropidium Cluster, which is a particularly dense region within the Orion Nebula. So they are still in the process of being confirmed, because they were observed photometrically, so they see the color, but there can be degeneracies, so dim colors could be a planet, but it could also be a star, which is partly obscured, and so forth. So that's something to keep in mind because, as astronomers, we're waiting for confirmation, because, whether they're all of them or if it's a fraction of them, that carries quite a bit of implication for theoretical models. So because theory, from a theoretical point of view, there was no, you know no prediction of any of this, and so, given the observations or this, you know, candidate observations, theorists have been obviously very interested, like myself, in trying to figure out the mechanism by which they could be formed, and so there are a number of ideas, and one I worked on with my former grad student, ian Wang, who is now a postdoc at University of Nevada, was related to the fact that the planets are formed in a normal solar system, so to speak, so that we know the one thing is that they have to be in relatively outer orbits, which we see a fraction of planets at orbits of several hundred AU.

Au is the distance between the Earth and the Sun, so many hundreds of times the distance from the Sun for this planet. So they have to already be outside. But then as a star passes by, which happens relatively high frequency, the denser a cluster is. Then there could be ejection. So the star is basically giving a kick during the process and in this dynamic interaction. Well, very often single planets are ejected. But every so often, if the orbits of the two planets or the two outer planets are relatively close by at the moment of the interaction, the interjection can happen and lead to a binary. So that's one mechanism that was proposed a posteriori for, uh, you know, try to explain it. Um, I was gonna.

0:26:03 - Tariq Malik
I was gonna say can you really be a rogue planet? If you're a binary, though, because, like, rogue planets to me are like Batman they only work alone, and if you've got a binary, then you've got a friend.

0:26:15 - Rosalba Perna
Yeah a friend, right? So you're not rogue at all. Yeah, so I guess it's a free flow thing, right?

0:26:22 - Tariq Malik
But I had a kind of a related question, Bazalba, because Way to bring it to the masses, brother, right, I'm just saying I'm just saying right, because we talk a lot about these rogue worlds. But I'm wondering, like what if one of these planets has like its own moon or like a whole bunch of moons like Saturn or Jupiter. Do those get ejected with it?

0:26:45 - Rosalba Perna
Yeah, it's an excellent question indeed, because some also I was sorry starting with one more that I work on, but then again there can be other. So other mechanisms, which is exactly as you're saying. So if you have two, I mean assuming that the two you know, normally the moons tend to be smaller than the planets. But you know, one could imagine a system where you have a planet and then its own moon is relatively sizable compared to the mass of the planet, and then when you have an ejector it will work almost like a single ejector and you eject it at the same time. So it's a similar mechanism, except that they are already in a binary within the solar system. So that's one other possible mechanism that could work. And then there is the possibility that they were formed in situ, like stars and brown dwarf, but that's one that in principle one can make as many as one wants. In practice there are theoretical difficulties with that. So even for forming single planets below a certain mass, which is believed to be around three Jupiter masses, clouds, as they collapse they become unable to cool. So there is a condition called opacity limit, which basically they can't get rid of their heat fast enough and therefore they stop collapsing, and that happens around three Jupiter masses. So it's believed that unless there are unusual circumstances, like you have a supernova exploding nearby and therefore you have an extra punch to make it compress, they would not naturally form in situ. And then even more so, imagine it's hard to form one, imagine two as a binary. So mechanism by which, as the one you suggested or others, which is the one you suggested, where planets were formed as we believe in a planetary system, and then they went into other space as a binary, those are possibilities Again, unless in situ one finds ways to bypass astrophysical limits that don't suggest that deformation to be natural.

There is also another set of observations that astronomers have noticed. Usually stars come in pairs In situ. Massive stars, actually the abundance is very high. Stars, actually the abundance it's very high, it's more than 50%. But then what astronomers observe is that as one goes lower and lower in mass, the binarity fraction becomes lower and lower and lower. So brown dwarfs, for example, have much, much low binary fraction. So it seems a bit unnatural Again, it's not impossible but it's unnatural that you have a trend over order, magnitude and scale in binarity. Then that turns around when you go to the very low mass where it's actually, there is a reverse and the binary starts increasing with decreasing mass. So that has been another puzzle, and one that would have to be explained if these observations are confirmed.

0:30:15 - Rod Pyle
All right, I do have a question, but we have to go to another break, so stay with us, we'll be right back. So this question comes from a friend of the show, isaac Arthur, who has a very popular YouTube channel called Science Futur with Isaac Arthur, and we love Isaac. So he asked me to ask if you have a larger rogue planet, say a gas giant, like some of them appear to be. If it had moons, could they be affected by tidal forces like we see with moons like Enceladus in Europa and our own solar system, and possibly have warm oceans underneath?

0:30:51 - Rosalba Perna
Yeah, I mean absolutely. So that's, you know, tidal effects work everywhere. You know either these giant planets are attached, you know they are within a solar system, or if they are isolated. So yeah, so that would be very interesting. It's only, what matters is the distance. So, because tidal effects are a function like the gravitational forces, it depends on the distance and the composition to a certain extent. So the more compressible the material of the moon, the easier it is to be subject to tidal effects at the same distance.

0:31:32 - Rod Pyle
But yeah, it could be like a rope if we were to find so would an icy crust be more compressible than a rocky crust, for instance?

0:31:40 - Rosalba Perna
Right, you're right. Yeah, icy, it's more compressible than rocks, indeed, or a sponge cake. Sorry, go ahead that would be an interesting moon more impressible than rocks indeed.

0:31:48 - Rod Pyle
Or a sponge cake or a sponge cake.

0:31:49 - Rosalba Perna
Sorry go ahead.

0:31:49 - Rosalba Perna
That would be an interesting moon.

0:31:53 - Tariq Malik
I had seen a lot of talk a few years ago, Rosalba, about the role that dark matter might play in rogue planets. Just because we can't see it, we want to know where it is. Maybe, it's hiding in these rogue planets. Is that still a viable theory that, like there is, there are dark? That's where all the dark matter is hiding in these planets. We haven't been able to detect as much.

0:32:16 - Rosalba Perna
So that's a very good question indeed, because it's so, the, in a way, the discovery of the some of these rogue planets, that happen via microlensingensing. So some have been discovered, as we we were saying before, with uh, direct imaging, with the james webb, but actually in all other sets, the, especially the smaller, dimmer ones, have been detected via gravity, via microlensing. So microlensing, just uh, as a refresher it's, it's a phenomenon by which it's a result of the theory of general relativity, by which light is deflected by a massive object and it results in double images and an amplification. Now, when the planet, when the object that's doing the lens, is small, we don't see the effect of the double images, but we do see the amplification.

So, astronomers looking for potential dark matter candidates, which indeed could there be any sort of like black holes, for example, that were a candidate with free floating in space, or again, brown dwarfs, which after a while cool completely, the only way to see them is via their gravitational effects. So there have been searches to this effect and well, the result is that they would make up only, I believe, from well, I remember from the latest survey up to a percent. So unfortunately, dark matter still remains a mystery. But in the process we have actually discovered a number of these rogue planets, so they cannot make a dark matter, but it was an interesting, definitely an interesting possibility, at least for brown dwarfs. They're also more massive, so they could make more, um, so yeah, so the two searches that way.

0:34:15 - Rosalba Perna
sorry guys, no, go ahead good, no, I was saying it, yeah okay, you guys, come on, take a turn quick yeah, so, so, let me, let me, let me.

0:34:24 - Tariq Malik
I I have um. Is this a good time for my list of questions, rod? I have a lot of like they're kind of silly questions we count on you for those there's no silly questions.

0:34:34 - Rosalba Perna
Oh yes, there is. You don't know time very well you haven't seen these questions yet.

0:34:39 - Rod Pyle
Okay, we call him Dr Clickbait, sorry.

0:34:42 - Tariq Malik
I was thinking about rogue planets. You know we talk about the science, a lot of which you know there's much. But I'm just wondering, I mean, as a human on Earth, you know, could we live on a rogue planet? So you know, we find one of these things out there. Could we go set up a colony or something on it?

0:35:16 - Rosalba Perna
So it would be. Since they are, by definition, a big rogue planet, very far they're not attached to any star. We would have to have our own way to produce energy, because we rely on the sun for light and for energy. So we would have to be super smart in order to be able to live without a source of light. So having our own way to so that will be a big, you know it's a big difficulty.

0:35:34 - Tariq Malik
A challenge.

0:35:35 - Rosalba Perna
It's a challenge, right.

0:35:36 - Tariq Malik
It's not like going outside in Los Angeles at night where you have like all the light pollution everywhere, where there's just ambient stuff there. If we could Don't be beating up on my city, my friend, I lived there for six years. My friend, if we could live on one, I'm wondering what would you call yours? I think Tarktopia sounds really nice, but if we could live on one, what?

0:35:58 - Rosalba Perna
would you call it? That's an interesting. What would I call it? My pre-floating planet. I hope for something lyrically italian, maybe like tosca or something essentially the last time I saw it, so it was coming to my mind as a matter of fact.

0:36:21 - Rod Pyle
Okay, so, okay so tarik, now I'm going to jump in, so because you you brought up a good question and then I'll let you get back to your list. If this rogue planet was a brown dwarf and the moon was close enough, might that, you know, say we had tidal flexing and some thermal energy coming from the brown dwarf? Might that be enough to support life on the moon?

0:36:43 - Rosalba Perna
Right, so it again. It would depend because a brown dwarf, it's something that's hot for a period of time, but then it cools off very quickly because it doesn't have a real long-term source of energy, unlike the sun. So we may have, by putting ourselves at the right distance for a period of time, we might have the right conditions, but they would not be as long lived as for the sun, which lasts billions of years, so-.

0:37:11 - Rod Pyle
So, Tariq, what she's saying is, life would have enough time to evolve to where you and I are, not to where she is intellectually.

0:37:23 - Tariq Malik
That's awesome.

0:37:24 - Rod Pyle
Oh, hey, look what I found. How about that? It's my mouse pad. Okay, I'm sorry. Go ahead For the audio listeners. I was holding up a CD of Turandot. Go ahead, tara.

0:37:36 - Tariq Malik
Yeah, so this is something that some listeners might be wondering about. But I'm curious could Earth ever become a rogue planet, you know, in the far future, or if we get a black hole that wanders by us, that kind of thing?

0:37:50 - Rosalba Perna
So the Earth is absolutely so for the Earth.

So the Earth is with the Sun, which is, it's a low mass star, our Sun. So, in general, if a planet is around a more massive star, so above seven or eight solar masses, then the star will end its life as a supernova. Now, when a supernova goes off, it releases a very giant amount of energy, very sadly, and with that the planets that were in orbit around the star can be easily ejected. Now, in the case of our Sun, it will evolve into a white dwarf. So it's a slower process, but the Earth at some point will get very hot, but there won't be an explosive event. However, if a star were to pass nearby, the Earth could be ejected, or even if it wasn't, you know, maybe happened directly with the, you know, with it as a direct ejection, but it could, for example, if it makes the orbit of Jupiter be more stable and then sets a series of dynamic instability within the solar system. And if that happens, the planets that would suffer the most and be most likely ejected would be the lighter ones.

0:39:13 - Tariq Malik
Man, jupiter, just wrecks everything.

0:39:17 - Rosalba Perna
Jupiter is actually responsible. We think of it just as a giant ball of gas, but it's actually responsible for quite a few things in the solar system, including, well, some good things, for example, because there were a lot of objects moving around and Jupiter sort of moved them in a belt, which is now protective for us because we don't receive as many giant asteroid impacts as in the past. So that's a good thing.

0:39:47 - Tariq Malik
And I think I have time for one last silly one, and this is just about rogue planets. In like sci-fi history, I'm curious if science fiction gets rogue planets right, like when worlds collide the classic one. But I also I always wonder if, like Endor, that moon of Endor is like orbiting a rogue planet in Star Wars. Do you have a favorite sci fi rogue planet to pick from, or or is it just not as interesting as the real thing?

0:40:15 - Rosalba Perna
I've been following more of the real thing, I confess.

0:40:21 - Tariq Malik
There is an episode of Star Trek Enterprise where they land on a rogue planet.

0:40:24 - Rosalba Perna
Okay, now I need to.

0:40:25 - Rod Pyle
Tariq, while you were sitting in theater watching star wars for the 42nd time, she was doing her second postdoc.

0:40:32 - Tariq Malik
Okay it could be why we didn't get our astronomy degrees right oh, I think there's a lot of reasons for that.

0:40:38 - Rod Pyle
I'm sorry, did. Did we let you answer the question? Was alba or did you have anything on that?

okay all right, let's, let's go to our last break and then we'll be back with my not dumb question Stand back. So this is kind of a two for one. Part of it's, I think, research that you may or may not have participated in, and then something you definitely did. So I read one bit about the Webb telescope being pointed at the Orion Nebula for just 35 hours and the data from that amount of observation spotted if I get this right 42 pairs, so 84 rogue planets, and ultimately, I think, as you mentioned, spotted 500 of them. So that I thought was pretty amazing. But then you worked with a couple of other researchers to create a digital model to test some of your ideas, and I think it involved flying simulated star masses past simulated solar systems with Jupiter-sized planets and discovered that it's not difficult to find conditions where two giant planets could depart as a pair, and then I guess they stay in a binary orbit around each other as they're slinging through dark space, right?

0:41:51 - Rosalba Perna
Right, so it's. So it's a. You summarized that very well. So we did embody simulations, so computer simulations, where we started with the system of a star and two planets, two Jupiter-like planets in other orbits, and then had a close flyby of other stars happening and see what happened. And in the process there are many single planets that are ejected, but also binary with a fracture on them. So we did find that some binary planets can be formed through this process. It does require a specific initial condition for the planets for the solar system, so they have to be already in outer orbits because, if you want to reproduce the observations of a GEMSweb, these binaries were relatively large separations. So they are ready and the separation in which they are ejected reflect the separation in which they were in the initial system.

But something I should add is that the initial paper was more focusing on the creation mechanism.

However, we followed up more recently with another work which goes back to your second question relates to the second question, which is then they have to remain as such in the outer space and something that we see is that for a binary system, a binary made of two planets, it's actually it's hard to keep themselves as they are.

So it requires um, because the other interactions you know the russian keep happening. So if they, there was a certain likelihood of a star flying by for the original uh solar systems. There will be also other stars flying by for the binary planet, so many of them will end up being disrupted over time, or the semi-major axis will change and so forth. So it's actually like reproducing all 40, if they are confirmed to be, because again we still don't know, as Jupiter mass planet is actually non-trivial from a theoretical point of view. So the mechanism it would require a very high production mechanism because, as again we found more recently in this work, they get disrupted also at a very relatively high rate. So we're very much looking forward to the spectroscopic confirmation of this object. I guess right now you know they could still be, you know, misinterpreted as distant stars, or some could be burned worse, and so forth.

0:44:41 - Tariq Malik
You bring up a really great point, because that was right into my next question. You know, Rod, and you've been talking about all these different rogue planet candidates that have been found with James Webb and I'm very curious about what the biggest challenge is to finding them, because a lot of the methods that I'm familiar with that we've used just to find regular exoplanets is like we look for its effects on the parent star. Right, Does it make a problem?

0:45:07 - Rosalba Perna
Does it pass in?

0:45:08 - Tariq Malik
front and. I'm wondering what do you see as the biggest challenge to finding these things? And then, how does something new like James Webb kind of change that challenge or make it a little bit easier, right?

0:45:23 - Rosalba Perna
So the James Webb, so one thing that allows, will allow, indeed, to you know, be absolutely sure that these are planets and not other objects, not, you know, distant stars or brown dwarfs is taking their spectra, and James Webb can actually do that. So detailed imaging of the objects, looking at their spectra. So if they're Jupiter-like, there will be trace of methane, other compounds that we know, water and other that we know they're part of the atmosphere. So these giants, so it requires spectra and that's something for which James Webb has the capabilities to do. So that will be on the front of this giant. On the other front of discovering planets via microlensing, there will be the another new world of discovery in a few years, when it's being launched.

0:46:28 - Tariq Malik
Yeah, that's the Nancy Grace Roman telescope that NASA wants to launch in October 26, 2026, I think 26 or 27, yeah, something like that.

0:46:37 - Rosalba Perna
Soon enough for astronomy class.

0:46:39 - Rod Pyle
Keep our fingers crossed and hope it doesn't get canceled along with so many other things. Tariq, you got more.

0:46:46 - Tariq Malik
Well, I mean, I think just the last question that I would have is just about other research. Like what are the pesky questions that, rosalba, if you had a magic wand that you would be able to answer about these exoplanets? Like I always wonder how close to the planets we see in our solar system that they could be like, but then if they're wandering around without a star, it just seems like they'd all be just really frozen ice balls. So I'm just curious what other research, what keeps you up at night about these objects out there in the void?

0:47:19 - Rosalba Perna
Yeah, well, I'm very interested in how they formed. So how did they get there? And because that relates also how planetary systems formed and the interior planet formation are still very much in development. We thought with the solar system that we had kind of the very basics and we understood. For example, related to these mysteries. We knew that Jupiter-like planets have to be formed outside a certain distance, which is called the frost line, where volatiles can be in condensed form. We knew that and perfect that Jupiter and all the others are outside. But then actually the very first planet that was discovered in 1995, had Jupiter very close to the stars Already. As we observe other systems, we see that the theory as we had it it's largely incomplete. What keeps me up at night is thinking of more of the physics that goes on for a fuller understanding of planet information on a larger scale, so beyond our solar system, our home.

0:48:29 - Rod Pyle
So see, Tariq, that's one of the reasons you and I didn't become astronomers. She doesn't lie in bed at night worrying about her next session of whatever the hell that video game is. You play on Twitch all the time. So, rosalba, I guess for my last question, I was looking over your website at Stony Brook and your list of research interests is longer than the last Costco receipt that I got which is pretty long. Can you talk a little bit about some of the other things you're interested in and what you're working on?

0:49:04 - Rosalba Perna
Yeah, so my formation, so to speak, my PhD thesis, was in gamma-reversed, which are explosive events associated with the collapse of massive stars on one side and another. There are two sets, the longer ones and the shorter ones with the merger to neutral stars. So I've always been fascinated by compact objects where gravity is extreme, and you know neutron, neutron stars of black holes, and now that we have observed the gravitational waves, I'm also very interested in the counterparts to gravitational waves that are produced when two neutral stars merge. That's an all area of research, more recently also in active galactic nuclei, which are very bright sources that we see in the distant universe, and in objects in their disks, so neutron stars and black holes that are harboring there. So that's the opposite of rogue walls. We knew most of the neutron star obliquals wandering space, and here it's actually neutron star obliquals in a very defined location, which are the disks of these AGNs, which then gives rise to all set of other interesting phenomena that I've been very curious to study recently.

0:50:24 - Rod Pyle
Sounds like you have a real like for dangerous things. Maybe yes, I think so All these things sound like they could be really bad for us. Well, I want to yes, a camera burst that could be, I say, yeah, well, just make sure you're not on that side of the planet when it happens, right? So I want to thank everybody. You, you spent another hour with us for episode 126 of this week in space on rogue planets, Rosalba. Where's the best place for us to keep up with your ongoing research efforts online?

0:50:51 - Rosalba Perna
thank you for um, uh well, I usually about all publications are uh well, they are online. So you know, google scholar ideas is the standard thing, and then sometimes, when things are being picked up by the press, they're written also in more friendly way, Darrell Bock.

0:51:12 - Rod Pyle
Yeah, okay, that I do understand Well, so probably the best thing would be to set a Google alert just using your name, and that way you'll find the stuff that Tariq and I can understand. Speaking of Tariq, where can we find you battling the forces of first world water pressure these days?

0:51:28 - Tariq Malik
Well, since school's about to start, maybe I'm going to go try and crash and audit one of Rosalba's classes in Stony Brook. So if you see me, just kind of look away, because I'm just trying to learn new things.

0:51:39 - Rosalba Perna
But so if you see me, just kind of look away because I'm just trying to learn new things.

0:51:41 - Tariq Malik
But now you can find me on space.com, of course, as always on the Twitters at Tariq J Malik, Maybe on YouTube @SpaceTronPlays, where I'm going to try to play some games. New Star Wars game out this week actually. That could be a lot of fun Star Wars Outlaws but we'll see. We'll see, because the Fallout 76 season starts next week and I'm nowhere near done with the current one, so we're going to cram for Labor Day weekend.

0:52:08 - Rod Pyle
Just so you know, if Tark does show up to audit your class, you'll be able to spot him, because he'll fall out of his chair at some point while you're teaching. Oh my gosh, sorry, that's a little bit of a side joke. Sorry, that's a little bit of a side joke. And of course, you can find me at pilebooks.com or at adastramagazine.com, and a lot of my work is on the National Space Society website, and both that and space.com are good places to find all the best space stuff. Do remember you can drop us a line at twis@twit.tv. That's T-W-I-S@twit.tv. We love your comment suggestions and space jokes. Send your space joke. I know that people look adoringly at the sharp edge of their kitchen knife when they hear some of my jokes. But save your jacketers. Send us a space joke so we don't have to read mine, although this week's was pretty good, uh, new episodes, this podcast published every Friday on your favorite podcatcher.

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