THE EDGE OF THE SOLAR SYSTEM | Dr. Konstantin Batygin | All Space Considered

so we are happy to welcome our speaker tonight and Constantine we don't know you that well so we thought we'd go the conservative on this was actually our first idea to welcome to our stage dr. konstantin batygin it's always scary to do that to a guest that you don't know but you know what's weird is I actually have exactly the same picture that I made myself great minds so as I mentioned we've got these rings of many many many many particles on the outer solar system not as dense as Saturn's rings but nonetheless the same idea and they tell us a lot about our solar system so as I said this was something we took from your website can you tell us what we're looking at there absolutely so these are beautiful ellipses these are actually the most distant orbits of the solar system that we know of so what we have just to give you a bit of scale if you if you look at that purple purple ellipse that purple ellipse at its farthest point from the Sun which is that bright star right in the center it's a thousand times as far away as the earth is so that's that's kind of the scale of what we know at the moment now allow your eyes to kind of ignore the the cyan thin thin lines here these guys are somewhat separate story if you just look at the ellipses that look like they're in the plane of the screen right here right you will notice that they're all kind of corralled it all looks like they're they're all pointing in the same direction right I'm not the only person who sees this yes that's actually a remarkable remarkable dynamical feature of the distant solar system if you zoom in somewhat and check the remainder of the Kuiper belt this will not be the case it's only the most distant orbits that are all pointing in the same not that confinement that clustering of orbits is actually what's giving us a hint a gravitational signature if you will of the existence of Planet nine and not that stupid Pluto actual planet nine which is whose orbit is seen here as the orange ellipse and actually I should say Pluto is a wonderful little world right I mean like I'm I when the New Horizons pictures from 2015 came back I mean I was just genuinely amazed by them you know especially the parts the geology of Pluto is so so much more rich than what anybody could have expected the kind of on the plains you see kind of the cracks and ice where the convection cells are coming up I mean it's just the coolest thing but it's fun to you know okay so we've seen that picture of the sort of flat distribution we see this crazy distribution so that brings the question what actually is the Kuiper belt and I'll begin by saying it was it's named after a guy named Gerard Kuiper there he is we looked for a picture of him standing up so we could Photoshop a belt on him but you know what we couldn't find one so we just put all those around but anyway as we'll just leave it here and any visuals you want to show this is the last we have for you yeah but I wanted to ask you so so tell us about these different populations who are the ones that are the flat they have all kinds of crazy names like QB WOM and put the bootie nose and QP wonho's and what are all these different populations and what do they tell us when I say populations I just mean bunches of these things that have common characteristics but they're they're they're distinct indeed what do they tell us so really this sole the Kuiper belt is is exceedingly rich and the information that it tells us about how the solar system form the solar system we used to think about 30 years ago hadn't evolved right I mean generally when you think about space you kind of are tricked into thinking that it's immutable that things are just going around and it's all kind of happening slowly so you think that there's this constancy to the solar system that's not true the solar system formed in a state that is quite different from the architecture that we have today in particular the outer sole of the outer planets of the solar system Jupiter Saturn Uranus and Neptune all formed considerably closer to the Sun than they are today and after about 600 million years of staying in that state that's about 10% of the solar system's lifetime to date they underwent a transient period when they scattered one another they they went unstable and jumped so their orbits changed they expanded by about a factor of two during this instability which is these class of instability models is often referred to as the nice model all of the icy debris that was in that region got scattered out to beyond Neptune and that the remainder of that population is the Kuiper belt so what we see today if you will are the small pieces of the shipwreck that is that is the solar system and that those small pieces tell you a lot more about what happened the dramatic story of our solar system than the planets themselves because there are a lot more of them and you can study that their structure in much greater detail so these populations have different distributions and dynamics and motions and they talk about the different eras of the scattering absolutely in fact why don't we switch over yet to my laptop and I have a little video here of the solar system to scale so we have here Mercury Venus Earth my house about right there and there's Mars Jupiter Saturn Uranus and Neptune in a second we will see Pluto right so Pluto as you already mentioned is not exactly in the same plane of the solar system as are the remaining planets and we'll go to the plane of the solar system in a second you can see that sort of 25 degree tilt that indeed was the first hint that Pluto was actually popular part of a population that is different from the planets themselves and now what we see are all of the Kuiper belt objects for which we have really good orbits okay so this is the sizes of the dots are not to scale but the orbits that are shown there in orange are so from here you can you can tell that the Kuiper belt is not really a a ring in the same way as Saturn's rings are rings it's not flat Saturn's rings by the way are as tall as Griffith Observatory approximately that's how flat they are this the Kuiper belt is a giant doughnut and indeed if you study the populations they're kind of different sub structures within the Kuiper belt there's a there's a very rich story to be told but for today I think it would it would suffice to concentrate on two right one is the the this extended doughnut like collection of orbits and the other is this ring of material that is actually quite quite in the center in the plane so the that kind of lining of the doughnut so to speak is called the cold classical Kuiper belt and mu 69 is a member of the cold classical Kuiper belt the cold classical Kuiper belt we think is the only population of small bodies in the solar system that hasn't been disturbed right these are the only objects in the solar system that formed right there and they stayed right there the remainder of the Kuiper belt was emplaced where it is today by scattering off of Neptune and gravitationally that's why all of these orbits seem to physically hug the orbit of Neptune Neptune kicks them out and they evolve in this interesting way but they always come back more or less than where they started the orbits that don't hug the orbit of Neptune are the primordial members of the solar system so before we move on to some of the crazy outliers here working on let me just ask a couple quick questions about the cold classical's because of them emmy 69 first of all what do you think the results that we've seen so far tells us about the cold classical population no it's a great question yeah so one of the biggest problems of solar system formation for the last maybe four decades has been how do you form the building blocks right we see the castle that is the solar system but we don't understand the bricks why do we not understand the bricks the reason is if you try to form objects like mu 69 or asteroids or whatever by taking little you know rocks this big and convincing them to stick together it doesn't work in fact by the by that method you can at most build something that resembles a snowflake as it turns out if you take snowflake so anybody who's been on the East Coast knows this right these snowflakes do not come in you know 5 meter 5 meter rocks unless you're in Russia just things weird things can happen in Russia okay but right typically snowflakes reach about a centimeter and then if you take two centimeter snowflakes and gently allow them to collide they break apart so there's a there's a barrier to to growth and the new theory of plant information emerged in the last decade or so which suggests that rather than being built up piece by piece the way these objects form is that in the protoplanetary disk you snow basically snow forms these big clouds and through something called the streaming instability and once these clouds grow massive enough under their collective gravity they will collapse okay and they'll collapse and they will make these sort of 2200 kilometer bodies right now when that happens you you can't violate the laws of physics you have to conserve angular momentum so that process of collapse is subject to the same rules as a ballerina that jumps up and brings her arms in and spins up if you ever watch ice dancing or whatever when ballerinas jump up the they bring their arms in and they do a 560 or whatever okay so during that process what happens to these clowns well it turns out they can't there's too much rotation to just collapse them uniformly and turns out what they what happens they'll collapse into two boulders there will go into orbit around one another so what we see with mu 69 is a consequence of those two boulders that then probably Title II decayed upon one another and then just stuck now the Earth's moon due to tides on on earth or it's moving out Mars's moons one of Martha's moons is actually moving it so we see a consequence of that same physics in the distant solar system it's really it's really a fantastic result and they refer to the most planetesimals because they're the building blocks of planets like you were saying the the bricks so a totally important question is what's the composition if we're looking at these things that are the leftovers from our solar system formation but they're they haven't fallen into the inner solar system they haven't been toasted up by the Sun and lost their their gases or melted or reformed or any of that stuff they're as they were when the solar system formed so you heard me ask about composition to Alan because that is one of the huge questions what is that and how did the composition of the building blocks for the solar system turn into the planets we know and love especially this planet that we know and love so there's a through line from that little rock out there to those of us sitting in this room and planet-wide all the life on Earth because that's that's us when we were when we were babies okay with that negative 4.5 billion years old so let me turn then to the rest of the Kuiper belt because that's you know what we're seeing here in the classical what's the what's all that other junk and where to come from and you know where I'm going next after a and what I'm just suspect you know what I'm gonna ask you next about the crazy flying out ones why are they doing that yeah and that's a great question so look this this part of the Kuiper belt that you see up here this is the so-called classical region it's about 40 times as far away from the Sun as is the earth but now if you ask what are the most distant orbits that we know of today right they they swing out like that now this is a this is an object that my friend and colleague Mike Brown discovered back in 2003 he nicknamed it Sedna he discovered together with David my name is chad trujillo by the way chattri he was part of the same team that discovered far out oh what a guy no would you care to comment we aren't live streaming soon no he's a great guy he's a friend of mine yeah is he the one that came up with the name far out there I think it was Scott actually Scott Shepherd who's also on the on the team I think Scott comes up with the names because so their previous one was the Goblin which is which is also a pretty good name some people like it anyway so it's it's kind of a thing right one of the great joys of discovering a Kuiper belt object is you get to name it maybe so you know people come up with cool nicknames but here's the here's the neat thing about Sedna so if you look if you just look at this orbit it just it is staggering how elliptical and how how stretched out just how big it is right I mean that's the most astonishing thing about here's the really weird thing about Sentinel okay if you look over here actually it doesn't hug the orbit of Neptune right that's actually the most staggering thing about this object if it was just a really far-out ellipse okay all that that would mean it's just like this object we've been gravitationally scattered by Neptune and would have almost zero energy meaning it just like just barely attached to the solar system this object doesn't come anywhere close to Neptune so some other gravitational influence is required to explain its detached orbit and now for about a decade I mentioned that Sedna was discovered in 2003 for about a decade it was the only one and when you have one weird data point in the scientific field you tend to invoke a theory where you're like oh stuff like 4 billion years ago like stars or something right so that was kind of the explanation for about a decade but decade later Joe Biden was discovered orbiting the solar system in orbit like this ok Joe Biden's orbit is actually even more remarkable than sending them because even at closest approach the Sun it's a Tau away so once you have two data points you draw a line through them it's just like a big deal I just have to point out the VP in the name like M that's right that's right so again you know when you're up at the telescope it's like 14,000 feet there's no oxygen so you get in that real creative with stuff so really the discovery of of Joe Biden was the was the inspiration that led Mike and me to kind of look into this more closely and what we noted right away this was back in 2015 or so is that if you look at the most distant orbits that we know of not only some are some of them detached from Neptune they all seem to kind of number one lie and more or less the same plane right as you rotate it through you can almost put a piece of paper through this collection of orbits it's about 20 degrees inclined with respect to the rest of the solar system and as I already mentioned they're all pointing into the same direction and that's really weird why is it weird it's weird because if you leave the solar system alone for a geologically short time like a hundred million years this pattern would disperse quite rapidly right so the fact that they're they're all clustered together means that there's some gravitational influence that's that is close keeping them together so for the next 48 minutes I would like to you know it's a the only place where this yeah the only place where this slide did not get any laughs was I almost gave a talk at a math department they said all the rest of your slides are crap and this one is pretty good that's right yeah so so just to kind of close up the story you know it is no longer the 1800s so we're no longer limited to just doing math on the board and we have computers now in fact my office sits a couple floors above a supercomputer that was used to make this this simulation so what what we see here this is a simulation of the solar system's lifetime the distant solar system evolution over its four-and-a-half billion year lifetime where the orbit of Neptune okay 30 astronomical units 30 times the distance between the Earth and the Suns about this big all of these dancing ellipses are the kite the distant Kuiper belt objects that are simulated in in my in my code and what we have here is an additional body of the solar system massive object in the solar system so if you kind of watch this for a a while it looks like nothing interesting is happening the orbits are dancing around but if you watch it for a very long time you know a pattern begins to emerge and I think we're at about 1.9 billion years into the simulation now it is starting to be the case that the surviving objects of the distant solar system are all pointing the opposite way from the orbit of this of the actual ninth planet right there real-deal ninth planet see that's another that's a good name really the real deal right in the end it is simulations like these that tell us the story it's simulations like these that suggest that indeed the distant solar system is is hinting this structure that we see there now is pointing at the existence of a ninth planet and its orbit is very weird it's unlike anything else in the solar system it's orbital periods is about ten thousand years it's orbital inclination it's about twenty degrees it's 20 degrees inclined with respect to the rest of the disk and that's actually where that tilt of the observed orbits is coming from and finally its orbit is it's quite a bit more eccentric than the rest of the solar system so so we're very excited about it and this is a good maybe 30% chance maybe 40% chance that we'll find it within the next couple of months we have a whole bunch of data that we took in December at at Mauna Kea the Subaru telescope it's so much data that we haven't looked at it yet not because we're lazy well in part because we're lazy but also because it takes a really long time to process it and it is going to be this month is going to be a lot of work to to chug through this data and to understand what we found if anything so there are a lot of mysteries that that exist out there yet to find and in fact I think that the folks who found far out we're looking for planet 9 indeed yeah so the that group that team which primarily consists of Scott Shepard chattri here Dave full-on they are on the same quest as we are and you know we're we're friends were we're friendly we're also somewhat competitive well I think that they are a little bit maybe more competitive than we are maybe we're more competitive but it's yeah you know that that aspect of competition actually keeps the science fun right because we in the end you know when we are on the telescope we are kind of thinking okay you know like this is this is it like we've got a we've got to do this you know there's always the possibility of getting scooped and my friend Eric Pettigrew who's also an astronomer at UCLA is here and he you know we often connect over this this excitement of doing the science it really is a wonderful adventure well just to finish up a little bit on the picture of the outer solar system and with mu 69 in particular and New Horizons in particular one of the things that I mentioned earlier you couldn't really see because of the Sun angle whether or not there were a lot of craters but a first-look sort of suggests that there were not a lot of craters which is interesting because it's supposed to be filled with debris out there should be a certain impact rate and you there we have predictions very clear predictions about how many of how what size you should get so this is an exciting thing to try to understand the nature of the environment in which the the object exists because it hasn't come into the inner solar system it's being processed entirely by its environment out there but New Horizons will do more still to explore the environment out there and because it has been ever since it got to sort of just past Neptune and in the early front are the inner edge of the Kuiper belt has started measuring all of the fields and dust and a particle environment as it's traveling and and it's just gonna be like a line as it goes farther and farther from the Sun measuring the particle environment the dust environment and what they what the Kuiper belt is like out there and then can compare it to the surface of MU 69 and see if it all comes together in a consistent picture about what that outer edge of the solar system is now it's gonna be a long time before new horizon gets out to any of these more distant objects but it is still a very healthy spacecraft it still will be taking images and in fact because it's already out there then we'll have better resolution than Hubble does even though Hubble is a very high resolution telescope for some of those objects so it's going to look for them it's going to look for rotation curves that follow up on the ground here many looking for any peculiar variations in light or you know that that it will find and and I mentioned earlier they sort of ground truth proof of that occultation method allows further studies for every one of these objects that that New Horizons finds will be able to do those occultation studies and have sort of a zoomed in look at at the shape and see how many of them are these by lobed features which as Constantine was describing and I was describing a little earlier is what we think is the formation mechanism for that out there so there's a lot of I mean like I said we look at it we think oh oh it's not a cute little bowling pin with some smushed EE looking things on it but there's amazing science talks about in it and this is a somewhat unknown way everybody knows about you know my mother and pizza and whatever that thing's all like it's not pizza because my mother just did something with very nice am i talking nonsense my very excellent mother just served up nine pizzas yeah exactly so doesn't any disk and everybody learn that in school the one you learn but I just learned we still are a public institution so we'll save that for another day anyway the point is that it's not that there isn't you know it's not that Pluto's didn't been demoted it's that there's this whole third zone of which pluto is a wonderful member of MU 69 Sedna Makemake Biden we left Biden off our graph sorry about Huck and I don't don't tell Joe and we make plenty of jokes around Joe and this Joe so it's all right but anyway I know that we're gonna want you to come back and give us the skinny on this and especially you know the first place you're gonna come as soon as it's found right yeah after all we don't live stream when we can keep it a secret so please do remain up here we have only two very brief stories to tell before break but I would like to take this opportunity to thank our speaker again for just a wonderful [Applause] you you you

Channel: Griffith Observatory

Views: 11,076

Keywords: Griffith, Observatory, All Space Considered, Astronomy, Science, News, New research, Planet, astrophysics, live science program, Astronomy lecture, presentation, space, outer space, space exploration, NASA, Kuiper Belt, Ultima Thule, MU69, Konstantin Batygin, Batygin, Solar System, New Horizons

Id: GJU5OUYPnO0

Length: 27min 37sec (1657 seconds)

Published: Mon Jan 14 2019