Why Pluto is a Planet with Dr. Alan Stern

before the New Horizons spacecraft 2015 flyby of Pluto comparatively little was known about the cinematic little world in its moon Charon we knew comparatively little about what was in store for the flyby as a result Pluto ended up being a surprise a showstopper with active geology organics and possibly even a subsurface ocean and many other interesting attributes in short Pluto ended up being among the most interesting objects in the solar system while worthy of the title of a planet and the story didn't end there from Pluto New Horizons would go on to show us a trans-neptunian object in the Kuiper belt Ultima Thule which turned out to be a contact binary object - formerly separate objects touching each other unusual indeed and providing much science and insight into these primitive objects that lie in the far outer solar system and perhaps if another object is found that can be visited we may yet get more science from new horizons my guest today is new horizons principal investigator and was present throughout the entire story of her first mission to Pluto and now beyond welcome to event horizon with John Michael Gaudi a [Music] [Applause] [Music] [Music] [Applause] in today's episode John is joined by dr. Alan Stern dr. Stern is a planetary scientist space program executive aerospace consultant and author he leads NASA's new Horizons mission that successfully explored the Pluto system and is now exploring the Kuiper belt in both 2007 and 2016 Time magazine named him one of the 100 most influential people of the year in 2007 and 2008 dr. Stern served as NASA's chief of all space and earth science programs since 2009 he has been an associate vice president and special assistant to the president at the Southwest Research Institute dr. Stern's academic research has focused on studies of our solar systems Kuiper belt and Oort cloud comets the satellites of the outer planets and the Pluto system he has also worked on spacecraft rendezvous theory terrestrial polar mesospheric clouds galactic astrophysics and studies of tenuous satellite atmospheres including the atmosphere of the moon dr. Stern is a fellow of the Royal Astronomical Society he was awarded to 2006 von Braun aerospace achievement award of the National Space Society and the 2016 Sagan Memorial Award as the American astronautical Society in May 2018 his book with co-author David Grinspoon chasing New Horizons was released welcome everyone to event horizon with me John Michael Gautier if you enjoy what you hear fall into the event horizon hit the like button and become an active subscriber by ringing the bell Allen Stern welcome to the program well thanks very much glad to be here now dr. u your spacecraft New Horizons did arguably the coolest thing I've seen in decades at least since the Neptune encounter of voyager 2 now we think i remember after the neptune encounter it was everybody was like well we have one planet left that we haven't yet Sene you know and these these first looks at these planets are not only are the historic they're also really energizing and amazing so at the time everybody's like well how do we get to Pluto how did this start this new Horizons project well it wasn't called New Horizons in the beginning it was really a group of young scientists myself included back at the time that you just described when Voyager finished its job at Neptune and wasn't going to Pluto who knew that the Pluto had a lot to offer scientifically and wanted to see NASA study how to mount a mission there it's a long and involved trail it took it took us 14 years just to find the funding and to get this all started went through a lot of ups and downs but you you know is you know how it turned out it turned out pretty well absolutely and Pluto turned out I mean you know we didn't know that much about it before before New Horizons we just knew that it orbited distantly and its atmosphere you know would freeze out periodically and things like that but actually going out there we find that Pluto is one of the more interesting objects in the solar system were you really surprised with Pluto when when the mission really got going well when we started to see the results I have to say absolutely we had a pretty good idea there are some pretty strong hints that Pluto was gonna really knock her socks off but I don't think any of us anticipated really just how scientifically spectacular it turned out to be you know it's just it's almost impossible to imagine something when it's just a point of light and then to see how complicated and beautiful and perplexing the planet is and it's satellites as well was a joy yeah now that it pays to mention that you know in the run-up to New Horizons we always knew that that Pluto had well not always but we knew who tow had a large natural satellite but in the run-up other satellites were found we're able to investigate any of those yeah in fact them all of those satellites that were found were found by our team using the Hubble Space Telescope beginning in 2005 and the last one that we found was in 2012 and we we look for them specifically with the intent that if we could determine what was there and we're in orbits that we could plan to point our cameras and other instrumentation to study it and that worked out great in fact that we discovered four satellites of Pluto and New Horizons looked at all so we really did the family portrait not just Pluto and its giant moon Charon that had been known for decades but also the four small ones as well now that we're also other surprises with Pluto itself it had Fox and Hayes's that were visible and geologic activity could you go into that yeah the fogs and Hayes's surprised this a bit they've been some talk that some kinds of data before the flyby things that have been seen by telescope on the earth gave indirect evidence there might be Hayes's but not like what we found it really wowed us we found dozens of concentric haze layers in Pluto's atmosphere that stretch up hundreds of miles into the sky and to this day we don't know exactly how the haze forms or how it's so well organized into these dozens of concentric layers and then you know Pluto's geology just blew us away with you know tall mountain ranges and ice volcanoes and glaciers and lots of tectonics evidence of interior ocean and I could go on and on Pluto is it's a little something for everyone there in terms of its activity right down to the fact that it's geologically active today and we don't understand how that could even be yeah especially with it being out frozen you know in this in the outer solar system for a you know a good part of its orbit now given this geology I remember too that there was a basically epic plane of nitrogen that was that was found a whole region of just frozen nitrogen and that was as I recall evidence that there may actually be a liquid water ocean that you mentioned underneath the surface of the eye of the ice so this is sort of like an ice on moon like Europa or insulative what are the possibilities for maybe life being inside that in the ocean in the ocean yeah well you know the surface is very inhospitable for any kind of life as we know it the temperature of the surface of Pluto is 400 degrees below zero Fahrenheit the the atmosphere contains poisonous gases like carbon monoxide and we just don't see any way that life could exist on Pluto's surface any form that we would recognize but deep below the ice there is a pretty good case for a liquid water ocean and if that's right then you know we've got the main ingredients for life as we know it that is liquid water and warm enough temperature to keep it liquid and just like Europa as you pointed out or Enceladus or the other ocean worlds of our solar system where we've discovered these vast interior oceans Pluto is now considered on the list of potentially biologically interesting planets so that's a complete pardon the pun sea change if you will from the way we used to think of the planet when we looked at at telescopically and all we could see was that nitrogen ice on the surface and other ices also evident on Pluto's surface is what looks to be past evidence of liquids on the surface what these have been hydrocarbons like Titan or something else it's not clear we have some evidence for liquid water / ammonia slurries that may have erupted out of the surface and we also have evidence for a place that may just be a frozen paleo nitrogen lake we're gonna have to go back with an orbiter with more sophisticated instruments but also with the time that an orbiter gives you to study every bit of Pluto and its satellites system to understand this New Horizons was a huge step forward but it was only a brief flyby and now we need to go back and and really study it the way that we have studied the closer planets now how has the landscape on that chain because New Horizons took a long time to get out to Pluto as I recall there was a Jupiter gravity assist and basically almost you know pushing the rocket that launched it to its extremes but things have changed we now have things like Falcon Heavy and we have you know this huge SpaceX and Blue Origin rockets that are coming is this gonna give us a faster track to Pluto should we want to send an orbiter out there well in fact you're you're making a really good point these new launch vehicles are gonna help enable an orbiter if it becomes a priority in NASA just announced in the last couple of weeks that it's investing in a study of how to do an orbiter but an orbiter is hard and what makes it hard is that it has to come to a stop what New Horizons did was fly as fast as we could possibly launch it it was the fastest spacecraft ever launched in 2006 and it still is but Pluto's so far away that it took it as you say almost a decade to get there John so in the case of an orbiter but we have to we can fly fast but then we have to slow down and stop and even with the bigger launch vehicles that's likely to mean the same or even a longer flight time just because of all the orbital mechanics and the engineering realities of having to bring it to that stop and I would assume Cluedo doesn't have very much of a gravity well in which to capture an orbiter well you're exactly right that's that's that's correct and unlike the giant planets which can help do the capture because of their gravity Pluto which is only the sizes you know the United States just doesn't have enough enough gravity to stop a probe that's coming at them at super high speed you know New Horizons was traveling almost ten miles a second when it passed blue it seems to me that the Pluto flyby was special because it really captured the public attention everybody was just it was Pluto mania and it had everything even even even just superficial things like a heart shape on it that just you know launched however many internet memes given the public support an interest in Pluto do you think that NASA will if they decided to nor we'll get prioritized I mean lately they're showing interest in the outer solar system there's that you know now proved apparently Titan copter so maybe these do you see us returning to Pluto within say twenty years well I don't know the answer to that the way it works in our field is that once every decade we run a process through the National Academy of Sciences which is kind of funny name it's called a decadal survey surveys everything every good idea it's out there and then ranks them it studies them in detail determines their cost determines their benefit and then ranks them and the top things get funded but there are always a hundred ideas hundred good ideas for every five or ten that you can afford to do so the study that I just mentioned it's gonna tell us what this mission would cost and what it would look like is a very important input to the next decade o survey which in fact starts next year and we'll wrap up with their report about two years from now and if the decade o which is made up of individuals like myself planetary scientists if it if it ranks the Pluto orbiter near the very very top then that mission will happen no almost no question and if other things get higher rankings then we won't see that in the next twenty years and it really just comes down to what the decadal survey decides to do now interestingly it's it Pluto seems to be on the mind of Jim Bryden Stein lately because he declared that it was indeed a planet at least in his opinion just about a week ago as I recall now people are gonna ask me about this because I think most of us out here want Pluto to be a planet what's your views planet or not oh I think I'm in line with almost every planetary scientist there is not every last but most everybody who's a expert you know in the field considers the small planets of the solar system just as much planets as as the big ones of course the reason we're talking about this is because astronomers who don't know very much about planets anymore than I know about black holes and technical detail subject then they famously took a vote which is something we don't do in science it's kind of anti scientific to vote on things you nobody votes on theory of relativity or caught little drift or any other scientific theory anyway to make a long story short not only this is the public considered Pluto a planet but most planetary scientists do and Jim bridenstine the NASA Administrator you're the guy running NASA I think did just the right thing in in stating his view along with us planetary science community that these small planets have all the attributes of planets and people ought to get over the fact that they're just a lot of them that's the university that the that we have that's just data it was the IAU right that that basically didn't try to demote Pluto wasn't it yeah but they weren't very successful this was uh in my view let's see this was in 2006 now it's about to be 2020 so we're 13 going on 14 years later and every interview I do every podcast every television show every radio every you know print media interview talks about this controversy they created unnecessarily now this also goes back even further than that even when clyde tombaugh was still around there was Brian Marsden was running around saying it's not a planet it's not a planet and seemingly had something against tombow almost at least it seemed that way what what are your views on that what was his thinking of her trying to demote these objects as being planets well I am told that I don't have first-hand knowledge did Tom Bowen and and Marsden just personally didn't like each other so you could understand if that's true why Marsden might want to undermine the biggest career discovery of dr. Tom Bell but I don't really know whether that's true or not you probably have done more research on it than I have you know in science there's always differences of opinion about about things is hardly anything in science it's it's unanimous and that's what science is really the way it works is that we question one another's ideas and the best ideas went out from the data and sometimes from computer modeling as well so leaving aside the fact that there might have been a personal grudge or something going on marzin just turned out to be wrong and you know it's very hard to find any scientists it's never been wrong if we work a lot then sometimes even the stuff that comes out of the computer doesn't pan out in the long run turns out that late in the 1990s and ever since we've been discovering that the solar system is just littered with small planets that there are a lot more small planets the size of the United States or continents then then big planets but they're all very far away Pluto was the first one discovered but as we're telescopes and detector technology got better we began to be able to see more and what we didn't know back in the mid twentieth century but did know in the early 21st is that the deep outer solar system made a lot of small planets and Pluto's not an oddball that's out there alone on its own it was the first the brightest and the best well-known of this plethora of what we call dwarf planets and that's not a demeaning term you know we call the Sun a dwarf star because compared to a giant star as it is very small but these dwarf planets really turn out to be the most populous class of planet in our solar system and very likely in the galaxy so you know Marsden died a decade or more ago and I think the field has just moved on yeah I don't think there's a lot of controversy about this anymore it could be said though that Tambov sort of got the last laugh with New Horizons because there was some of his ashes on there which would I suppose mean he would be the first human deceased of course but the first human to visit the planet he discovered and at the same time would be the farthest human from Earth ever to venture out isn't that correct both those things are correct he's also the first human to be launched to the stars because New Horizons is leaving the solar system and I was very proud as the leader of New Horizons to be able to do that it was a wish that Clyde Tombaugh had at the end of his life you know he was in his early 90s when he died and he had said that if a mission ever got launched to Pluto and there's a way that some of his ashes could be put aboard that was his wish and when we got close to launching New Horizons and could afford to fly a couple of ounces of his ashes we reached out to his family and then did the engineering to the little spacecraft container for it and mounted on the spacecraft and make that dream come true it's interesting the actual discovery of Pluto and how time about did that with the blink comparator and you actually cover this in your new book that I mean he must have spent hours and hours and hours just comparing images just to find this thing now you can do it much faster and you know Kuiper belt objects which Pluto apparently is one are found relatively regularly and now we know if as I recall one's even bigger than Pluto right so these would be outer planets a new class of planet first of all yeah we now use computers to do what Tom bout did by I which is to detect moving objects and plot their orbits and that's a much faster and a much more reliable process but Claude was an amazing individual an amazing ability to concentrate looking at these these images of stellar know vast star fields and to find Pluto in it today we use this computer technique and we find asteroids and comets and quicker belt objects and small planets and so forth on a routine basis I do want to correct one thing you said it's correct that technically Pluto is a Kuiper belt object in that it's an object in the Kuiper belt can't deny that but it's not like most quicker belt objects that are the size of counties or smaller it's really a vast place and it's it's large enough to be considered a planet because of the way that it acts it becomes spherical due to gravity the geological and atmospheric phenomena on its surface say all ten it's a planet but so you could call it a quicker belt object if you want but that's more of a zip code to location than anything else I mean technically New Horizons is currently a quite propelled object because it's an object in the Kuiper belt just like Pluto but that doesn't tell you anything about its nature so and it's also used to be thought that we had found planets larger than Pluto out in the Kuiper belt but it turned out that was wrong to this day Pluto is the largest of the planets in the Kuiper belt interesting so that actually got overturned that it's still the the top of the list as far as the small planets of the outer solar system that's right you know what happened was there was another object which we call Eris that some astronomers studying the solar system thought was a little bigger than Pluto the same way that you know the earth and Venus are almost neck and neck and turned out the earth was just a tiny tiny bit larger than Venus when we got New Horizons to Pluto and measured its size more accurately it turned out to be bigger than Eris so Pluto is without a doubt the largest of the planets of the paper globe and we have to take a break I'm joined today by own Stern co-author of chasing new horizons inside the epic first mission to Pluto co-authored with David Grinspoon we'll be back in a minute for more chat about Pluto and the future of new horizons [Music] be sure to LIKE subscribe and share the video and now back to John and we're back with dr. Alan Stern now dr. ok Pluto yielded a lot of surprises but it also yielded mysteries what what mystery of you know that that sort of arose a study of this of it advanced what mystery intrigues you the most it's a really tough that's like Sophie's Choice you know it's it's a conundrum I I would put a group of mysteries at the very top and not choose between them so you know we do not understand we are really flustered by the vast scale of geological activity taking place on Pluto because as a small planet we would have thought its energy budget would have run out by now but it hasn't and we don't understand why we really want to know if that ocean is there and if so how deep how far down do we have to go to sample it we really want to understand whether Pluto's atmosphere comes and goes and collapses and reforms every Pluto orbit or not and you know those are among the the top questions in my book but I couldn't pick any one of them now when you were formulating the agenda for New Horizons you had learned a lot from Voyager the Voyager program that you need to make a smaller spacecraft what was the the logic that went into designing what instrument package you would you would include and how long did that take well those are great questions when NASA had a competition between teams to to see who would get to design and build a mission to Pluto they didn't just say send us your ideas they spelled out what the mission had to achieve in pretty gory detail so they said you have to fit in this cost you have to do it by this date and you have to accomplish the following list of scientific objectives and all those things went into the decisions that that ultimately resulted in the seven scientific instruments on board because you know couldn't spend too much and we couldn't dream about technologies that would make us late on the schedule and we had to accomplish all the scientific objectives mapping the surface mapping the surface composition studying the atmosphere and of course there spelled out in real technical detail in what NASA asked for not just the top level titles like I'm giving you but there was still a lot of latitude for what types of cameras and how many color filters and what resolution the spectrometers would have and many other things and so we as a science team got together a number of times for days on end make technical trade studies and debates so sat along the payload that we ultimately did and then it took about the four years from the time that we conceived it until it was designed built tested and on the spacecraft ready to launch now once you did launch and during the cruise phase between Earth and Pluto what went on what did you guys do with the spacecraft and as I recall getting nearer to the actual flyby there was quite a scare the spacecraft seemed to seize up can you go into that yeah well that's a lot so so bear with me and of course that's what chasing New Horizons the book is all about is the story of how we kind of came to win this project and how we designed it and all of the difficulties that we had and making it ready to the launch pad on time and what we did in flight and you know as we flew it across the solar system one of the ways that we fit in that cost box which was very constraining is that we invented a way to do this with a team of only about 50 people and I know this may sound to some of your listeners like a lot of people but that's the engineering team the flight control team the science team everybody and by comparison when Voyager flew across the solar system to do kind of the same thing but just for other planets it's 450 people on that project we wanted to do it on 50 to get the cost down that those 50 people had to fly to spacecraft calibrate all the scientific instruments navigate plan the entirety of the flyby and as the book describes we actually had to plan for different flybys because we know which situation we would end up with and we got there which so we had to have them all ready to test all those plans and then to be trained for any emergencies that might take place and we had a walloping emergency that took place ten days before we got there when the spacecraft communicating with us and had a computer reset and lost all of the flyby plans in that computer reset you know the book starts off of that story it's pretty heart pounding it would make a great movie but as you know and your listeners know because you've seen pictures of Pluto our flight control team rescued the spacecraft and did it under the pressure of time because there were only days to go after a ten year journey they made it all work out and we had a flawless flyby a flawless flight now the other thing that struck me in the book about New Horizons is the efficiency of the spacecraft I was apparently the transmitter was way less the data rate of Voyager and that allowed you to save up data and transmit it back have you gotten all the data from the spacecraft from the Pluto flyby yeah we have this was a cost-saving measure and it saved us a lot of money but at the expense of taking almost 18 months to get all the data back so we were sending all that Pluto data back from the time of the flyby in mid-2015 until very late in 2016 but that's now three years in the past so all that data's been on the ground a long time has it been studied and gone through yet or I mean could there still be surprises hidden and any data that hasn't been analyzed we have looked at all of the data but the process of analyzing it is a multi-layered process and I'm sure it will go on for another decade I like to make the analogy that you know when a when a patient comes into the hospital with a gunshot wound when they're taken to the to the ER to the emergency room where they triage the patient stabilize them stop the bleeding make sure that they're not going to die right on the spot and then they put them into recovery which could take weeks and by the same token when data comes to the ground from New Horizons we make the initial analyses of it and then put it aside because more data is come into the ground the next day or the next week and we're just triaging those data sets and then after we get all the data to the ground we can start to go back and take a second harder look and do the computer modeling it goes with it but on New Horizons our team is also busy flying the spacecraft farther we did another flyby a not a Pluto but of a building block of planets like Pluto something called a quicker built object just this year now all the data from that flyby is still coming to the ground and will be for at least another year so we're wearing a lot of hats and balancing our time to do all those different things and so there's a lot more work to be done in all those data sets now as you briefly mentioned still on this topic of efficiency New Horizons was not done after Pluto as you just briefly mentioned it went on to look at Ultima Thule which in itself was a barrel of surprises tell us how that came about how did you what is the process of picking the next object that you can get to with a spacecraft like this well it's an interesting process first of all when we were competing to do this mission which we talked about earlier and NASA laid out the objectives that any any proposal would have to be able to accomplish one of them was to go on after Pluto out into the Kuiper belt and to study these little building block objects that are not the size of continents but the size of counties and NASA spelled out those objectives in detail and so we built the spacecraft and the scientific instruments to be able to do that part of the job and then a few years before we got the Pluto we started using giant ground-based telescopes to hunt for these little tiny faint embers these objects that are out there we couldn't find any we looked and looked and look using the world's biggest telescopes and couldn't make it work and then we we started an effort with a Hubble Space Telescope and Hubble came to the rescue and managed to discover three different objects that we could fly to any one of them with our fuel supply and that that decided discoveries was made in early and mid 2014 and then from the choices that we had on the table those three objects and how much fuel each one took to get to and how long it would take to get to each one and how big each one was we chose Ultima Thule and the intercept the flyby was on January 1st this year just literally 33 minutes into the new year and it worked out perfectly not only from a technical standpoint but ultimately itself has just revolutionized our knowledge of how these building blocks what we call planetesimals little bits that come in form before the planets and and which together build up into planets how they were formed and so it's been very productive and as I said a few minutes ago the data's still come into the ground there's a lot more to learn now what's the future are there any other objects that have been identified that and do you have enough fuel to visit anything further well we do have a bunch of fuel in the tank still when it takes empty it's empty there's no filling stations out there but um we've been hoarding the fuel we have more fuel still on board than we used to do the ultimate two we fly by so we're gonna look in fact we're gonna start the search next summer you might ask why it turns out that in the direction that we're flying those constellations against which we're looking for fly by targets are only visible in the nighttime sky in the the months between roughly May and August in a way that we can search for targets so we plan to search in 2020 and 2021 and if we find something that we can get to you know we're gonna do it we have to get permission from NASA to fund that flyby but it's a I think a pretty good bet that that would happen I can't speak for NASA but you know we sent the spacecraft out there to do this kind of stuff and even if we can't find another flyby target there's a lot of really interesting science in the quicker belt that this spacecraft and its telescopes and spectrometers can do as an observatory that's not far away back at the earth but actually immersed in the Kuiper belt and we want to bring as much value out of new horizons as possible so we plan to do that too now New Horizons being so far out you know solar power is not really an option out there so you have to you nuclear power essentially a plutonium pellet that's gonna last a while so New Horizons gonna be active for some time what do you expect that the spacecraft will just no longer have enough energy to continue operations out there well we can that your spot on the the nuclear battery that's on board is operating perfectly so is the rest of the spacecraft for that matter and we have enough power to run the spacecraft for close to twenty more years so the spacecraft should be operating in the late 2030s as a stretchable maybe even twenty forty or so and so we have a long time to continue using you horizons to either do more flybys or to study the Clipper belt other ways it's a lot of time to find an object to study how could you viably you say it say it last 25 years in 25 years from now another object is found would it still be viable to actually do a flyby and everything and do all of the same science that was done at ultimate schooling with an object that far out there are two things that that work against you as you go farther and further out one is that the spacecraft nuclear battery produces less power every year so that means that there are less watts to run things on board and as we get further and further down the road we would have to take turns using different scientific instruments rather than being able to run them all at once so the flyby would would be different for that reason and then in addition as we get farther and farther away from the Sun the lighting levels just keep getting lower and lower lower that in turn means the instruments have to strain more to get there their pictures and their spectra and everything else we're pretty confident that we can do a really bang-up job any time in the next 10 or 15 years but at the very end of life when the battery is running out it would be a lot more challenging so we're gonna try to find something that we can have as a next flyby target in the 2020s and most likely the spacecraft will be beyond the Kuiper belt by the 2030s anyway so the chance of getting a flyby bin is much lower can you do science that far out I mean I know that for example Voyager 1 and 2 which also run on these these nuclear batteries are both still sending back data about things like the heliopause is New Horizons just heading in the wrong direction to study stuff like that or is it you know just gonna forever be until it actually fails within the solar system itself proper is it is it gonna leave it or not it's a good question spacecrafts leaving the solar system and going flying out into the galaxy whether it's still operating when it leaves or not no one knows even if we have continued good health 20 years from now when we're at the far range of our power the edge of the solar system turns out to move back and forth over billions of miles of space and we don't know where that will be in the in the late 2030s when we get there so we can't tell you today whether we'll be outside in the interstellar medium we're still inside the sun's cocoon called heliosphere we will know a few years in advance but we just can't predict that far in advance mathematically where that boundary will be 20 years from now now I have to ask one of the most striking things from voyagers when they turned the camera back on earth do you intend to repeat that with new horizons telescopes we would like to do that and we have the capability to do that but one difference between us and Voyager is that we don't have any way to shield the cameras from the glare of the Sun and they're very sensitive cameras because they're meant to work so far from the Sun out where the sunlight is so faint it turns out that if we look back to take pictures of the planets like voyager did you know take a solar system portrait it could burn out one of our cameras because the Sun is right there in the same direction so we don't want to use the cameras to take the solar system portrait until we're past the possibility of any remaining flybys where we would need them so someday we'll do that but as long as we a chance of getting another flyby we're waiting to do that so on the future agenda maybe one of the last things the spacecraft does maybe one of the last things we would do with it cameras but the spacecraft has other kinds of sensors onboard that study the heliosphere that we just talked about and do other things and so we don't need to wait till the end of the mission we just need to wait until we don't need the cameras for any other purpose all right doctor we are out of time thanks for joining us today it was a pleasure and today I was joined by Alan Stern author with David Grinspoon of chasing new horizons inside the epic first mission to Pluto it's a great read you should check it out what else awaits us to be discovered in the distant outer solar system what was once generally seen as the frozen cold lonely backwater the solar system has now shown itself to have no shortage of interesting objects to explore sparse as though they may be that far out and it seems likely that there are plenty more to be found hundreds are more may still remain unknown and possibly even entire planets many of which may be every bit as dynamic and interesting as those of the inner solar system I can't help but wonder what we'll discover next you'll be happier you've found a scientist that agrees with you about Pluto well what of course Pluto's a planet why not a neutral class of planet a clue not blue not so it's like a box of candy you'd get at the movie theater blue knots does sound kind of good though especially if there are peanuts involved there aren't raisins John just raisins no chocolate you are still on a health week well you took the life out of that one and on that note join us next week for a trip outside the solar system see you then [Music]

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Keywords: Pluto, Why Pluto is a Planet, Alan Stern, New Horizons, NASA, pluto nasa chief, nasa pluto mission, new horizons pluto mission update, ultima thule, alan stern ultima thule, kuiper belt, pluto ocean, nasa pluto planet, pluto planet real pictures nasa, Space, Astronomy, Astrophysics, Oort Cloud, asmr, John Michael Godier, Event Horizon John Michael Godier, Godier, can pluto support life?, rick and morty pluto

Id: t3rtulfdxsY

Length: 40min 46sec (2446 seconds)

Published: Thu Nov 07 2019

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A discussion with New Horizons Principal Investigator Alan Stern of the mission to explore Pluto and if Pluto can support life. As well as his thoughts on NASA administrator Jim Bridenstine’s recent statement that Pluto is a planet.

John Michael Godlier spoke to Alan Stern about his recent book Chasing New Horizons Inside the Epic First Mission to Pluto, coauthored with David Grinspoon.