Alan Stern: “What If We Return to Pluto?”

Alan Stern: “What If We Return to Pluto?”


– Hello, good evening. It’s great to see everybody here. It’s a delight for me
to introduce tonight’s Ideas Festival speaker to you. I’m Steven Collicott,
I’m a Professor in the School of Aeronautics and Astronautics in the College of
Engineering here at Purdue. And I am also the Associate
Head for Engagement in the school and so introducing such an engaging speaker as
my friend, Dr. Alan Stern tonight is one of my very enjoyable tasks. Our program tonight has two parts. First will be a presentation by Dr. Stern and the second part, we have
some question and answer, and you’ll see the
microphones down front here. You’ll need to come down front to those and Alan will, he’ll
point at whose turn it is. This event is recorded and live-streamed, just for your information there. We do ultimately have
a time limit tonight. I will be the bad guy
who comes out and says, “Okay, we only have time
for two more questions,” and I apologize in advance for that. So Dr. Alan Stern is presently the Associate Vice
President of Space, Science and Engineering Division at
Southwest Research Institute in Boulder, Colorado. But that job title is really far too bland to describe what Alan does each day. We welcome Alan here in his role, his much better known role
as the principal investigator of the New Horizons mission, which means he is the top person, starting with writing
a successful proposal with the team, all the way through all the science content
and the mission operations, and so what a remarkable job. And New Horizons, of
course, is a team effort, and I want to point out
to our students here, much like the student teams that launch suborbital science payloads, such as on Blue Origin and other
commercial suborbital rocket companies, it’s just like what our students are doing. So Dr. Stern’s resume is
both lengthy and impressive and is too lengthy to detail here. So I just want to point out a
few recent highlights for you. Alan was appointed by
our nation’s leadership to serve on our country’s
National Science Board, which directs our National
Science Foundation. In the next few months, Alan
will complete his duties as Chair of the NASA Planetary
Protection Review Board. And another highlight, Alan has served as the NASA Associate Administrator of the Science Missions Directorate, which means he was in charge of all NASA science missions and basically reported to only one person,
the NASA Administrator. And so honestly, this list
of Alan’s achievements goes on and on. So I’ll stop here with
this very abbreviated list and ask you to welcome to
Purdue’s Ideas Festival and our Sesquicentennial,
the principal investigator of the historic and the most astounding New Horizons space exploration mission, Dr. Alan Stern. (audience applauds) – Thanks, Steve. Steve, Dr. Collicott,
you’re going to need these. – Oh, yes. – Hello. Well, thank you, Steve, for
that great introduction. It’s great to be here. The last time I was at
Purdue was 10 years ago, so it’s great to be back,
great to talk to you about my favorite space
mission of all the ones I’ve had the privilege
of being involved in. I probably don’t know most of you, so I thought we’d just
get this out of the way right away, just see what
kind of an audience this is. Could I have a show of hands up front for whoever thinks Pluto’s a planet. Okay, good crowd, okay, all right. (audience laughs) All right, so what I’m going to do is talk to you a little bit
about this whole mission, this whole enterprise
that ultimately involved 2,500 men and women to pull this off, the farthest exploration in
the history of humankind, the farthest worlds ever explored. This picture is a true
color picture of Pluto taken by the New Horizons
spacecraft on the morning of Tuesday, the 14th of July,
2015, just hours after making the first exploration of
Pluto and its system of moons. This picture was taken
when the spacecraft was in the shadow of Pluto for
one of our experiments, and it’s looking back at
Pluto with its atmosphere in true color, it really is a
blue sky, backlit by the sun. And this is not the most
scientifically important image of the mission, by a longshot,
but it’s my favorite. It’s absolutely my favorite. First, I think it’s hauntingly beautiful. But second, it also has
some special meaning. How many of you have seen,
again a show of hands, how many of you have seen
those famous Apollo 8 photographs of the Earth rising over the limb of the moon, right? That meant we were really there. I worked on this project
from its inception in 1989 until 2015 to get it
done, that’s 26 years. This picture is taken from
the far side of Pluto, and it took 26 years to get
to the far side of Pluto, and that’s why this picture
is absolutely my favorite. But don’t worry, I’ll show you many more, and I’m going to tell you
about many of the things that we learned from
this truly epic journey, in which we designed
and built a spacecraft and flew it all the way
across our solar system. Now that sounds like science
fiction, but it’s not. People working hard, mostly engineers, but also flight controllers and scientists and accountants and secretaries,
public relations people formed the team and did
something larger than life, because they were a team. And this is the story of New Horizons. So I have a little bit of
time to tell you about it. I’m going to do that. And then I’m going to tell you
about some of the nerdy science, some of the things that we discovered. And then we’re going to talk
about what if we return. What if we sent a spacecraft
back to do a more in-depth job. I’d like to start with this picture. Who knows what this is? It’s the best picture of Pluto ever made before New Horizons. This is it, this is all we had. And it’s just a blob,
it’s just a blurry blob. And this picture was
taken with the biggest and the baddest gun we have in astronomy, the Hubble Space Telescope. You cannot do better. But because of Pluto’s distance, billions of miles away, literally billions of miles away, this is all you get. Now I heard some people
chuckle, it’s okay. I took this picture with the Hubble. I was principal
investigator of this program and I can tell you, this
picture was revolutionary when it was first taken. It was the first time
Pluto was ever resolved, other than as a point of light. And from this, we wrote scientific papers that were peer reviewed and published, a whole series of them. Can’t you see the northern polar cap? (audience laughs) Right, really, this is tough to work from images like this, and this is why we send spacecraft to the planets, is you have to go there
and be much closer. And I’d like to illustrate that point. Here is a beautiful picture of a planet, our planet, the Earth,
taken from close range. And with an image like this, you can tell what’s going on. You can learn that there are continents and oceans and weather patterns. You can learn a lot from just
a single image like this. But how about that blurry image of Pluto? Not so much. A few years ago, right around the time of the Pluto flyby in 2015,
I asked one of my postdocs, Amanda Zangari, to take this picture and pixellate it to the same resolution as the Hubble Space Telescope
best ever image of Pluto. There it is. Now what could you learn from this? It’s pretty obvious, not much. Again, this is why we go to the planets. And I want to just drive
that point home one more time and show you this. Who knows what we’re looking at? I heard Mars. That’s a good try, but
it’s completely wrong. (audience laughs) You see, you really can’t
tell unless you go there. So it took a long time to pull this off. I said that we started in 1989. I was in graduate school. First of all, it’s a
very expensive enterprise to do planetary exploration. So you have to raise, in this case, about a billion dollars. And it took a very long time. It took us 14 years to get
approval for the funding. And we had to try many different keys to try to unlock that door. And for the people who were
at it at the beginning, making the scientific case
for why we should do this, we went through a whole series of studies, and you see those there. There’s Voyager on the
left that was the precursor to new Horizons, but
then there was Pluto 350, and then Mariner Mark II,
and then Pluto Fast Flyby, and so forth and so on. And every one of those
failed to ever get off the drawing board, to ever get funded. We tried different
approaches that delivered different amounts of
science at different costs with different speeds for the mission and other combinations of parameters. Only New Horizons, the
right-most spacecraft drawing in that picture, ever got
off the drawing board. All the rest were just paper studies, but every time that we failed,
we had to look at ourselves and say, “How bad do you want this?” “Because that didn’t work,
if we really want to do this, “we need to try something else.” That was pretty easy the
first couple of times. But it really took persistence. We could’ve walked off the stage. We could’ve, after two or three tries, said, “We tried everything
we can think of.” There’s that old fighter
pilot saying, you know, the plane is crashing, and he said, “I’ve tried A, I’ve tried B, I’ve tried C, “I’ve tried everything I can think of, “now what do I do, what
do I think of next?” And that’s kind of how we treated this. We really went to the mat for it. And there are a few dozen
people in this country who stuck with this from 1989 until 2003, when we got it funded. The reason we really
ultimately got it funded is because of a very important discovery, maybe the most revolutionary
discovery in my field, in the field of planetary science, in the late 20th century. And that was that unlike
the way that many of us were taught, the solar
system does not just consist of four little
rocky planets near the sun and four giant planets,
Jupiter, Saturn, Uranus, and Neptune, somewhat further out, with a little footnote called
Pluto orbiting farther. Pluto actually turned out in the 1990s to be the first discovered
of a whole population of small planets we
now call dwarf planets. And you see these worlds here. We believe, we have discovered
almost two dozen of them, they’re the size of continents. Pluto itself is about the
size of North America. So it’s a big place. But these are still much smaller worlds. And we believe, from forensic evidence around the solar system,
that the solar system made several hundred, or possibly a thousand, of these dwarf planets. And when it was realized
that that completely reshaped our view of how planets form
and the population census of our solar system, when we realized that all of the first five decades of planetary exploration had concentrated on the four rocky terrestrial planets and the four giant
planets, but we hadn’t been to the most populous class of planet in the solar system, that’s what caused our National Academy of
Sciences to rank this as the number one priority
for planetary exploration, is the first mission to the dwarf planets, the first mission to this whole new class. And then NASA conducted a competition. So NASA announced that there would be a mission to Pluto and any team could form and send a proposal in by a certain date, as long as that proposal
met a certain list of scientific objectives and could fit within a certain cost
cap and could accomplish the mission by a certain date, which by the way, was the year 2020. And as long as you could
meet those three criteria, anybody could propose. So we formed a team called New Horizons and there were competitor
teams from other institutions. And all of us had the same amount of time, and we turned in proposals
that were about that thick, like an old New York City
phone book or something, with engineering designs
and project designs and budgets and management
plans and everything else. And then NASA had experts
review all those proposals and they conducted oral
examinations and quizzed us on the things that we weren’t clear about, and at the end of that process,
they selected our mission, New Horizons, in November of 2001. Now there’s an old
story, it’s a true story, by the way, that the
day that John Kennedy, President Kennedy, announced that the Apollo program was being started, which NASA had wanted for years, to land humans on the
moon, that the head of NASA called a meeting of the
senior staff and said, “Well, we got what we asked for, “now what do we do?” That’s how we felt when
we won New Horizons. Because the award letter
that I got from NASA, “Dear Dr. Stern, we are
please to inform you,” gave us a budget that was only 20% of the budget of Voyager, two dimes on the dollar. So we were basically asked to do something that had never been done before, not just go to the farthest worlds, but to do it at a
breakthrough price point. And we were given a launch window that was only four years in the future, about half as long as any
previous deep space mission like this had taken to build it. So we had to do it twice as fast, five times less expensively. And so then we got started. And to make this work, we
had to make many compromises. I like to think they were
intelligent compromises. For example, we built a
fully redundant spacecraft so that every system is twinned inside. There’s two sets of
thrusters and two sets of navigation units, two sets of radios, two sets of everything, with only a couple of exceptions. But we couldn’t afford two rockets and two spacecraft. So unlike Voyager or the
Pioneers, or if you know the history of robotic space exploration, unlike those early
missions, like the Mariners, we couldn’t afford to fly two in case one didn’t get it right, or one blew up at the launch pad, or
one failed in flight. We had to build a very
reliable single spacecraft to do this. We had to make other choices. I’ll give you an example. On the side of that spacecraft drawing, sort of towards the top,
and I don’t have a laser in my hand, but you see
that gray affair that’s sticking out, looks sort
of like a hair curler? It’s not a hair curler, it’s
a nuclear power generator. And because we’re going
so far from the sun, we couldn’t afford, there’s
no way to use solar arrays, because the sunlight is so faint. But those nuclear power
generators, called RTGs, cost almost $100 million a pop. Couldn’t afford to have
two, like the Voyagers. Or four, like the Cassini probe to Saturn. We could only afford one. So we had to make compromises
in our communications system to get it in the power budget,
’cause we could only have a certain amount of
power, in order to make the mission affordable, that
gave us very low data rates. So then when we got to Pluto,
we knew it would take us more than a year to
transmit all the data back to the Earth. Had we had higher power of transmitters and more power by having more
nuclear power generators, we could have gotten all
that data back very quickly. That’s an example of these
intelligent compromises that we had to make. Another thing I wanted to talk about, because there’s so many students here who will be involved in, some of them in space exploration, more
of them more generally in aerospace, but whatever
you’re involved in, it took tremendous
commitment from the team of men and women who had
only those four years to design, build, test,
and launch that spacecraft, and realize that that
launch window that we had in January of 2006, which
was three weeks long, was the only launch window
to Pluto for another decade. Had we missed that launch window, we would not have launched
until the middle of this decade. So people were working,
and I’m not exaggerating, people were working 52 weeks a year, nights and weekends, for
four years and two months, to make this happen. And the commitment that this team showed I think is almost unparalleled. And I can’t tell you, as
the principle investigator, the PI I like to say, I
like to say PI often stands for the principle instigator,
how proud I was of this team. Because no matter how many
problems we encountered, they overcame every single one of them. I never heard people
complain, it’s my anniversary, it’s my birthday, it’s this
or that, they just worked. They were on a mission, in
every sense of the word. So this is the spacecraft that we built. This is New Horizons. This is a picture taken of
New Horizons down in Florida, just a few weeks before
we put it up on top of our launch vehicle to
send it on its journey. I like this picture for a lot of reasons. One is there are people
standing all around it. So you can see it’s very small. The whole spacecraft is about the size of a baby grand piano. It only weighs about a thousand pounds with the fuel that’s on board. You can see the dish antenna at the top that we used to
communicate with the Earth, you can see the power generator, the RTG, that I spoke about a few minutes ago, protruding over to the left. And you can see the super
structure of the spacecraft, because all the gold
shiny thermal blankets haven’t been installed yet. So you really get a feeling for what the spacecraft truly looks like when you open the hood. And then this is our launch
vehicle, the Atlas V, built by Lockheed Martin, now built by United Launch Alliance, but this was before ULA existed. This is a very large rocket. Now when I was a little boy, I used to shoot off model rockets. And I used to mow lawns and wash cars, to get money to get better and
better rockets all the time. You can’t imagine how
much fun it was for me to order this baby. (audience laughs) Because we really wanted performance. We built a very small
lightweight spacecraft and we bought the biggest
rocket anybody would sell us. This was the biggest rocket
in the US launch inventory at that time, 12 years ago, and we bought it with
every upgrade in the book, it was so much fun. I’ll take all five solid rocket boosters, the lightweight nose cone, everything. We’ll put a special purpose
third stage on board that nobody had ever done before. We really souped this
baby up, and it’s big. If you go down to Indianapolis sometime, go downtown and find a 25-story building. That’s how big this rocket is. It’s big. And I’m going to show
you a video of the launch in a few minutes. So when you watch this,
it’s hard to appreciate, even on a big screen, this
is a downtown building taking off vertically, okay? You will see the rocket not just launch, it’ll leap off the launch
pad, because we basically launched it empty. This thing is built to launch
school bus size satellites, and we put this little New
Horizons hood ornament on it. And so, it lifts off at two G’s, you’ll see it cross a cloud deck about 10 seconds after launch, it’s two miles high. The downtown building
is now 10,000 feet high. It went supersonic in half a minute. And eight minutes after it left the pad, it was orbiting the Earth
at 18,000 miles an hour to get started. So you’ll have a chance to see this. But I did want to make one other point. How many of you ever built model rockets? Okay, great, actually more
than think Pluto is a planet. Okay, well that’s all right. So when I built model
rockets, I could never get the decal on straight, and
I just want to point out that NASA has figured that technology out. (audience laughs) Went on perfect, this a big decal, you can see the people next to it, that worked perfectly. And I also want to show this picture, which is, this is New
Horizons inside the nose cone of this monster, Atlas V. That’s the nuclear power generator that’s protruding right there. This was the day that we fueled the nuclear power generator
with the plutonium, glowing hot, at a couple thousand degrees. And then it was radioactively hot, and so we wanted to close
the hatch on the rocket so that radiation would
be absorbed by that hatch. And as soon as they fueled it, they said we had time for a few pictures, so they let the senior
people on the project get their pictures, and
as principle investigator, I asked to go last. And in part, that was out of
courtesy to the other people that had worked hard, but also I knew that this would be the
last picture ever taken before the hatch was closed. This is the last time
anybody ever saw this. They literally put the hatch on. And by the way, for any of
you who are superstitious, this was on Friday the
13th of January, 2006. Things seemed to have
worked out just fine. So let’s see the launch of New Horizons, – [Launch Control] Status check. – [Alan] Just six days later.
– [First Engineer] Go Atlas. – [Second Engineer] Go Centaur. – [Launch Control] This
is Atlas launch control at T-minus 10, nine, eight, seven, six, five, four, three, two, one. We have ignition and liftoff
of NASA’s New Horizons spacecraft on a
decade-long voyage to visit the planet Pluto and then beyond. – [Alan] Cleared that cloud deck. – Plus 15 seconds. Everything continues to look good as the Atlas V vehicle climbs away from Florida’s east coast. The five solid rocket strap-on boosters are burning just fine, sending
the New Horizons spacecraft on its way to the very
edge of our solar system. (upbeat music) – [Alan] Shortly, you’ll
have a chance to see the staging event for
the solid rocket motors. Each of those casings
is about 70 feet tall, so much taller than this building. They come off, as you saw,
in two sets, in two waves, so they don’t collide with one another. And then the vehicle
can really accelerate, ’cause it’s much lighter now. Also, it’s already very
high above the upper fringes of the atmosphere. So watch closely, you see
the two panels come off, that’s the nose cone. So now the spacecraft is
exposed to the space environment at the tip of the spear
as it’s accelerating to orbital speed. (upbeat music) – Yeah, then it went behind
that cloud, that’s it. In eight minutes, it was in Earth orbit, we flew halfway around the Earth to the mathematically
calculated injection point to refire the engines to
take us out of Earth orbit and on our way to Jupiter
for a gravity assist. And this spacecraft is so light and this rocket’s so powerful,
that when we launched New Horizons, it became, and still is, the fastest spacecraft ever launched. And I could tell you Mach numbers and kilometers per hour and all that, it won’t mean much. Let me illustrate how fast
this spacecraft was traveling. When I was a little
boy and Apollo missions would launch to the moon, they would launch at 25,000 miles an hour and, as many of you probably know, it took three days to reach the moon. New Horizons did the trip
to the moon in nine hours. (audience gasps) Nine hours. And we continued at that speed across the entirety of our
solar system for a decade, 24/7, 52 weeks a year. Nearly a million miles per day, every day, for nine and a half years. We launched in January of 2006, we got our gravity assist
from Jupiter 13 months later, fastest trip ever to Jupiter, 13 months. The previous spacecraft had
taken six and a half years. And then off, across
what looks like nothing, it’s just on a viewgraph, oh, it’s just a few inches, right? We traveled at a million
miles a day or almost that throughout the entirety of
two Obama administrations. It’s across an ocean of space, the entirety of the solar system, two and a half billion miles from Jupiter, billion with a B, from Jupiter to Pluto, which we intercepted in July of 2015. The fuzzy ring around the solar system is called the Kuiper
belt, where Pluto lives, and where the dwarf planets,
most of them, also live. And I’ll say a little bit more about our exploration of the Kuiper belt, it came after the exploration of Pluto, later in this talk. Now the actual flyby,
many of you might remember seeing pictures from Pluto as they were first coming down and everything. But it was actually a
two-year flight operation. On the way, during that
almost decade-long flight, we spent our time planning
the assault on Pluto, all the software for the
spacecraft, all the plans, all the backup plans,
all the crew training, the ground control crew,
there were about 50 of us, all of that. And the spacecraft was
the first spacecraft to extensively hibernate on the way there. So it took care of
itself for the most part. We’d wake it up for course corrections, for navigating, for tests, but mostly, it was sleeping. And we on the ground were doing the work of all that planning and
training and getting ready for a one-shot flyby of the Pluto system. And there’s no second New
Horizons if we get it wrong. There’s no propulsion that lets
us loop back and try again. This is a one-shot, after
what was essentially a 26-year enterprise
from idea to execution, and in fact, if it went wrong,
that would’ve been that. So we did our utmost to make sure that we were prepared for everything. And it turned out, there
were some twists and turns along the way, but it all worked out well. One of the challenges was
a navigation challenge, which was, in order to conduct
some of the experiments, we had to fly through Pluto’s shadow. That picture that I
showed you at the outset, taken in Pluto’s shadow,
proves that we did all that right, but in order to do that, we had to hit a little window in space that was only 40 by 60
miles, a little rectangle, and that sounds like a barn door, a big barn door, right? It’s probably bigger than this county. But when you’re aiming from
three billion miles away, it’s not a very big target to aim at. And we went right down
the middle of that pike. We actually ended up only
a few miles off target after all that, and that’s a testament to our navigation team and
our mission control team. But we also, in order
to get everything right, to make all the observations worked out, Pluto, because it’s moving through space at thousands of miles per hour, while the spacecraft is flying by it, 32,000 miles an hour,
and all of its satellites are orbiting, each at a different speed. When you work out all the arithmetic, when you do the math, we had to arrive, we calculated, in order
for the spacecraft, with it’s turning capabilities,
navigation capabilities, et cetera, we had to arrive plus and minus 450 seconds of a pre-programmed time after nine and a half years. That works out to plus
and minus nine minutes after nine years. I have to tell you, yesterday I arrived at the Indianapolis Airport
on an unnamed airline that could not get within nine minutes. (audience laughs) Just to get me from Colorado. But New Horizons arrived at Pluto, after nine and a half years,
only 86 seconds off target. And best of all, it was 87 seconds early. So we did all that, and let me tell you a little bit about what we found. This is kind of a family portrait, a true color picture of Pluto, and three of its five moons, Pluto in the lower right,
and then as you move to the upper left, its very large moon, called Charon, which
was discovered in 1978 from the Earth. And Charon, for reference, I said Pluto’s about the size of the
continental United States. Charon’s about the size
of the state of Texas. It’s a little deceptive in this image, because Charon’s actually
closer than Pluto, so it looks like it’s too big to be just the size of Texas, but it is. And then two of the smaller moons. Pluto has four small moons and the two that are shown here are Nix and Hydra. Whoops. This is the binary planet,
Pluto and Charon up close, shown in enhanced color
to bring out more detail. And you can see just from
looking, first of all, this looks like a science
fiction planet, doesn’t it? I mean, you’ve never seen
anything like this, right? First, we’d never been to
a binary planet system. The pair, which has been orbiting together out in the outer solar
system for billions of years, they don’t look anything alike. Pluto is very bright and very colorful, because there are atmospheric processes and climate processes that keep it bright. And Charon is just an icy
satellite, kind of dingy, not as interesting, at
least at first appearance. These are the small satellites. Forget the dots, that’s for
discussion about craters that are identified by those dots. But just to show you, those objects, which are about the size of counties, are made of pure water ice, with a little bit of ammonia
ice mixed in with it. They’re very bright,
they’re nearly as reflective as freshly driven snow. And they’re lumpy,
because they’re too small to draw themselves into spheres. And from using those craters
to determine how old they are, that is because we know the
rate of cratering out there, and if we count the number of craters, we can determine the age of a surface, or at least get a rough
approximation of that. So it turns out, you
know, it’s kind of like the experiment if you were to go outside out of this building when it’s raining with a sheet of paper. The longer you hold the paper out, the more dots are going
to appear from the rain. The older a surface is, the
more craters that are on it. We can tell from counting these craters that these moons are as old as the planet, they’re four billion years old. Very big clue to the
formation of the system. This is the big moon,
Charon, seen up close. It’s a very battered world. Everything you’re seeing
here is made of water ice. That entire surface is made of water ice. Across the equator,
north pole’s at the top, that’s the orange cap on the top, but across the equator, left to right, you see that giant canyon system. That canyon is ten times the
size of the Grand Canyon. It’s ten times deeper, ten times wider, and ten times longer. It’s the biggest canyon
in our solar system. And it was caused by the freezing of all that water ice. If you’ve ever frozen water ice, you know, in your fridge in a glass,
it can crack the glass? That’s exactly what happened
here, but on a vast scale. When the water ice froze,
after the formation, as Charon was cooling
off, the water ice expands by dent of freezing, and the end result is that to relieve
stress, the world cracked all the way along the equator for more than a thousand miles. If you look at the north
pole, it’s pretty unusual. We’ve seen a lot of polar
caps in the solar system, most of them look like
Earth’s polar cap, or Mars’, which you’ve probably seen. They’re bright and snowy and look like it’s just a white polar cap. We’d never seen kind
of a reverse polar cap. This orangey stuff actually
turns out to be the result of gases that escaped
from Pluto’s atmosphere and plated out and condensed
at the coldest places on Charon, at the north and south poles, and then were processed by radiation to turn this ruddy kind of a color. Whoops, too many. I’m not sure if I can back up, because the only other
button is the red button. (audience laughs) So I don’t know if that
will turn off the machine or back it up or go to the first slide. So, let’s try it and see what happens. Oh, it just backs it up. Okay, we’re safe.
(audience laughs) Okay, I know what you’re thinking, the guy supposedly can
get a spacecraft to Pluto, he can’t work this. (audience laughs) But we didn’t practice that beforehand. Okay, so this is an image, I’m going to show you a
number of images of Pluto and talk to you about some of
the things that we learned. In almost every slide
that I’m going to show you for the next half dozen or nine slides, something like that, in the upper right, you’ll see a picture of
the entire globe of Pluto. And this is called a context image. And the little green box,
the inset in the upper right, the green box within the green box, is telling you where we’re looking on the surface of the planet. And so here, what we’ve
done in the computer, is to take literally a hundred images from the horizons, put
them together in a mosaic, and wrapped them in a
computer on a sphere, to simulate what you would see if you were aboard a spacecraft flying a
thousand miles above Pluto. This is what you would see over that. Now, most of you know,
because you’ve seen pictures of Pluto before, it’s the little planet with the big heart, right? That heart is a nitrogen,
molecular nitrogen glacier, with a million square
kilometers of surface area. In other words, it’s the size of Texas and Oklahoma combined,
the heart-shaped region. This is the left ventricle, if you will, the western side of the heart, is that giant, bright surface, which is all made of nitrogen snow. And you can see, it’s
ringed by mountain ranges. We believe, but don’t know for sure, that all of that nitrogen
is sitting in a giant basin caused by a enormous impact
of a Kuiper belt object, probably a hundred miles
across, that hit Pluto very early on and excavated this enormous hole in the ground the size of
Texas and Oklahoma combined, and lifted those mountains,
as a result of shock waves from this titanic collision. Those mountains stretch
higher than the Rockies in my home state of Colorado. Some of them are as high
as almost 20,000 feet tall. So all those mountain
ranges were lifted up due to that collision. And then later, that basin was filled up with this nitrogen snow that
falls from the atmosphere. And we don’t know how deep it is. We can’t confirm this
theory, ’cause we don’t know whether the nitrogen is 50 meters deep or 500 meters deep or 5 kilometers deep. Because we didn’t have the right type of instrumentation, like
ground-penetrating radars on New Horizons, to
really confirm this theory of the giant impact that
created Sputnik Planitia, this giant basin. But there are other
interesting things going on. First of all, when you look at that, that glacier in detail,
and I will show you a picture in just a
second, you will notice what I call a cellular pattern. Now please, this happened to me in Canada. The minute I said the word cellular, people are texting that the Director of the New Horizons mission is talking about life on Pluto. I’m not, I’m talking geological
cells in a glacier, okay? And these are big, they’re individually, that whole area, is the
size of Texas and Oklahoma, so these are like the
size of giant counties. But those cells are caused
by a slow roving boil that’s taking place in the glacier, due to some heat source beneath it, that’s causing it to
overturn again and again. I’ll prove that to you in a few minutes. This is a close-up on that glacier. And on the left, you can
see the northern half of the glacier and various details up against the mountain ranges, including all sorts of
interesting flow patterns in the glacier. On the right, you see terrains
that are way to the south, with little pits in them. Those pits are individually miles long. They’re due to the
sublimation, it’s kind of like an evaporation, of the
ice down by the equator, causing holes that are
miles long and very deep in the glacier. And there are thousands
of them, as you can see, and I’m only showing you a part of it. Here’s something else really fascinating. This is a picture New
Horizons took 15 minutes after closest approach
to Pluto looking back, and you can see how rugged the
terrains are on the surface. Those rugged terrains
immediately taught us that that nitrogen ice can’t
be in a very deep formation most places, because nitrogen ice is a very weak material, we
can make it in a laboratory and it’s about as strong as
garden-variety toothpaste. So try to build a mountain
out of toothpaste. Even in Pluto’s weak gravity field, it oozes away and collapses
under its own weight. So the fact that we see
these giant steep mountains means that the nitrogen must be a frosting on top of some much stronger substrate. The most common building material in the outer solar system is water ice. We saw it all over the surface of Charon, as I spoke to you about a few minutes ago. It turns out we found
bare patches on Pluto where the nitrogen was missing and we see spectroscopically the fingerprint, the spectrum of water ice. So this picture of rough topography immediately told us that Pluto’s crust is made of water ice,
and that the nitrogen and the other exotic snows on the surface are a frosting from the atmosphere. But also in this picture, you
can see Pluto’s atmosphere, these giant haze layers that stretch for thousands of kilometers, and they stretch into the sky half a million feet up, in these concentric banded layers that no one really expected, but which New Horizons revealed. And we still to this day don’t understand the chemistry that
makes these haze layers. In order to understand that,
we’re going to have to go back with more sophisticated instrumentation and a probe that can
dip into the atmosphere and get the composition
of those haze layers. Here’s a really interesting place. You can see the little green box, the little context image. We’re looking right at the juncture between giant Sputnik glacier
and the older dark terrains immediately to the west. And you can see how many craters there are in this very rough terrain. By the way, this scene is about the size of the state of Indiana, so this is not a small place. These terrains we can age date from the number of craters, the same way that I described before. They date back to the earliest
days of our solar system, four billion years ago. And right next to them,
out on the glacier, you don’t see a single crater, not one. You can see those cells,
the convection cells that I spoke about, and
you can see the pits that are caused by the
sublimation process. What’s causing that convection,
what’s the heat source? We don’t understand it. We need to go back, we
need to have much more, we need heat maps, as one
example, thermal mappers, in order to be able to understand. We need that radar that I talked about to find out how deep the ice layers are. But more importantly, this glacier, no matter where we look, a
million square kilometers, we can’t find a single crater. Which means that these
are very young surfaces, geologically born yesterday. This is proof that Pluto, little Pluto, the size of barely
across the United States, a world which we thought
before we explored it should have cooled off and
its geological engine died, like Earth’s moon, billions of years ago. But somehow, Pluto didn’t
read the textbooks. Pluto’s just happily making
new terrains all the time. This is the size of Texas. And it age dates to be born
yesterday, geologically, only millions of years old, at the most. And here’s a complicated
plot, called the log-log plot, but as we go around Pluto and
look at different terrains, we find the very old
ones like I spoke about, we find the very young
ones, but we also find middle-aged terrains,
which shows that Pluto has been active, making
new types of geology all throughout its history. We’re not just happening to live at a time that we sent New Horizons
when Pluto was suddenly having a spasm of activity. These plots show us from these age dating of different places on
Pluto, that different units were made at different
times, all through the last four billion years. So somehow, and the geophysicists
don’t understand it, Pluto is generating new
terrains and has been doing this over the entire history
of the solar system, something that was thought impossible for a world this small,
that it should have died, geologically, very long ago. Here’s another one
which we didn’t predict. So this is a map that’s
color coded by altitude. The highest altitudes
are in yellow and red. These are the mountains around the glacier that I spoke to you about that
are up to 20,000 feet tall. And then down, the lowest terrains, down in the glacier,
that’s the purple stuff. But what I want you to focus your eye on are those red arrows and
that pool of material that’s come out of a chute, that actually came down that chute where you
can see in the lower right, a flow pattern, and pooled out in an area about 50 miles across, a giant
avalanche of titanic scale. If this happened in the
Himalayas, it would be world news everywhere. Somehow on Pluto, giant
avalanches are taking place, and look at that surface,
there’s not a crater on it. This is taking place today on Pluto. And then we found ice volcanoes the size of Mauna Loa in
Hawaii, this is one of them. We have all kinds of
evidence for ice volcanoes and cryovolcanism, as
its called, all across the surface of Pluto. This edifice with the hole in the middle, that you see there, is
about 100 miles across and the hole in the
middle is 15 miles deep. It’s incredible. And it has, and again, notice
on the flanks, no craters. This was either recently
active or recently constructed, but either way, somehow Pluto has created these ice volcanoes or kept them running for billions of years. And this isn’t the only one. We have three of these and
then a whole ‘nother type of volcanic province on
another part of Pluto that shows another way that
Pluto is somehow active, which we don’t understand
and we will never understand unless we send another mission back with more detailed imaging and better compositional spectroscopy
and these thermal sensors that can tell us if the volcanoes are actually active today, et cetera. And then who ordered this? A frozen lake on Pluto’s surface, sitting in a hanging
valley, which we know, because we have stereo images that show this is in a valley in mountain ranges to the west of the glacier. And this, you can see
the shoreline around it, there’s no craters on it,
it’s about 20 miles long, it’s made of the same stuff, the nitrogen. But the thing is, you
can’t have liquid nitrogen on Pluto today, because the atmosphere has too low a pressure. For those of you who
are technically trained, in other words, the
current surface of Pluto can’t reach the triple point
where liquid can be stable. But here’s forensic evidence, right? If you watch CSI, right, there’s that one clue every episode. This is the same deal,
this is a forensic clue that Pluto used to have a
much thicker atmosphere. In fact, when you work
it out, it had to be 10 times higher pressure than
Mars’ atmosphere is today. Why did Pluto have higher pressure? For how long did that persist? How did those giant craters
that were formed by impacts make it through that thicker atmosphere? How does this all add up? We don’t know. We had one little flyby
through the system. We got a first glimpse of
this very complicated world, this world that’s every bit as complicated as the Earth or Mars. And we have very strong
circumstantial evidence that beneath the glacier is
a global liquid water ocean. That’s right, below
those ices, the surface, which is 400 degrees
below zero Fahrenheit, as you go deeper and deeper
and the weight of the ice increases and increases
and the temperature goes up as a result, because the
higher pressure corresponds through the perfect gas
equation to higher temperature, we get to a place where that water ice that makes up the entire
crust of Pluto liquefies and there’s a global ocean, maybe with fish inside or whales, Plutonian whales. Or maybe with nothing inside,
maybe it’s just water. But any way you look at it, the fact that Pluto could have an
ocean, and to the right, in the upper right, is an
illustration I didn’t make, but I really like. There’s the Earth on the
left, and the blue bubble is a sphere that’s equal to the volume of all the oceans of the Earth. And then to its right is
Pluto, the round, ruddy disc. And then to the side of it, the blue dot is the calculated estimated
size of Pluto’s ocean, which is almost the size of Earth’s ocean. Who would’ve thought, who
would’ve thought that? If I would have suggested that before the flyby of Pluto, I would have been laughed out of the room. And yet, Pluto has all of that, and if we’re lucky, this video’s started, we’re going to now fly
over the surface of Pluto as if we were in an airplane, using images from the horizons, From the north pole down onto the glacier. Now we’re going to take
a thousand-mile flight in about 60 seconds, starting
off in those polar terrains, where you can look inside the craters and see layering and all sorts
of other interesting detail, then you see these tracks,
we believe these tracks are due to dust devils or tornadoes that went across the
surface, and then we come up onto badlands and eventually
onto mountain ranges. There’s a scale bar on the side in blue, it says six miles, just for the scale bar, so you can see how big these
chunks of water ice are that are covered in nitrogen snow. And then off into the glacier, where you see hundreds of
dunes in vast dune fields, hundreds of miles long,
as we fly to the south towards the equator,
across Sputnik glacier, all the way down into
the equatorial regions. This is like the best
science fiction world. I mean in many ways, I like
to say that the solar system saved the best for last. Pluto has totally stunned us. And this project, with
all of its ups and downs and near misses and political intrigues and design problems and test problems and all kinds of things, is chronicled in a lot more detail than
I could give you here in a book that my co-author
David Grinspoon and I wrote, called “Chasing New Horizons.” I call this book my hundred lost weekends, because it took me two
years to get this written and ready for publication. And this is an unabashed sales job. If you want to read more about
New Horizons, buy the book. It’s now out in paperback,
so it’s not expensive. You can order it on Amazon
or in your local bookstore. After the flyby of Pluto and a year to get all the data back, we went on out into the Kuiper belt
and flew by this object on January 1st, New Year’s
Day, of this year, 2019. This object has a license plate name that we found with the
Hubble, called 2014 MU69, which is not very easy to remember. But we gave it a nickname
called Ultima Thule, which is a Latin phrase
for beyond the known world, which really, literally, this object is. Have you ever seen anything like this, even in a sci-fi show,
even in “The Expanse?” No. On “Star Trek?” No, no, nothing like
this has ever been seen. This is a primordial, meaning
ancient, building block of planets like Pluto. It’s only about 25 miles
long, so it’s tiny. I thought I had, and
maybe this is it, yes, this is the video. There’s Pluto, zoom up on Pluto, and little Ultima Thule
appears right there. Look how little it is, it’s like we flew another billion
miles to rendezvous with one mountain block on Pluto, right? And we did that at 32,000 miles an hour, in the darkness of the Kuiper belt where it’s darker than this room, right? So we had to hunt this
thing down in the dark and fly by it at 32,000 miles an hour and get all the calculations right in order to produce images of it. And it’s just this wild wooly beast that doesn’t look like anything
you’ve ever seen before. It’s called a contact
binary, it’s two small worlds that came together and
they’re joined at that neck, that bright ring in between them. And you can see, because
these are images made as we flew by at some different angles, that it’s also very highly flattened, almost like rocks that
you would skip on a pond. How did the solar system do that? We had no idea that things
like this could form, particularly on this vast
scale, the size of counties, and that they could gently merge, there’s no signs of violence. Somehow, they gently came
together and almost docked. In fact, when we wrote the paper, with 200 of my best friends as co-authors, and submitted it to science,
I used the word docked and one of the referee’s
comments back was, you will not use the word
docked, that is done by ships piloted by human beings, and docking is a result of intelligence,
find another word. So we use the word merger now. But they docked. (audience laughs) Okay, there. All right, so this has really
been a tremendous mission of exploration, and I have
a few candid pictures, beginning with this one, to show you, of what it’s like to be a part of this. Not at the beginning,
when you’re designing and building, but at the culmination. For people who worked 15
years, from 2001 to 2015. This is a live shot, taken from our science operations room
at the moment of the first image being put on the big screen from the Pluto flyby,
the first high-res image. And you can see, these are
all scientists on my team. And you can see the
excitement in this room. And every one of these people was like, “Is this going to work or not?” Right, ’cause we’ve
got this remote control spacecraft three billion miles away, doing its thing, with no second chance. And I just love this
picture, because you can feel the energy in it. And then, three and a half years later, when we got to Ultima Thule, when we did that flyby on New Year’s Eve and New Year’s Day, here’s
the scene in the room, right? Do you think that they were excited when the first image came down? You can just feel it. That’s what real science and
real engineering is about and real discovery, right? Is it’s actually not just
cold and calculating, it’s actually very emotional. And it is, teamwork like this, is just like teamwork on an NFL team that wins the Super Bowl. This is the Super Bowl of
solar system exploration, in all of history so far. Here’s another picture from our team. These are people that worked on this for three and a half years to
make this flyby turn out. And you can see that they’re
pretty happy about it. That didn’t last long before
we went back to nerding out at the computer, and
the end result of that is, we made the cover of
the Rolling Stone for geeks, Science Magazine. This is a publication from this May, about three or four
months after the flyby, when we took the cover of Science with this beautiful color
image of Ultima Thule. So, I’m going to wrap up
this talk a little bit. But first, I want to talk about what this exploration
meant beyond its science. Did any of you see this bumper sticker? Or do you have Pluto shirts
or any of the paraphernalia that is now sold everywhere
on the web, yeah, with hearts on it, you know. This kind of stuff, something
really magical happened. You know, when I was growing up, and then when I was going to grad school, first missions to new
planets were happening every few years. I don’t remember the
first mission to Venus, I was too young, the
first mission to Mars, I was too young. But I do remember the
first missions to Mercury and Jupiter and then
Saturn, Uranus, and Neptune in the 80s. And every time that happened, it was like a worldwide news event. And the same thing happened,
but it hadn’t happened for a generation. From 1989, when Voyager
finished at Neptune, to 2015, 26 years, nothing like this had ever happened. And a lot of people,
a lot of jaded people, particularly in Washington, D.C. said, “Ah, they’ve seen it
all, no one will care.” That’s not what happened. Thousands of people came
to our mission control to be there at the flyby. And you can see them. Look in the back, you see the screen, you see the zero zero four? Four seconds to closest approach, they’re going crazy. And it was all over the news. We were on the cover of
560-something newspapers above the fold the next morning. Our website took two
billion visits in 48 hours. Yes, half of them were my mother. (audience laughs) But only half, she’s only so fast. Google gave us the Google Doodle, that’s little New Horizons going by Pluto. We were on the cover of so many magazines that we lost count. In fact, this is a true
story, my next door neighbor called me a week before the flyby. And he’s a small business
owner, and he said, “Alan, we take seven
magazines at our house.” “Six of them have come so far this month. “You or your mission are on the cover “of every single one.” He said, “The last
magazine is Cosmopolitan, “and if you are on the cover of that, “I’m jumping off my roof.” (audience laughs) So we saved his life, we
weren’t on the cover of Cosmo. But NASA hadn’t seen anything like the web and public response to this
exploration since Apollo. And that’s their term, not my own. It shows that people in the 21st century love exploration as much as people in the 60s and the 80s did. This is a superhuman, I
mean, no other species even looks at the sky and
knows that they are seeing other worlds in space, and
somehow we, our species, has figured out how to
go explore the universe. And for those of us who
have been on New Horizons all this time, working behind the scenes, nights and weekends, for 15 years, to design and build this
one little spacecraft to send out on this risky
journey, all by itself, across the entirety of our solar system, to the very frontier, and then
pull off this exploration, is an unbelievable feeling. And to this day, now four
years after the flyby of Pluto, I get emails, sometimes I run
into people in the airport, or some airport, and I
don’t even know them, and they say, “You know,
I worked on New Horizons, “I worked on the rocket,
I worked on the RTG, “the nuclear power supply,
I was at Ohio State “University when you were
testing the antennas, “I was on this, I was on that, “and I just want to say thank
you, I’ve never been a part “of any project like
this in my entire life.” And nothing, even all the
science that we’ve done, makes me feel better than to know that this was so meaningful
to people that worked on it and so meaningful to
the people of the world, all around the world, not
just in the United States. And that we, NASA, put all
this data on the web, available to anyone in any country,
can log in and download images and spectra and everything else and work on this, you know. We don’t just do it for
people in the United States, we do it for the world. It’s an amazing feeling for all of us who got to be a part of this project. I’m going to close by talking
about what if we return. There are a lot of mysteries to Pluto. We did not expect it
to be this complicated. No one could have expected
it to be as hard as Mars, and to be as active as any active world in the solar system. We don’t understand the glaciers, we don’t understand the ocean, we don’t understand the atmosphere, we don’t understand what
generates the geology, we don’t know what’s
making the avalanches, we don’t understand the satellite system, none of it, because we
just went by in a flash. And now we know that if we go back, we want to be in orbit, we want
to map the rest of the planet, we want to map what we’ve
already seen in higher detail. We want to bring other
kinds of instrumentation, like I spoke about, radars to look down through the depths of the ice and find out how far down it is.
Thermal mappers to see if we can find hotspots,
like at those volcanoes, see if they’re currently active. We want to put a mass
spectrometer in the atmosphere and measure what those hazes are made of. We want to do all that
and more, and to do that requires an orbiter, so my company, the Southwest Research Institute, a very large nonprofit
with 3,000 employees, 450 in the Space Division where I work, just completed a half-million dollar study of how to do a Pluto mission. And this is one slide from some of the orbital mechanics that we did. And we designed an entire orbital tour of how you would go about this. And it turns out, it’s very cool, you can use the big moon, Charon, to make close flybys and
use them as gravity assists, to tour, to motorboat, all
around the Pluto system. With every orbit, you make
a close flyby of Charon, and Charon redirects the spacecraft, to dip down into the atmosphere,
to visit other moons, to go over different parts of Pluto. And over a two-year period, we showed, and this looks complicated
when you show all the orbits, but you can tour the entire
thing with one vehicle. And then, this is even
bigger breakthrough, we found that Charon is powerful enough, that when you’re done at Pluto, when you’ve mapped it
all, when you’ve put all those new experiments in the atmosphere, when you’ve done all those other things and got those datasets back,
Charon is powerful enough, with two more close flybys,
to actually take you back out of orbit, to go
on into the Kuiper belt and explore other Kuiper belt objects like Ultima Thule and
dwarf planets like Pluto. So with one mission, which can make, and these dips are the closest approaches to different satellites
that are color coded there, we can do all the Pluto
system, and then we can go on into the Kuiper belt and
be the next generation of Kuiper belt explorer, too. We used to think that would take at least two different spacecraft
and two different rockets, and now we know we can do it all with one. And that’s going to be a big cost saver. And hopefully, we’ll
get a chance to do that. It probably won’t be
me, it’ll be some of you that’ll have the chance to do that. And so I’m going to
close with this beautiful true color picture of this beautiful little sci-fi planet on the
edge of our solar system, the first dwarf planet in the Kuiper belt ever explored, with a salute
to the New Horizons team. And I thank you for coming tonight and then I’m going to take your questions. So thank you very much. (audience applauds) And we have a bit of an
ice breaker and a bribe, so there are two microphones. And Steven has these cool bumper stickers. Hand me one of them. I think they’re the coolest bumper sticker in the space business. It says, “My other
vehicle explored Pluto.” (audience laughs) Right, right, I mean
somebody’s got, you know, “My other vehicle is a
truck,” this is better. In any case, we have four of them, so the first four people
to ask questions get, here, five, get bumper stickers. Yes. – [Man] Nice to be right close there. – There you go, good thinking. – [Man] So my question is
with the decreasing cost of rockets these days, there’s such great rocket science going on,
and the price of getting to space is so much cheaper, it would seem that it would be cheaper to send out now a lot of planetary explorers
with little bit heavier, but a lot cheaper components,
and do you think one, will that bring us back
to the age of Mariners and Voyagers, where we
can send five or six up and just hit a bunch of Jupiter’s moons, and also, once we get to
that stage, what would be the limiting factor,
would it be manufacturing or cost of rockets, or would it be just the bandwidth or the rocket scientists and people to interpret
the data, what would be those limiting factors? – Yeah, so if we took
advantage of reusable rockets like SpaceX is building
and now others as well, we could more or less eliminate
the cost of the launch, could we afford more spacecraft
for the same budgets, and I think absolutely. It turns out the rockets
are typically about 20 or 30% of the cost, so you
couldn’t get a factor of two, you couldn’t fly two for every one, but it would certainly help. But we’re also now in a revolution where we’re building a lot smaller and less expensive satellites. And so I know for the close exploration, like of the moon and
Mars and the asteroids, that we’re now able to get to much cheaper planetary exploration
missions that we can send out in much bigger numbers,
just like you asked about. – [Man] And are there economies of scale when you can say, hey,
let’s build three or four of this, or is it pretty much one person screwing in one component, planning out every last thing, or is– – I’m happy to answer that question, but let me just point out
that asking a second question does not mean a second bumper sticker. (audience laughs) Those are for other people,
we’re going to take turns. Yeah, absolutely, if we could do more, we would get an economy of scale, and so the second New Horizons and a third would each come down the cost curve, particularly if you can build
them in rapid succession to the same design before
parts go obsolete, for example. Okay, yes sir. Okay, Steven’s going to help you there. – [Boy] How come the image
of Pluto was so blurry from Hubble, although Hubble
can take such good shots of like Andromeda and the Sombrero Galaxy? – That’s a stupendous question, that is a spectacular question. So, how come Pluto, only
three billion miles away, looks blurry, but galaxies
that are much farther away look so great? It’s because those galaxies
are really enormous structures. And so even though our actual
resolution on the galaxy is much worse than Pluto,
we can put a lot more pixels on them, and therefore
see a lot more detail. That’s a great question. Enjoy the bumper sticker. Back over here. – [Man] Yeah, so we learned
a lot of very interesting, very cool things from
our first visit to Pluto. So my question is what
bodies or moons or anything are you excited to
visit for the first time in the near future? – Personally, I get to
pick, I get to be king. Okay, Earth’s great, we need
to study the Earth more. But actually, this whole
collection of dwarf planets turns out to be very heterogeneous. They have different colors
and different compositions and different densities. So some are made of ice
and some are made of rock, for example. They have different numbers of satellites. They’re every bit as
diverse as, for example, the four terrestrial planets. And we’ve only been to one
of them, Pluto, so far. And it already taught us
a tremendous amount of, rewriting textbooks, so I think missions to these dwarf planets are in order. But we also have a lot
to learn closer to home, to do more detailed missions. NASA just selected a
mission called Dragonfly, which you might have heard of. It’s actually going to land
a nuclear-powered drone that can fly across the surface
of one of Saturn’s moons, which has rivers of hydrocarbon and lakes that could
contain prebiotic chemistry, and that’s just one example. So the future is very bright
for planetary exploration. And then on top of that, we’re
going to send people to Mars. That’s going to happen,
and it’s going to happen by the 2030s. I know that, because even if this country can’t stick to it politically, I’m a Tesla owner and I’m
pretty sure Elon will. (audience laughs) Next question. – [Woman] Hi, I remember when
New Horizons got to Pluto in 2015, and I came into work that day, and I was like, “Great, Pluto.” And all my coworkers are like, “Okay.” But I don’t know, it was really cool, that was such a great
feeling and I remember that was something that inspired me in my college career. Something that you were teasing at, was you did the flyby behind the planet and you were looking at the atmosphere. Can you talk more about that? – Yeah, absolutely, sure, sure. That’s a great nerdy question,
I’m always up for that. So the idea is, is that we
could probe Pluto’s atmosphere by looking at the way the
sunlight filters through it. And it’s not just taking pictures of it, although that did show us
things like the haze lighters. Our ultraviolet spectrometer
is able to watch the way the sunlight is extinguished
as a function of wavelength and determine the composition
as a function of altitude. And it can only be done when you backlight the atmosphere as a probe through it, and the brightest thing,
brighter than any of the stars, is the sun. So we aimed to go across Pluto’s shadow in order to put the sun
filtering through the atmosphere and look at it with that
ultraviolet spectrometer. – [Woman] What did you find
out about the atmosphere by doing that? – So, we found out a lot of things, which mostly you need
graphs, because they’re about hydrocarbon chemistry
and the rate at which the nitrogen falls off with
altitude and the escape rate. So we found out, very top
level, about the composition, the thermal structure of the atmosphere, the escape rate of the atmosphere, that turned out to be
a thousand times lower than had been predicted
by Earth-based models, and we learned about the haze layers that we really didn’t expect, all of that. – [Woman] Thank you. – Thank you, yes. – [Man] So Pluto has
a very eccentric orbit and I was just wondering what you thought would be different about
a long-term mission orbiting Pluto versus a flyby mission, compared to some other such
missions of other planets in the solar system? – Well, you know, one of the big lessons of planetary exploration has been that we do flybys first, we
get the lay of the land, and then if it’s high enough priority, we go back with more detailed missions, first orbiters and then landers. And every time we’ve done that, it’s been very successful, in terms
of teaching us a lot more. In the case of the Pluto flyby, we flew by but we could only see
one side of the planet, because we went by so quickly. And we really haven’t mapped
the rest of the planet. We also couldn’t carry all that kind of new instrumentation that I talked about, because in order for New
Horizons to be light and fast, it wasn’t able to carry
more than the seven scientific instruments that we had. And, because we were
only there on one Tuesday in all of human history, we didn’t have a chance
to see things changing, and yet we know this is a dynamic world, where, from avalanches
to atmospheric phenomena, it’s changing before our very eyes. And so if we can go there with an orbiter, can stay for years and watch the way that it’s changing, combined
with the new datasets from different types of instrumentation, and the ability to map
all of the rest of it that we couldn’t see, and get up close to all of its satellites
that we couldn’t get to, we would learn a lot more. Thank you, yes. – [Man] Do you expect to
see migration of tholins back and forth between
Pluto and then Charon, and then Charon back to Pluto again, if we send a mission there? Have you observed migration
of those hydrocarbons back from Charon back to Pluto’s surface? – Yeah, so let me translate the question just a little bit for those who don’t know as much as this gentleman does. The material on the
surface of the moon Charon that I showed you, that’s
the ruddy red stuff that makes that polar cap, carries the Latin name tholin, which is just a fancy word
for hydrocarbon gunk, okay? And this is the gases that came off Pluto that I spoke about that have plated out at the north pole, where the temperature is literally 15 or 20
degrees above absolute zero, so those molecules are
stuck on the surface, ’cause it’s so cold. And then the solar ultraviolet sunlight makes chemistry happen that creates this hydrocarbon gunk called tholins. And his question is, could the tholins also be going back to Pluto. And the answer is absolutely not. And the reason is that
we can make those tholins in a laboratory and we understand many of their physical
and chemical properties. We’ve been making these things for decades in a laboratory. They’ve been seen in other places around the solar system, too. And they’re very stable
molecules that can’t evaporate, because they’re very heavy,
long-chain hydrocarbons. So at the temperatures on Pluto’s surface, they can’t get back up and
transit in the other direction, they just keep building
up and building up. That’s a great question, thank you. Yeah. – [Man] So, earlier in
the talk, you spoke about some of the instruments
you would want to see on a new mission, such as thermal sensing, a ground-penetrating radar. Do you know other types of instruments that you would want on
a new mission to Pluto? – Yeah, absolutely. So I mentioned a mass
spectrometer as another example. I mentioned thermal
mappers as another example. Those are the four that I mentioned, ’cause they’re at the top
of my Christmas wish list. But there are lots of other instruments that we would also like to see. For example, until the 2060s, Pluto’s southern hemisphere
is in polar darkness, the same way that Antarctica
goes into darkness for months every year. But Pluto’s year is 250 years long. So it’s polar darkness lasts decades. So if we send the
mission there in the 30s, it’s still going to be dark. So we want to send very
low light level cameras and spectrometers that
New Horizons didn’t have, so we can even map those
polar dark terrains, so we can get a map of everything. And that’s an example. Another example is, we
want to do what are called gravity investigations, that aren’t really measuring gravity, but
they’re using gravity to measure the distribution
of mass from place to place. So we can determine the
density of the mountains versus the valleys, we can determine exactly how much material is
in Sputnik Planitia glacier, we can measure all those things, and much more about the subsurface, and get the structure of the interior of the planet, as well. And there’s another
long list of other kinds of atmospheric instruments,
there’s going to be a big shootout. There are going to be 20 or 30 ideas for scientific instruments
that’ll compete, and the top 12 or so will
get selected for the mission. Okay, thanks. Yeah. – [Man] So most of the
nitrogen that was observed is the beta phase
nitrogen, and I know that there was some talk about
improving the detection between alpha and beta
with the incorporation of carbon monoxide and methane might make it more observable. Have you guys observed any alpha nitrogen or has it all just been the beta phase? – I love it when you talk dirty. (audience laughs) Down and dirty geek speak. So in order to separate these different molecular forms, these
different phases of nitrogen, and the other molecules
that you talked about, you need spectrometers that
have higher resolution, not being closer but
higher spectral resolution, so more light-gathering
power than anything we could afford to fly on New Horizons, from a math standpoint. And those instruments exist on the Earth. And we put them at the back end of the largest telescopes on the Earth, and we can see alpha and beta nitrogen in Sputnik Planitia from the Earth. Now what you can’t get from the Earth is the high resolution to
map from place to place at high detail. So what we need to do is go back with much bigger
telescopes on that orbiter. Our biggest telescope
is only this wide, okay, it’s like a little home-built,
except it’s very high tech, but it’s only this wide. We want to go back with
meteor-class telescopes, that gather a lot more
light, that can actually collect enough signal to have these higher spectral resolution spectrometers to do exactly what you’re talking about. – [Man] It’s just
interesting ’cause of the vast viscosity difference, but thanks. – Yeah, okay over here. Left, right, left, right. – [Man] Thank you, so you had noted that on New Horizons, all of
the systems were redundant and they had a copy of each other. So during New Horizons’ flight, did any of those systems
fail and during the flight, was there ever a point where you all had to start mentally
preparing yourself, you know, this one might not actually work? – Okay, great questions,
two questions, two answers. So it turns out, here we are
four years after the flyby and everything’s working. It was working at flyby, it’s working now. All the prime systems and
all the backup systems. Now on the day of launch,
the very first day we were out of the box in space, we did have one system go red on us. And it started working about
three days after launch and has worked for almost
14 years ever since, never had a problem. So the spacecraft is super
healthy and we expect it to be able to operate
for 20 more years. Then you also asked if we ever had a case where we might be worried about whether we would make it. And we actually did. And some of you might know the story, but after flying 3,350
days or 50-something days, to reach Pluto, 10 days before we arrived, on July the 4th, 2015, which is a day known for fireworks, right, my cell phone rang, it
was the project manager calling, saying we’ve lost
contact with the spacecraft. Which is never supposed to happen in any space flight. And in fact, “Chasing New Horizons” opens with that story, that phone call, people pouring in on the 4th of July in sandals and shorts and Hawaiian shirts, to mission control to
try to fix the problem, and obviously, because
you’ve seen my talk, we worked it out. But it was a very near death experience for the spacecraft, and it was caused by a human error that we did to ourselves, a very subtle programming error. But we fixed it. Yes. – [Man] Yeah, so you talked a lot about how Pluto is still a dynamic planet and may still have a lot going on on it? – Yeah. – [Man] What do you think it says about the formation of the solar system and the processes going in it right now that there is such a dynamic planet so far away from the sun and do you think there is other bodies similar to Pluto we can find around the Kuiper belt? – Yeah, so let me answer
your second question first, is that we know that the dwarf planets include some that look like
very close cousins of Pluto, from what we can tell, okay? So definitely a yes to
your second question. What about the formation
of the solar system, what is this telling us? That’s a much harder question to answer and I don’t think
anybody knows the answer. But more than telling
us about the formation of worlds like Pluto,
it’s probably telling us that our understanding of the geophysics and the geological
engines that run planets is missing some physics,
maybe some chemistry, too, because we were not expecting
the level of complexity that the geology has resulted in or the level of activity after so long. And to this day, this is four years later, there’s no accepted
theory, there’s some ideas, but no accepted theory for
why Pluto is so active. It’s really a mystery,
which is the best stuff in science, right, ’cause
we found out something new that we don’t get yet. We’ll see. Okay, yes. – [Man] Would you talk a little bit about the complications and the complexities of communicating with a
satellite at that distance traveling that fast and sort of the power of the transmitter you’re working with? – Yeah, sure. – [Man] And getting data back? – Yeah, so Pluto’s three
billion miles away, the spacecraft’s three billion miles away. Radio waves travel at the speed of light. So when you work out the math, if we want to send
instructions to the spacecraft, we launch that as a set of radio commands from the Earth and it takes,
currently, where we are now, up in the Kuiper belt, it
takes six hours to get there. And then when the spacecraft perceives it and says, “I got it,” and sends you back checksums or whatever,
it takes six more hours just to find out you got
it, so the round trip is 12 hours. So it’s like playing chess,
one move every 12 hours, right? And when problems come up,
it makes it a lot harder to fix them, because every
move requires a half a day before you can get confirmation it worked. Now you also asked about
transmitting data back. So the way that we do this is that we have a small transmitter and a small
antenna on the spacecraft. You saw the size of it, it’s only about six feet across, the dish. And the transmitter is only 30 watts, 30 watts, not like an AM radio station’s 30 kilowatts, 30 watts. And that signal spreads out over four billion miles of space, it is incredibly weak when
it gets back to the Earth. So we have receiver antennas in locations around the Earth, called
the NASA Deep Space Network, that are the size of football fields. And their receivers are
cooled by liquid helium to almost absolute zero to
eliminate thermal noise. And we can pick up the
signal of New Horizons and send those pictures and
spectra and other things back and receive them and make
all the beautiful imagery that I just showed you. But at the expense that
we have to send them at a relatively low data rate,
compared to your cell phone. We’re all frustrated
when you can’t download a hundred megabit video
in 10 seconds flat, right? New Horizons is sending
data back to the Earth at about a thousand bits per second. So a single image will take an hour or two to get to the Earth. It’ll travel for many hours en route, but to build that image up
at a thousand bits per second is pixel by pixel, pixel by pixel, it’s like watching the grass grow. But think about it, it’s
a 30 watt transmitter billions of miles away. That’s why it took us a year
to get all the data back is we had a whole flash
drive, gigabits worth of stuff to send back at this slow rate. But it’s amazing that we
can do it at all, I think, I mean, from those kind of distances, it’s just incredible to
think about, thank you. Yeah. – [Man] Are there any sensors
that you really wanted to include on New Horizons that you were unable to include or are
there any that, in hindsight, you wish you had included but
didn’t think to at the time? – Yeah, great question, of course. All the things that we
now know will tell us what to put on the orbiter, right? But all those carcasses that I showed you in an early slide, the missions that never got off the drawing board? They didn’t get launched because mostly they were too ambitious and
they got out of control, they cost too much and
NASA couldn’t afford it, and they’d get canceled,
then we’d have to start over. The great success of
New Horizons is because we actually practiced appetite control. We actually said what’s the
minimum set of instrumentation to get the basic scientific objectives of a first flyby done. And by not trying to add
ornaments to the tree and then sink under our
own weight, if you will, metaphorically, we actually got the exploration of Pluto done. So I wouldn’t change a thing, because we actually go it done. I would send an orbiter next. – [Steven] I will just say, the people at the microphone now, we
have time for these questions. – Okay, we have time for
these five questions. Yes, ma’am. – [Woman] Here’s your PR question. – PR. – [Woman] Yes. – Okay. – [Woman] So in regards
to, you said there was a generational aspect to
it, did you do anything differently, was it just
luck, and when we are in the workforce, next in this generation, what do we do with Mars? – Well, I don’t quite know how to answer your second question, but I’ll
answer your first question. Is that we did do things differently than had been done in the old days. I mean, we put everything out on the web, so it was instantly available. And we were on Twitter
and we were on Facebook and we were on Insta. And we were doing all
of that, so that we were involving people, and they
could be a part of it. You know, back in the earliest days, like first missions to everywhere else, even to Neptune in the late 80s, you had to be in the room
at the Jet Propulsion Lab to feel like you were a part of it. You could read about it in the newspaper the next morning, but you couldn’t be sharing in real time,
like as a human event. And I think by taking advantage of the modern technology,
we really made a difference. Okay, yeah. – [Woman] Okay, so coming
from a biological perspective, you mentioned a river
with prebiotic chemistry. You also mentioned water inside Pluto. So coming from that perspective, what are some things
that NASA or any other space program wants to
explore biologically in Pluto or in other
planets, and what measures are they taking right now to explore that? – Okay, that’s a bunch of questions. So first of all, I want to clarify that the hydrocarbon
river that you mentioned that I had mentioned
earlier is not on Pluto. That’s on another place,
a planet-sized world, a satellite of Saturn called Titan, okay? So that’s not Pluto. Those things might exist on Pluto, but we didn’t discover them, okay. But one of the highest priorities in all of planetary science is to find out if there’s life that’s evolved, or even prebiotic
chemistry, in other locales around the solar system. And one of the other biggest discoveries in my lifetime, in my
career, besides the fact that the solar system is
teeming with dwarf planets, and the dwarf planets
outnumber all the other types 10 to one, is that we used to think that the Earth was completely unique. When we would look out
with our telescopes, we couldn’t find another
world that had oceans. Well, we were completely wrong. It turns out there are lots of oceans all around the solar system. They’re just on the inside, instead of sitting on the surface. And they’re very common all across the middle and outer solar system. And the fact that these oceans exist, oceans of liquid water, at
reasonable temperatures, where life could evolve,
is a complete game changer. And we have a whole series of missions and something called an
Ocean Worlds Initiative to go study these. The first big mission in that initiative is called Europa Clipper, and it’s going to a planet-sized satellite of Jupiter, called
Europa, that not only has an ocean on the inside, but
geysers in which the ocean actually sprays out into
space and we can sample it. And that mission’s going
to launch in 2025 or 2026. Thank you, yes. – [Man] Triton, from my understanding, is very similar to Pluto and I assume is easier to get to than some
place in the Kuiper belts. Why not go there next
instead of going back to the Kuiper belts and
what’s next for New Horizons after Ultima Thule? – Okay, two very different questions. So first of all, for those who don’t know, Triton is a moon of Neptune
that used to be a planet on its own orbiting out
there and got captured into orbit as a satellite of Neptune. And Voyager visited Triton, and so we know a lot about it. And it is a cousin of Pluto. It’s not as geologically active. We would very much like
to see a future mission to go back to Neptune and to study Triton and many other phenomenology there. I can tell you just today, NASA announced a whole series of studies for new missions in the solar system. One of the missions that got funded, and I’m on this team, is a Pluto orbiter. That’s as of today. I think I had 54 emails about this, people were excited. (audience applauds)
Thank you. And the woman scientist who runs that is named Carly Howett. And then another mission was selected among these 10 studies to go
back to Neptune and Triton. And a woman named Abigail, or Abby Roemer is in charge of that one. So we are working on
getting those missions. Thank you. Next to last. – [Woman] So you
mentioned the small window you had to get behind Pluto
without hitting anything and everything going, as well. So were those calculations
done before you left off, or was those one of the ones that you did while New Horizons was on its way there and what kind of stuff did you do while it was on its way there? – Yeah, so those calculations were done before we ever launched. They were part of the design process. We had to know how accurately
we’d have to navigate so we’d know what kind of
navigation sensors to buy, and we had to know what
kind of computations we had to do in real
time on the spacecraft and how much fuel to have on board so that we could home
in to the right timing and everything else. So all that kind of stuff
has to get worked out far in advance, even before you can construct the spacecraft. And that’s one of the
things I really liked about the whole enterprise of what we do, is that you have to think really hard and have all these different
technical specialties, different types of
engineers and scientists to get all this right,
because once you send it out, there’s no getting it back to change it and prove it, oops, I forgot about that. What was your second question? – [Woman] So like, what did you do while– – Oh, on the way? – [Woman] Mm-hmm. – Yeah, it was over 10 years, right? And people asked me, and all my colleagues on New Horizons, we would
get asked all the time, like, “Are you bored?” Like, “What do you even do, do you work “on New Horizons, I hear the
spacecraft’s hibernating.” Right, and we were like
working a million miles an hour every week of the year for nine years. For comparison, I told this
in a class this morning to some students, when Voyager flew across the solar system,
their team was 450 people. Our team was less than 50 people. So some of that’s modern technology. We have laptops, they didn’t. But we were just very busy. We had the work of a
450-person team to do, and so literally, the entire journey across the solar system. Alice Bowman, who’s my
Mission Operations Manager, who’s, if you’ve seen
“Apollo 13,” you know, the Ed Harris character
that runs mission control, that’s Alice, except she
doesn’t have a crew cut. And, I mean, she called
this a nine-year sprint, meaning we were busy the entire time, making our plans, checking them twice, planning for different flybys, if we found hazards we had to dodge, getting all the malfunction
procedures together, doing all the crew training
for the ground crew for what if this happens,
what if that happens. There’s a chapter in
“Chasing New Horizons” called Battle Plan Pluto, which tells the whole
story of what it takes, the inside story of what it takes to get ready for one of these one-shot, it’s going to work or it’s
not going to work flybys. If you only can read one chapter and you want to nerd
out, read that one, okay? – [Woman] Thank you. – You’re welcome. Last question. – [Woman] Thank you so much for your talk, this was really interesting. Based on what you were asking us earlier, my question is, do you think
Pluto is a dwarf planet or a planet? (audience laughs) – I guess that’s fair. So, there’s a story behind this. Which is in 1991, right as I got my PhD, I published the definition
of a dwarf planet. It’s a small type of planet. So those are not mutually exclusive. Dwarf planets are a type of planet. And to planetary scientists,
that’s always been the case, with very rare exceptions,
I’m sure there’s some small minority that has some other idea. All right, and everything you know about this planet controversy comes from a misunderstanding, where astronomers passed some resolution in a
professional society meeting in 2006, and got it very wrong. And somehow, the scientific press didn’t look at that critically
like they should’ve. Planetary scientists
never use that definition in any research papers, because it doesn’t make any sense. And it’d probably be
about as bad a situation as if planetary scientists tried to make categorizations of galaxies. It’s not our technical specialty, we would get it wrong. We might have our heart
in the right place, but we’d flub it up. Another example might
be that if, God forbid, you should ever have a
neurological problem, you would want to go to a neurologist. Not some other type of doctor,
let’s say a podiatrist. You wouldn’t go to a foot
doctor to have your head fixed. Don’t go to an astronomer
to talk about planets. In planetary science, the small planets, the dwarf planets, are considered planets. You’ll find that all through the published technical literature. And if you go to a professional planetary science meeting, like the
Division of Planetary Sciences or the American Geophysical Union or the Geological Society of America, or any of those meetings
and just sit quietly in the audience during talks, you’ll hear those worlds called
planets 100% of the time. We don’t know what else to call them. So Pluto and the dwarf
planets are planets, and I’m not alone in this, this the way the professionals categorize. But thank you for asking the question. And with that, I get to go to dinner. So thank you all very
much, thank you, Steve. (audience applauds) – To everyone, thank you so very much for your participation. Students, as a professor,
I just want you to know we didn’t bring Alan here to set him up on a pedestal for you to marvel at. We brought Alan here to inspire you, to drive you on to all the
great future opportunities you have in your careers. So thank you Alan, good night, Boiler Up, Hail Purdue. (audience applauds) – Thank you. (upbeat music)

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