Kelly Beatty | Preparing for Pluto | NEAF Talks

you you thank you everyone it’s great great great to be here we’re gonna be talking about Pluto today we’re less than three months away from really finding out it’s gonna go and before I jump into that Vinnie mentioned that I’m on the board of directors in the International dark-sky Association which for the past few years has had a booth here they’re not here this year budgets are tight and I’m here to quickly deliver two quasi political messages first is my sense is that very few amateur astronomers the people who have the very most to gain from the darks International dark-sky Association success are actually members may I see a show of hands of those of you who are members of the ID a thank you very much and that’s not very many of you second thing I want to mention is that right now all across the country thousands of communities are determining or planning to switch their street lights to LEDs now LEDs can be very very good and they can be very very bad Davis California has a situation where the town installed LED streetlights that were so bad they actually had a recall if you will in the town is having to redo them I ask you on behalf of the IGA to find out what’s happening in your towns be proactive if you don’t want to stand in front of the City Council to fight for for high quality lighting that’s fine let me know I’ll be happy to do it for you okay on to Pluto first a little background yeah you know this is going to be old news for some of you but we live in a remarkable solar system with an incredible diversity of worlds these planets all form together and yet they ended up so very different we’ve got little rocky ones near the Sun we’ve got big gassy ones in the middle we’ve got ice giants out beyond that we’re not really sure how they formed we’re if they even formed where they are now probably not but what we do know is that there is this great diversity who are the gas giant planets the biggies here are there’s a kind of a cartoon that shows in this in crude terms Rock in this diagram is like rock and metal things that are solid at most temperatures ice is all of the things that are what you would call volatile it’s not just water ice but carbon dioxide ammonia things like that and then gas is almost in this case hydrogen and helium I teach astronomy in high school and I tell my students if you don’t know the answer to their question just answer hydrogen more often than not it’ll be correct so you can see there’s this variety of of compositions but even among the major planets though they have their style they’re they’re this host zu of these smaller worlds of different sizes and shapes and and this is I couldn’t in this list a couple of you see the moon down here it’s not nearly the largest of the satellite Titan and Ganymede are satellites that are bigger than the planet Mercury just remember that thought and then down here is Pluto out at the edge of the planetary system so this this set of worlds that we have you know the ancients knew about six of them if you count the moon is one of those and and then we realized that there was kind of a hole here some of you know about the tshis vote log which might not know is that in the late seventeen hundreds european astronomers were so convinced by the tshis vote log that there was a missing planet that they said about to find it they called themselves the celestial police and

that’s a whole story for a different time but on January 1st of 1801 of an object was found in here that we now know a series very first look good looks at series thanks to the dawn spacecraft and then Oh mark Raymond will have a lot more to talk about that later this weekend but series and and the in very quick succession series Vesta Pallas and jr were discovered and they turned out to be the some of the for the very biggest objects in the asteroid belt and so astronomers thought oh look we’ve discovered four new planets and so they got their own symbols they got included in tables no more were discovered for a while and then they started being discovered by the dozens and hundreds and we came to realize that these are not planets that they are objects in that belt that we’ve come to know pretty well here you’ll see more of this later but this is what series looks like close-up ask ask mark Raymond about this little white spot here we think Ceres has a lot of ice in it and that might be an exposure Vesta we know to be a planet with a sort of volcanic igneous surface and I show you this here’s a whole bunch of other asteroids that we have actually visited so we have a pretty good idea what the asteroid belt is all about and we’re completing the inventory of the solar system and one of those objects that has just been too far away to get to until now was the planet Pluto so let’s talk about Pluto who does a very interesting husband interesting object from the get-go it was at as were as was Neptune Pluto was predicted to exist before it was actually found John Herschel thought that there was a planet out beyond Neptune after he discovered Neptune and then things that he really heated up about a century ago when William Pickering who was an excellent planetary observer and Percival Lowell who had a lot of money to become a planetary observer were duking it out in terms of their predictions for Planet X and they did the mathematical calculations yeah I think you know the story Neptune was predicted to exist because of the perturbations it had on Uranus orbit Uranus was not going the Sun in the smooth way that it should so mathematicians two different ones predicted that there must be another planet out beyond Uranus lo and behold there was a snap tune it’s big its massive it did exactly what it was supposed to do but the calculations suggested that it wasn’t quite taking care of all the motion in Uranus orbit there must be another planet out beyond Neptune and that’s what these predictions centered on well Pluto was discovered in 1930 as the result of an intentional search by Clyde Tombaugh very young Clyde Tombaugh who had come to aid this plant search at Lowell Observatory and Tombaugh turns out got really lucky fairly early in the process Harry is as a young man he had impressed the Lowell Observatory astronomers for his ability to create careful meticulous notes of his observations something that is still a value today this is the telescope that he used to discover Pluto with his was a really exciting and yet miserable life by night at Lowell Observatory and Flagstaff which can be a very cold place in the winter he exposed big plates with this telescope and a couple of days later he would go back to the exact same area of the sky and expose more place at that same area the thought was that if there was a planet out there that the planet would shift a special contraption called the blink comparator was made so by night he was taking these plates and by day he was blinking back and forth incessantly these giant plates full of thousands of stars carefully looking at each section until he found found something that moved here’s the discovery plate for Pluto it’s not this it’s this very very tiny those of you who have tried know that Pluto was a very challenging object to find in a telescope visually Harbor that hangs around 14th magnitude and in in this case it turns out that Pluto was fairly close to where Lowell had predicted it would be because that’s where Tombaugh started his search as it turns out as you’ll see Pluto is not nearly massive enough to have affected the orbits of Uranus and Neptune it was just down in the mathematical noise by sheer luck

Percival Lowell had predicted in the right area of the sky and by sheer luck Clyde Tombaugh swept up Pluto early in the search this is what he looked like at his home in las cruces a few years before his death his trusty old telescope is with him I was really happy doing and honored to get to know him a little bit before he died in fact he made one trip out east to Boston and he stayed overnight at my house he and his wife Patsy and so we’ve sold that house since but the last thing we did before we closed the door and turned over the keys is put up this plaque yes it doesn’t say whether Pluto is a planet or not okay so Pluto was discovered and it was the first planet discovered by an American a Lowell Observatory made a big deal about this they were great at the PR and eventually settled on the name Pluto which had been suggested by a young schoolgirl in England as it turns out and and yet almost immediately it became clear that Pluto was not the earth-mass object that they had thought it would be so it became clear pretty soon in the years after its discovery that by just by following how bright and dim it gets over time that it has a light curve which means that we can determine how fast it rotates and the rotation period turns out to be about six days but that rotation period changes over time the the the peaks and valleys get brighter and deeper which means that either either the surface is changing or maybe the aspect that we’re looking at Pluto is changing it was all very strange and mysterious not long after that it was it was realized by yet dynamicists that Pluto’s orbit crosses the orbit of Neptune and yet they can never collide they’re in what’s called a resonance Pluto goes around the Sun in about 248 years in two trips around the Sun Neptune goes around the Sun exactly three times their lot in that relationship and that relationship keeps Pluto from ever running into Neptune even though you can see up here their orbits do cross of 1979 to 1999 a napkin was the farthest planet in the solar system because Pluto was actually closer to the Sun than Neptune was and here’s where it starts to get interesting in 1976 do Cruikshank discovered a very strong absorption from methane methane ice on the surface of Pluto that’s what the ch4 czar in this is a near-infrared spectrum this is right at the beginning of near-infrared strana me four professional astronomers and they discovered that there yes there’s water ice but there’s also methane ice now here’s why that’s important Pluto is only so bright it’s fourteenth magnitude it’s a lot dimmer than it should have been so either Pluto is really a big planet that’s black or it’s a very small planet that’s white they would reflect the same amount of ice a same amount of sunlight and this discovery meant that they had to be a very small object that was fairly bright and reflected okay so that tells us a little bit about its size but not exactly the kicker came in 1978 when James Christie using images taken at the Naval Observatory took a imaging photo this is enormously enlarged and saw a bump on the side and the bump moved over time one side than the other than one side that and the other every six days to match the orbital period that we nuclear had and we concluded they concluded Krissy concluded that Pluto must have a satellite now you know Pluto is named for a god of the underworld and so it was this whole naming thing is very important to astronomers as we’ll see and so Christie was trying to come up with a name that was consistent with that and he came up with the name Terra which is another god of the underworld except that so if you asked somebody how to spell that name CH AR o n right those who don’t know the story will say well it’s Karen that’s how they pronounce it in Greek but those who know the story will say no it’s Sharon because Christy’s wife was named Charlene okay so fast-forward to 1985 it turns out that Pluto and Charon are orbiting not kind of like this like the rest of the planets are around each other but like this and it turns out that in 1985 the the orientation of Karen’s orbit Sharon’s orbit was going to line up directly with their such that it passed in front of them behind Pluto repeatedly every six days this is good news because

but those of you who have visited the iota the occultation timing association booth you can learn a lot about an object from occupations and so astronomers measured the dips the little dip when Sharon passed in front of Pluto and the bigger tip when it passed behind Pluto over and over again and came up with new estimates small or even smaller estimates for the size of Pluto and Charon and so here here is the tale of the tape when it was first hypothesized astronomers thought that Pluto’s mass might be as much as ten times that of Earth when it was discovered even by then their their expectations had lowered and by the time methane Ison and Charon were discovered now we’re talking about an object that is only a few thousandths most the mass of the earth okay these are very small objects this is an older graphic from sky and telescope showing their comparison with the United States they’re not big at all all right so Pluto is small but it’s got seasons turns out it’s got an atmosphere turns out it’s got surface markings as seen through the Hubble Space Telescope now these are not Hubble images just to be clear these are maps made from Hubble images and I’ll show you how bal image in a bit but that pluto has the this is what’s causing the light variations as it spins it gets brighter and darker and the spots are moving around there’s seasonal motion caused by things frost evaporating one place and ending up another or maybe there’s clouds we don’t know yet we’re about to find out all right so Pluto was kind of going along being this interesting place it’s got the moon it’s got an atmosphere yeah it’s small but it and and we don’t really know how it got there it’s in this resonance with Neptune then things started getting messy with the discovery in 1992 of an other object out beyond Neptune that came to be called qb1 that’s a shorthand eventually these things get named but Dave Jewett and Jane Lew who discovered it here we are more than twenty years since they have yet to actually offer a name for it the point is that qb1 was just the tip of the iceberg of literally thousands of objects that we now know exist out beyond Neptune in what is called the Kuiper belt by the way I know many of you give talks some of you might know the name covert Schilling who’s a very good science writer I just visited Harvard in the Netherlands and Gerard Kuiper was also from the Netherlands I said covered how do you really pronounce it he says it’s calper Halper so there you go we’re paradigm changes underway right now anyway the Kuiper belt calper belt is part of a large trillions of objects out beyond Neptune that are leftovers from the beginning of our solar system and it seems then that Pluto is just the largest of these at least the largest one that we found there’s still some thought that there could be objects out there lurking in the in the Kuiper belt that are even larger than Pluto and we just haven’t found them yet so the discovery of all of this started astronomers thinking well you know Pluto should be considered a minor planet an asteroid and that’s where the talk started in 1992 and it got so bad that eventually the IAU actually had to step in and say look enough of this talk Pluto’s a planet that’s it we’re gonna call Pluto a planet history is telling us that politer should be a planet so we’re gonna keep that way okay so the the the main protagonist for this was a guy named Brian Marsden you’re seeing here is he’s shaking the hand of Brian’s on the right Clyde Tombaugh is on the left they met at Harvard I happen to be there with a camera they are both smiling at least for the moment but but Brian was the one who was who really started pushing this notion of Pluto may not be a real planet and the IU stepped in and said no Brian we’re gonna call the planet but then in 2005 the game changed again Michael Brown and some others discovered an object out in the Kuiper belt that is very large as large as Pluto or bigger and they had all kinds of nicknames for its smiley and not smiley Xena right warrior princess how was the nickname it but it really did need a formal name and therein lies the problem within the International Astronomical Union there is a committee that names asteroids and there’s a committee that names planets

so before they could turn it over to the correct committee they to decide what it really was and many of you know the story here is there’s a sort of comparison of Eris and Pluto with some other objects that have since been found in the asteroid belt in the Kuiper belt and there’s a lot of big objects out there but only Eris rivals Pluto in size so we needed to know which committee to send errors for to fork or approval and so in 2006 it all came to a head some of you know this story this happened to be a meeting that was held in Europe and European astronomers have word on the street is that the Europeans are still a little upset that the Americans made such a big deal about Pluto and so they they debated long and hard whether Pluto should be considered a new class of planet this dwarf planet and they’ve used props is it a big tent that everyone’s a planet or is Pluto on the outside looking in interesting thing about the IAU many thousands of astronomers are members but only one can represent each country and they get a yellow card and so this is the vote this is the vote to accept Pluto’s demotion to dwarf planet status now what does dwarf planet means the IAU in this resolution actually defined where the planet would be it’s an object that is in orbit around the Sun so I guess that means that all the thousands of planets that we have found now orbiting other stars don’t count and interestingly they didn’t define what the top size end of a planet must be which is actually fairly well defined you know they had that they were fixated on the small end so it has to be has to have enough mass to be round and this this is a pretty simple concept you’ve seen lots of pictures of craggy little asteroids and such that’s because the mechanical strength of their rock is stronger than the the the pull of gravity to try to pull it into a spherical shape but if you get big enough eventually gravity wins that argument that that fight and and gravity pulls all the mass in your beer more or less and so it has to have enough mass to be round it turns out that’s about six or seven hundred kilometres across depending on the mass of the object and here’s the kicker it has to have cleared the neighborhood around its orbit it has to be masked what they intended was there has to be enough mass so that if there’s some other smaller object lingering around its gonna that smaller object is gonna get kicked out the analogy I like to use as is you all remember back to your school days or if you’re young enough your current school days and there’s a big bully who’s who’s he and his posse or like gambling across the the school playground do you go right up to that bully and say hi no you stay as far away from that bully as you can that’s clearing the neighborhood and that’s what they meant by clearing the neighborhood around Pluto Pluto did not meet that criterion it’s not massive enough to do that one of these is considered massive enough that’s Ceres Vesta is not we’ve seen these now both up close and personal earth is earth the planet desert the planet well yeah except that if we put out if we put earth outward neptune out where pluto is it wouldn’t be mass in the massive enough to clear its orbit so it wouldn’t be considered a planet okay that’s the Pluto story now let’s get on to the discovery story and the discovery story is gonna happen very soon and we’re gonna know exactly what’s going on with Pluto and exactly what it’s all about there’s a spacecraft called New Horizons which has been enroute to Pluto since 2006 January of 2006 here’s its launch it was launched from Cape Canaveral it’s a it was the fastest object ever to leave the earth it crossed the moon’s orbit in only nine hours after launch it was really heading out of town as a little aside the unfortunately it was launched while before Clyde Tombaugh it launched after Clyde Tombaugh died but his no Patsy was still alive New Horizons spacecraft carries a small vial of cremains of clyde tombaugh so it’s gonna get to see his planet it made a pit stop flying by Jupiter really just a year later and used that to pick up speed to get out to get out to Pluto it did a lot of great science that Jupiter nobody remembers really New Horizons did fabulous science we hadn’t been to Jupiter with a spacecraft since Galileo

in the mid 1990s so we saw a lot of things new or again this is a little gif animation of a volcano erupting at the top of Io credit to commuter aizen’s well we’re getting near its actual objective which is to fly past Pluto and Pluto’s family this is a that has a really great long telephoto lens on board called Laurie and Laurie has a focal length of about 2.6 meters so it’s a very powerful colorful telephoto and this is showing from last July Pluto and Charon going around each other here’s a more recent one showing clue tolling Karen and just from really a couple of weeks ago and I want you to notice that Pluto is not staying still there they’re actually both orbiting around their common center of gravity so this is this is very interesting we’ve never really encountered a situation where you know the two objects the main two objects are so close in size well when when New Horizons was being designed Pluto had only one moon then in the year before it was launched we discovered two more moons which came to be called Nix and Hydra thanks to a Hubble Space Telescope images and we now know of two more moons even smaller called sticks and Kerberos and why is this important it’s it’s like a bonus time right instead of just photographing Pluto and Charon we get to do these other moons too the problem is this these moons are so small probably just a the smallest one it’s just a couple of miles across that if something hits them a little impact the dust that is raised these objects don’t have enough mass to bring the dust back so the dust escapes so that means that there could be dust particles all around this system and flying through the system at you know nine miles a second up a small particle of dust hitting the New Horizons spacecraft which could be catastrophic so it turns out that so astronomers got really worried in a hurry and and they they concluded that the safest place to fly through this system would be near Karen’s orbit here here near the inside because Karen would serve to kind of sweep up these particles how did you do it clearing that’s exactly where New Horizons is going to go so it’s going to go fairly close by this is the time line it’s going to be a very quick visit and don’t expect a steady stream of pictures coming back from the spacecraft it’s gonna be this is gonna be on July 14 if you can’t remember that data’s best deal day and it’s gonna be a very quick visit that the times did you see along the yellow line are in Universal Time it’s being controlled by the control center not at the Jet Propulsion Laboratory but actually at the Johns Hopkins University Applied Physics lab down in Maryland it’s going to come within about eight thousand miles of the surface of Pluto about fifteen thousand miles of the surface of Karen and then some two very interesting things are gonna happen again I mentioned these occupations before when after it’s gone by of New Horizons is going to fly into the shadow the shadow both of the earth and of the Sun when it when it flies into the shadow of the earth a radio beacon from the earth is going to be passed to the spacecraft in just as its but earth is about to set that radio beacon will pass through the atmosphere of Pluto which we know to exist and Charon which we’re not sure and that will tell us the extent and the density of any atmosphere around Brown Sharon and and Oberon Pluto then meanwhile it’s also going to pass in in the shadow as seen from the Sun and as the sunlight passes through that atmosphere we’ll be able to tell something about the composition it’s a great whole technique so here’s our spacecraft it’s got seven experiments RTG Epirus stands for the radioisotope thermoelectric generators the plutonium that it carries to create the electricity to run there is a an experiment called Ralph and then the experiment called Alice and yes they are named for The Honeymooners but it’s a very powerful instrument suite we’re going to have terrific images we’re gonna have spectra we’re going to have magnetic fields solar wind measurements one of the things that astronomers think is happening is that Pluto is so low mass that a lot of its atmosphere is escaping we’ll be able to measure that so here that here are the players for this upcoming flyby sort of

scale using the moons of Saturn and I thank Emily lakhta Walla from the Planetary Society who put this together so using moons of Saturn as proxies this would be Pluto here Sharon and the other four little satellites and they might look something like that when we finally get to it now Sharon we mentioned Pluto and Charon a couple of times this is a simulation of how share on my deformed by something big hitting Pluto long ago and the color represents heat here and the the collision spits off a blob that stays in orbit and that’s probably how Sharon came to be formed and why Pluto’s entire system is tipped up crazy like it is the problem is we’ve been studying this place for a very long time and we know so little about it really this is the very best Hubble Space Telescope image it’s about eight pixels across New Horizons will exceed this come about May and we’ll start getting pictures back that are better than pictures again here’s that that nap we know that the surface of Pluto has very dark areas which are probably like organic tari goo we know there’s we know there is a methane there so when sunlight strikes nothing it’s easy to break apart into the carbons and hydrogen’s and they recombine to make goo all right that’s official and and so we think that the surface really is tainted orange from some of these compounds and there are bright ices it’s going to be a very interesting place you have no real idea how what its gonna look like some artists have taken a shot here’s here’s one portrayal right down here Pluto kind of orangish share I’m kind of whitish Sharon doesn’t have any methane on it it’s just water ice here’s another portrayal this is by Casey Reed who does a lot of the artwork the sky telescope we have a big article about this by Emily locked a wall in the July issue coming up so you’ll have your your preview your program and very very soon this stamp will be obsolete I’m really looking forward to that this has been 85 years in the making this this flight it’s been 25 years 26 years since scientists first proposed a mission to Pluto and it and it’s taken this long to actually get it out there now New Horizons mission won’t be over by the time it goes past Pluto it’s it’s supposed to be observing the Kuiper belt too and so after it goes past Pluto it’s going to home in on one or two Kuiper belt objects that may have been discovered yet by the Hubble Space Telescope and maybe not but in any case here we’re going to be seeing at least six or seven new worlds for the very first time of a very different sort getting back to those early slides there’s the inner planets the inner rocky planets that’s the first zone of our solar system there are the world’s better giant Jupiter Saturn Uranus Neptune the ice and gas that’s the second zone we’re now going to be exploring the third zone of our solar system for the very first time it’s going to be an incredibly exciting time and I’m sure you’re all going to be eager to see the results from that so thank you very much for your time you my first experience with us from aging

was in the 80 with a silver film and it was quite painstaking my parents day the bolts the celestron eight and they let me my hobby and I was the happiest teenager of the world I was dreaming in front of the brochures with all all the telescopes first major discovery was in 2006 on a February 24 Universal Time 25 local time it is during that time when I took an image of Jupiter and I discovered that it’s white spot oval ba has turned red this spot is now known as a red spot Junior I had some people saying that where the hell are you wasting your time at in the middle of the night just you know imaging planets and this is where amateurs fill the gap and this is how we contribute basically to the development of the science of astronomy celestron has always been about imaging when I got that celestron 8 back in 1975 one of the things that attracted me to it was it appeared to be built from the ground up to adapt directly to photography the modern electronic imaging makes it so much easier for anybody to get into this and achieve good results quickly people saying oh I just started imaging in 2008 and they’re producing Observatory quality work or I’ve only been in it for 10 years or whatever and I’m thinking my god I’d already been doing it for almost 4 decades by the time they even started so though that’s really been a joy to me that the passion that I’ve been able to enjoy for five decades now everybody can get in and do top-notch work right off the bat here The Rock case was one of the first cases I used a microscope in and it became a huge case and sometimes it’s not the actual evidence that’s there that leads you down a different road sometimes it’s what’s not there so it’s just it’s just things like that that may seem unimportant at the time but become very important when you’re testifying at trial and I wouldn’t be able to confidently testify to things like that without the use of the technology of my or skill they’d be great for a curriculum because these students come in with very little knowledge of using microscopes and trying to teach them on a standard microscope is very difficult because you can’t see what they’re seeing I think with students today they’ve grown up with technology they expect technology and then they get the classroom and there’s no technology so having that technology there I think makes it feel more real to them and I think they’re just everyone’s fascinated by microscopic things anyways with these microscopes and the nice big large size of the panel everybody can see what they’re supposed to be looking at I do love that everybody can be involved and we have six of them and so easily the entire class can be looking at different parts of the same insect or the same slide all at the same time so sharing has just been really a plus and there they love it they’re so involved in what they’re doing because the microscope is fun to use I think introducing birding and bird-watching to other people is very important to the to the recreational activity of burning the spotting scope is great the celestron regal spotting scope is it’s really versatile and one of my favorite things to do with that is digis scoping and so that it’s it’s great you don’t have to carry your your bulky camera around you can just I carry my iPhone with me and that’s I do a lot of my photography with that and what the celestron scope is just a clear picture very competitive by nature got into imaging and I wanted to be good at it obviously and just like with the golf and anything else really but it’s funny with just like with golf there’s all different types of people trying to fit in you know my hobby with being a golfer and a dad and husband I mean it’s tough and so I’ve learned to process very very quickly become very efficient at it and some guys what’s been you know a week on one picture crankin went out you know over coffee in the morning developed our spirit but yes streetlights have a few emission lines

primarily sodium and mercury that can be selectively filtered let get your shade apart on Mars with this telescope you’ll be able to see the polar icecaps you will also see some dark area features celestron has been instrumental in our support of teachers in their quest of bird wash and identify birds and and engage students in bird-watching they’ve donated many pairs of binoculars to the Cornell Lab of Ornithology spurt sleuth k12 program and we’ve been able to pass along these binoculars to teachers kids loved tools that they can use to do science if you put a pair of binoculars around their neck they become scientists you you