David Grinspoon on New Horizons and the Weirdness of Pluto

In the book “Chasting New Horizons: Inside the Epic First Mission to Pluto,” authors Dr. Alan Stern and Dr. David Grinspoon recount the riveting history of the quest to send a spacecraft to the planet Pluto. In this episode of Stuff to Blow Your Mind, Grinspoon chats about the book, the planet and the nature of space exploration.

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Episode Transcript

Speaker 1 (00:00):
My lul. Welcome to Stuff to Blow Your Mind, a
production of I Heart Radios How Stuff Works. Hey, welcome
to Stuff to Blow your Mind. My name is Robert
Lamb and I'm Joe McCormick. In Today, we're bringing you
an interview with Dr David Grinspoon. That's right. Uh. Dr

(00:23):
David Grinspoon is an astrobiologist, award winning science communicator, and
prize winning author, and is a senior scientist at the
Planetary Science Institute um YES and he is the co author,
along with Dr Alan Stern, principal investigator of the New
Horizons Mission. They're the authors of Chasing New Horizons Inside

(00:44):
the epic first Mission to Pluto. This was a really
fun conversation. I'm really glad we've got to talk to
David about Pluto, about space exploration, about planets in general.
And I think you are going to love this conversation.
That's right, even if you're not that into Pluto, or
you think you're not that into Pluto. Uh. Is also
some venous talk in there, so it's it's tremendous. Definitely
check it out. We're just gonna dive right into the

(01:05):
interview and meet you on the other end. All right, well,
thanks for coming on the show on Stuff to Blow
your Mind. Would you please introduce yourself to our listeners.
And my name is David Grinspoon. I'm an astrobiologist at
the Planetary Science Institute UM and I study planetary evolution
and I get involved in some spacecraft missions to other planets,

(01:28):
and I've I've written a few books, most recently Chasing
New Horizons Inside the Epic First Mission to Puto, which
I co authored with Alan Stern, who was the h himself,
the leader of the Epic First Mission to puta awesome man.
I just want to stress to everyone listening this is

(01:48):
a great book and if anyone is scared off from it, thinking, oh,
I don't want to read about space probes and a
far flung dwarf planet, I just want to reassure them
that this is not only a very insightful book, it's it.
It really has and it really is a narrative of
the adventure in many respects. So I wanted to ask,
how did how did you come to write, uh, to
come to co author what some have called a nonfiction

(02:11):
Michael Crichton novel. Well, I like that, UM, I like
that description. Yeah, Well, this story, the story of New
Horizons and of the exploration of Pluto, is one that
I've been following closely for a long time, uh, much
longer actually than there was a mission called New Horizons.

(02:32):
There was an effort to send a mission to Pluto,
and it just so happened that being a planetary scientists
and coming up through you know, grad school and and
all that, at a certain time that a lot of
the people that I'm close with and friends with um
and have known for a long time have been caught up,

(02:54):
uh and became part of this this effort. So this
was a struggle that people were going through who I
knew well for for decades, and at times it seemed
like a very quixotic journey, like there's no way this
is going to happen. I can't believe what these guys
are going through. I can't believe they're not giving up.

(03:14):
And and I remember thinking, you know, well over a
decade ago, probably a couple of decades ago, Wow, you know,
if these guys ever actually succeed in doing this, it's
gonna be a great story. It's gonna make a great
book someday. It's gonna be a great book anyways, because
of what these guys are going through. But if they
actually succeed, it's gonna be an amazing book. I remember
thinking that, um. And then more recently in UM I

(03:40):
guess two thousand and fourteen, when New Horizons was actually
approaching Pluto, finally Alan Stern, who I've known for a
long time, approached me and said, hey, I'm thinking of
I want to write a book about New Horizons, and uh,
I want to do it with with a co author,
and and you're my first choice. And um, I was.

(04:04):
I was really psyched. I mean, you know, when you
get an offer like that, what's the right answer? You know, yes,
of course. And so so we agreed to enter into
a partnership and and try to tell the story. UM.
And you know that had that had its own kinds
of challenges because obviously Alan's relationship to the story is
very different from mine. And how are we gonna sort

(04:25):
of combine our two perspectives and U and tell tell
the story where he you know, he's a character in
the book. UM, and it's it's his mission. But we
we worked really hard on that and thought about how
we could use that as a strength or that you know,
the kind of combination of our two perspectives, and I, uh,
it was. It was tricky, but I think we succeeded

(04:46):
in producing a book that that not only tells a
pretty exciting story, but does it in a unique way. Absolutely. Uh.
You know, at time treating this book, I kept coming
back to a question that I guess made may sound
a little cheeky, but but also probably gets to some
of the challenges of the space exploration. Whether it's harder
to send a spacecraft to Pluto or to successfully push

(05:07):
a mess mission proposal through NASA. And I want to
come back to that, you know, get your thoughts on that,
but but I thought it might be nice to touch
on that, that first challenge and uh, you know the
amazing methods that we use to send spacecraft through the
Solar System. Would you tell our listeners about our early
dreams of a grand tour and the time frame for

(05:27):
capitalizing on what you describe is excellently described in the
book is a kind of stargate. Yeah. Well, um, I
love the first part of your question, So we definitely
need to get back to that, because yes, it's there's
some ways in which it's harder to navigate h Washington,
d C. Than than um, than the outer Solar System.

(05:47):
I don't know. Both both have their own challenges and
you have to learn how to be good at both
if you want to do this. But um, the Grand
Tour um, Yeah, so well, it's it's very difficult to
send the spacecraft as far as Pluto um. And if
you were just going to launch from Earth with a
normal rocket and just try to head out there, it
would take um, well much longer than the New Horizons took.

(06:10):
You know, when New Horizon basically took only a decade
to cross the Solar System. It would take longer because
the distances are so great. But um, you can take
advantage of something called a gravitational assist where you fly
in close to a giant planet with a huge gravitational pool,
and if you aim and just the right way, um,

(06:33):
then you use the gravity the giant gravitational pool of
that giant planet to sort of sling shot you around.
You know, it pulls you in, but you miss the
planet and then it flings you out and you have
to aim just right. But you can use that to
get a boost, a big pick up and speed, which
makes it much quicker to execute the rest of your

(06:56):
journey across the Solar System if you've if you've done
everything right. And the first time this was really used
to dramatic effect was the Voyager mission. The Voyager missions
which we're you know, our first close fly bys of Jupiter, Saturn, Uranus,
and Neptune Voyagers. They launched in nineteen seventy seven, the

(07:17):
Neptune encounter, a Voyager two was which was the last
one was nine. So all through the late seventies and
in the eighties, these missions were going planet to planet
and sort of expanding our our knowledge of our Solar
System and dramatic encounters. And there's a certain element of
luck there that a lot of people really aren't probably

(07:40):
aware of. But if you look historically, I mean, you know,
we started sending spacecraft to other planets in the sixties
and you know, the Venus Mars in the sixties, and
then um started thinking about farther, going farther afield, and
it just so happens that occasionally there's a lineup of

(08:04):
all the planets and just the right way so that
if you launch at the right time, you can sling
shot past Jupiter and then that sends you to Saturn,
and then you sling shot past Saturn, and that sends
you to Uranus, and then to Neptune and then to Pluta, etcetera. Um.
And but you have to picture the planets have to
be lined up just right, sort of like beads on
a spiral going out from the Sun, and that alignment

(08:27):
only happens every couple hundred years. And the amazing historical
luck that I that I was mentioning that people aren't
aware of, is that in the late nineteen sixties early
nineteen seventies, scientists became aware, you know, just when we
were gaining the ability to launch spacecraft off of birth
and going to the planets for the first time, scientists

(08:50):
became aware that one of these what they call Grand
Tour alignments was coming up in the late nineteen seventies
and eighties, so that if you launch to spacecraft by
the mid to late nineteen seventies from Earth, you could
do this Grand tour and go all the way out
to Earnest Neptune, Pluto. But if you missed that window,

(09:10):
that nineteen seventies window, you wouldn't get another chance like
this for a couple of hundred years, so so you know,
it started just in the nick of time, but it
was also a rush to launch because this. People realized this,
and the scientists proposed a Grand Tour in the early seventies,
and then Congress said, no, that's too expensive, go back
to the drawing board. And they were like, well, we
don't have much time to get this together. You know.

(09:33):
There was some drama there, but they reproposed and Voyager
got approved, and the Grand Tour mission became the Voyager mission,
which culminated in uh in the encountered the amazing encounter
with Neptune and it's moon Triton in nine with Voyager two,
and as we tell in the book Chasing New Horizons,
in a lot of ways of that encounter set the

(09:56):
stage for the desire to go to Pluto because with Neptune, uh,
you know, it was sort of all over for that
generation and people, young scientists were like, well, wait a minute,
there's more to explore. What are we going to do?
And Triton, which was the last place the Voyager went,
little moon of of Neptune is is a very sort

(10:16):
of Pluto like place of really strange, icy world with
solid nitrogen basins and all this strange activity and geography,
and it made people think, gosh, if we could only
send a mission to Pluto. And right sort of in
the wake of the end of the Voyager mission, at
least the Voyager planetary encounters was born the desire uh

(10:41):
you know, it really a nine for this, this crazy
idea of sending a mission to Pluto, which culminated, uh
you know, twenty six years later with a successful fly
by of Pluto by New Horizons in two fifteen. Now
you were talking about gravity assist there, and and of
course that what ultimately became New Horizons, the New Horizons mission,

(11:05):
and went through You discuss all the different sort of
versions of the proposal. At one point the proposal was
actually actually involved sending a craft towards the Sun first. Right, Oh, yeah,
there was one UM trajectory that would have worked um
as far as using these gravitational encounters to get to Pluto.

(11:25):
But it would have involved going towards the Sun and
flying by Venus first and then back by Earth, and
which is by the way, something that is UM done.
Uh you know, that's actually how both both Galileo and
Cassini on their way to Jupiter and Saturn both did
Venus five bys um. Sometimes you go in and pick

(11:47):
up speed and then you fling back outwards. But it
was really not optimal for a small Pluto mission, and
it was It would have worked, but it would have
taken more years um and it already takes a long
time to get out to Pluto um and also um.
I mean it would have saved energy and money, and

(12:07):
that's the other thing. You're not just doing this to
save time on the journey. You you want to launch
a smaller rocket and still have enough energy to get
to uh the outer Solar System, and that's where these
encounters help you also by kicking up speed. So it
would have worked, but you also it's not optimal because
when you're designing something to endure the coldness of the

(12:29):
outer Outer Solar System where Pluto is, you really don't
want to send that spacecraft in towards the Sun and
endure the thermal environment near Venus if you can help it.
So it was one of the things that came onto
the table to possibly save the Pluto mission, which had
to be done multiple times when things got canceled and
the budget got constricted or whatever. But it turned out

(12:52):
to not really be the best way to do it. Yeah,
you lay out, you know, all the close calls that
just the you know, the the quest to send a
craft to Pluto went through. How many close calls were there,
and how astounding is it that the mission happened at all.
It really is kind of a Perils of Pauline story,
you know, where everything that can go wrong almost did

(13:15):
go wrong. UM. And you know that's that's part of
part of why I love the story, because we wanted
to let people know not just what happened and how
it was done, but really what it takes to get
something through the system and all the different things that
can derail it. And this story kind of combines all
of those hazards it. Uh, it had to be Um.

(13:37):
It was canceled by two different successive presidential administrations. UM.
And that you know, one of the risk of these
things is the time scale is long enough that you
get it through and the government finally says, yeah, we're
gonna fund this, we like it. And then you get
a new government that wasn't our idea, forget it. And
this happened multiple times, UM. And then you know, they
sort of kept changing the rules on new horizons. And

(14:01):
then there you know, there were so many interesting crises.
One was had to do with a nuclear power that
you have to have a nuclear power source when you're
going that far from the sun um, and that introduces
other um hazards. I mean just just in terms of
the regulation. Uh, it's crazy getting something like that approved,

(14:21):
especially when you've got a ticking clock and you have
to launch by a certain date or you're gonna miss
your Jupiter fly by window. And so that was tricky.
And then all these things happened. Lost Lost Albumos Lab,
which is the only place where they make the plutonium,
got shut down because of a security breach um and uh,
they weren't gonna have enough time to get enough plutonium.

(14:41):
And you know, so that's one whole area of of intrigue.
And and you know near Mishap and then you know,
there were there were a couple of just unfortunate technical accidents.
There were um, you know, there was a lot of
kind of like political um uh just maschinations within NASA

(15:02):
and outside of NASHA that outside of NASA that doomed
seemingly doomed to the mission again and again. And and
this team, this crazy team of you know, they called
themselves the Pluto Underground that were committed to this goal.
They kept having to pick themselves up and dust themselves
off and basically start again. And UM it's really it's
really an amazing story of perseverance that they just didn't

(15:25):
let it go. Yeah. I mean not only the you discussed,
not only like the technological hurdles and then of course
the political sphere, but but even just within the realm
of space exploration, like suddenly, given that that grand times
span for the for the project, Uh, new new things
become exciting just within the realm of space exploration that
can potentially detract from a mission like this, right, yeah, absolutely,

(15:48):
So you know there's something that something comes along. You know,
again we're talking to an effort that started really succeeded
in two fifteen, and you know, it's a shifting landscape.
New discoveries happened, UM, new constituencies form with a NASA
to do do other kinds of missions. I mean, for instance,
one thing that that came along UM during this time

(16:10):
period was that Europa, the icy moon of Jupiter got
much more interesting in the in the sense that we
discovered UM with the Galletle mission. We discovered that Europa
likely has an ocean and is a possible habitable environment.
So um, the Pluto mission is doing well, and then
all of a sudden, there's this huge movement within the

(16:31):
planetary science community to divert resources and compete a mission
to Europa instead because of these discoveries, and and you know,
nobody on the New Horizons team is going to argue, well,
Europe is not interesting and not important. I wouldn't argue
that that for second. Everybody, you know, we all acknowledge
that these are all important goals. But there's the shiny

(16:51):
new thing all of a sudden. You know, we've been
waiting our turn, you know, so that things things like
that happened multiple times. I actually have heard of like
a planetary partisanship before. You know, I had a friend
who did some research on Jupiter's moon Io and she
had some kind of negative things to say about Europa. Well, okay,

(17:12):
I mean there is there is definitely an element of that.
And in a way, then the way NASA sets up
it's UM it's competition for missions UM kind of encourages that.
Because there are these different UM interest groups within NASA.
There's like I mean, I'm really interested in Venus exploration.
So I'm part of this group called VEX at the

(17:33):
Venus Exploration Activities Group, And there's me PAG, which is
the Mars Exploration Activities Group, and then there's the Outer
Planets Activities Group. And you know, when we when NASA
does their annual decadal ranking of mission priorities, were sort
of organized into these different constituencies and we're all putting
our favorite mission forward. So there is this competition, um

(17:56):
and then even beyond that, when there's a call for
new mission, you know there's going to be a small
or medium class or large class mission. Different teams compete,
you know, And I've been on these teams and you
put years into these missions, and you compete really hard.
So of course you want your mission. I mean, I
want my Venus mission that I'm a co investigator on
to be selected. And then when an asteroid mission or

(18:19):
a Jupiter mission or something gets selected instead, I'm really
bummed about that same time. So that's true, and that's
partly just a measure of the way we compete things.
But I do have to say, and I and this
is really true, that there's a larger sense in which
we're all um on the same team and feel that way.
So that when the competition is over and one of

(18:40):
these missions comes to the launch pad, whether it's a
Mars mission and asteroid mission, uh whatever, everybody in the
community cheers that launch. I mean because we all, you know,
when you back up from that, we're all pretty psyched
about exploring the whole Solar System. And even though you'll
hear me and some of my colleagues grumble about, oh my,
got another Mars mission got funded, about Venus, what about

(19:01):
you know, but then then when that Mars mission actually
launches and land successfully, we get tears in our eyes too,
and we're like, this is so amazing. So you know,
we yeah, we compete for our separate constituencies, but we
all I think also um genuinely um root for and
identify with the larger project of of exploring the sol
war system. Yeah, I want to be clear in case

(19:22):
my friend is listening, she I think she was joking
when she was slagging. Well, I mean, we do joke
about it, you know, every scheme and like Mars, I
hope people you know, but at the end of the day,
we're I mean, and you know, of course you get
personal um, grudges and all, you know, and there's human
human beings are human beings. But at the end of
the day, uh, we're all pretty excited about about all

(19:45):
of the exploration. All Right, we're gonna jump in here
and take a quick break, but we'll be right back.
Thank and we're back. I found it really astounding, especially
to think about this as we were at the very
close of the decade as we recording this. But at
one point, I think during two thousand you mentioned that
NASA to shelve the idea of a Pluto mission altogether

(20:08):
until the twenties. So I think it's it's amazing to
think that there's like an alternate timeline out there in
which you and Alan might have written a book about
the desire for a Pluto mission in the twenties rather
than what we have a definitive history of the planet's
first exploration. That's right. I mean, there's so many alternate
timelines like that, And this was a case where basically, um,

(20:31):
you know, more than once NASA let it, you know,
got to the stage where there's going to be a
competition for this mission, which is a huge win for
the people wanting to go to Pluto. It's like NASA
sponsoring a competition for proposals. That means that they're going
to pick a winning proposal and then somebody gets to
fly mission a Pluto and hopefully it's our team, but
at least it's some team, so that's great. But then

(20:53):
they have this competition and everybody works really really hard
on all their proposals and you know, it's just crazy
the amount of effort to get this in and then
NASA says at the end of it, well, actually we're
not picking anybody, and um, the whole concept is is
canceled um because a budget problems. And by the way,

(21:15):
we're just not going to go to Pluto for the
next twenty years. So that was actually something that was
declared by the Associate Administrator of NASA at one point,
and that was really a low point for the morale,
as you can imagine. But there were interesting things that happened,
um at that point. Um, there was a big public
interest campaign that was the Planetary Society got involved. There

(21:39):
are a group that advocates a public membership group that
advocates for planetary exploration and other um, you know, the
public got involved and there was a lot of pressed
about this, and people were like demanding, no, we want
our government, we want NASA to send a mission to Pluto.
And then NASA got tens of thousands of letters saying
you can't cancel Pluto, we want this. And so there

(22:01):
were points, and that that point you mentioned where it
was completely canceled was one in particular, where the public
input became really key to keeping the effort going. UM.
And you know, of course there were efforts by the
Pluto underground to sort of help marshal that public interest

(22:21):
and encourage letter writing, but at the same time it
was really genuine. There was there was indeed an outpouring
of mass public support. And UM. That's another thing that's
interesting I think about the whole story. Was it at
the heart of it, there's this band of sort of
I guess I don't want to quite call them fanatics
but almost but like you know, really uh determined UM

(22:44):
scientists UM who wanted to do this UM. But then UM,
there's also the larger planetary scientists community that had to
be sort of won over to their cause. And then
and then outside of that there's just the public that
got very in all then at times UM. The support
of the public was pivotal in UM keeping the effort

(23:06):
going and ultimately and ensuring a success. So we know
you have a special place in your heart for Venus,
and maybe we can come back to that later on.
But what is so captivating in particular about Pluto. Well, Pluto,
of course, you know, historically it's been the place that
we just didn't know anything about UM and uh so

(23:27):
it was you know in science fiction from the golden
age of science fiction in the you know, sixties, seventies, eighties,
when we really didn't know anything about Pluto. It's this
UM it's kind of mystery world UM. And there's a
lot of great law laura about Pluto. But then, of course, scientifically,
once we started to learn about the existence of the
Cooper Belt, which is this whole third realm of the

(23:51):
Solar System. You know, you've got the inner rocky planets,
the outer gas giants, and then the outer outer Coiper Belt,
which is this vast zone of these icy and rocky objects,
you know, millions of them beyond the orbit of Neptune
that we didn't even know about. All we knew about
was Pluto. It turned out we discovered really in the
in the ninetees that Pluto is the tip of the

(24:12):
iceberg of this huge unknown realm of the Solar System,
and so that in itself made it very interesting to
want to go and visit one of these bodies, because
those are leftovers from the formation of the Solar System,
you know, they're sort of leftover building pile of building
materials that made the planets. So we know there's answers
out there too, questions of our own origins. But then,

(24:33):
you know, there was always the possibility, certainly in my mind,
and I know in the mind of some of the
other um, some of the people involved in the mission,
that well, what if, against all odds, this thing actually
works and we get to Pluto, and then what if
it's kind of boring. It's cool to get there, no
matter what, but what if it's just kind of like

(24:53):
a a crater ice ball. Um. You know, you've learned
some things, you count the craters, you measure with the
servicement out of it. You know, it would it would
no matter what, it would be cool. But but in
the back of my mind it was like, well, you know,
what if it's just not the most exciting place and
it seems plausible because we have this sort of prejudice
against um cold places that are far from other things.

(25:16):
We expect them to be inactive, and that's you know,
in our textbooks, you know, we thought the moons of
Jupiter would be boring and inactive, and it turns out
there not because the gravitational pull of Jupiter makes them
pulse with activity. We didn't know that until we got there.
By the same token, a lot of people thought Pluto
would be boring and inactive. And the thing that's, if
I had to summarize, you know, and a very short

(25:39):
number of sentences, what's surprising and exciting about Pluto compared
to our expectations is that it's really active. It's geologically alive.
It's not old and dead and just covered with creators.
It pulses with activity, and that is something that nobody expected.
And when those first pictures came in UM, you know,

(26:00):
there was like, in addition to joy and elation and
just share amazement by the the team members, there was
also this puzzlement of what is going on there? Why
is this place so far from the sun. Also, you know,
it's not discovered in creators. There's clearly activity going on there,

(26:20):
and at first it was you know, it really was,
you know, a massive head scratching moment to figure out, okay,
what what's going on? And it it's just so varied
and um active and complex in a surprising and delightful
way that um, you know, I'm still kind of wrapping
my head around that. Well, would you mind telling us

(26:41):
a few like what are some of these most exciting
and like the strangest revelations about this object? Yeah? What
makes Pluto weird? So the first thing you notice, and
there's all kinds of poetry in this, but it's true.
You know, as you're approaching Pluto, even days away, you
see this bright heart shaped see sure, the heart of Pluto,

(27:01):
which is just kind of lovely, but it's also that
turns out to be a very very intriguing and interesting formation.
It's this massive, um huge glacier of solid nitrogen um
called Sputnik Plnacia. A lot of the places on Pluto

(27:22):
have now been named after famous explorers or missions of exploration,
and so we've got Tombao Reggio. The heart itself is
named Tombow Reggio, really, which is the after Clyde Tombaou.
The discover of Pluto. And then the big um western
or left ventricle if you will, of the heart western
smooth area is the Sputnik Plintia, which is this massive

(27:45):
glacier of flowing solid nitrogen. And that was the big
you know. Okay, so you see this area. It's big,
it's bright, and there are absolutely no craters on it.
Zero And I remember John Spencer, who's you know, of
these old friends from grad school. I was mentioning, who's
been involved in this mission for a long long time.
Who's one of the uh, you know, very central. He's

(28:07):
in the book. He's one of the people that helped
UH plan the mission, and UM did a lot of
important work and a lot of the scientific analysis. I
remember him saying on the day of the encounter, if
you had told me that the first that I've ever
told me that I'd see the first high resolution image
of Pluto and it would have zero impact crators, no craters,

(28:27):
I would not have believed you. And that's because craters
are sort of our our chronometers. You know, when you
see a planetary surface full of creators, you know, it's
an old surface that not much has happened to. It's
just been collecting creators over there keons. And when you
see a surface with no craters, then you say, Okay,
something's happening here. There's more recent activities, something filling in

(28:49):
the old holes and paving it over. And this was,
you know, a massive area UM with with no craters.
And it turns out UM that and we know this UM,
but we should have known it because there's no new
physics involved. It was just lack of imagination or you know,
this is why we explore, because you discover things and

(29:10):
you go, oh, I should have thought of that. But
but that that. It turns out that solid nitrogen at
Pluto temperatures is squishy enough so that you build up
enough of it that it does flow over geologic time
with a little bit of heat, and there's a little
bit of heat coming from the interior of Puto, so
UM basically that activity is convicting and flowing solid nitrogen,

(29:34):
which covers this massive area on Pluto. And then closer
and you look, you see like things that are you
realize there's glaciers of nitrogen flowing out of the steep
mountains on the edge of this thing, and the mountains
are made out of UM water ice because water ice
there has the properties of bedrock. You know, it's so cold.
But if you actually look at those mountains, they have

(29:55):
roughly the the height and shape of like the rocky
mountains on Earth. You know, they're like fourteen thousand foot
peaks of water ice with glaciers of solid nitrogen flowing
out of them onto these nitrogen plans. So it's you know,
it's a you can find forms that look familiar and
yet you look at what they're made out of and
they're just really exotic materials. Isn't there also some amazing

(30:19):
precipitation situation on Pluto. Yes, and again it's another one
of these things where it's something that looks familiar, but
it's weird stuff doing it. So on some of the
high mountains, they're they're snow capped, but it's not snow
the way we usually think of it. There are there's
methane snow on top of some of these, so you

(30:40):
have you know, it's it's the same things that you
have on on Earth you have rock mountains and water
ice glaciers and water ice snow. On Pluto you have uh,
water ice mountains with nitrogen glaciers and methane snow. All right,
So as long as we're talking about just the property

(31:01):
to Pluto. I originally wasn't going to ask about this
because I know you you get it a lot um
and but you also discuss it in the book. So
my second grade son is studying the planets in school
and he really wants you to weigh in on this.
Is Pluto a planet? So my one word answer is yes.

(31:21):
But what I would tell your son, because maybe he's
confused by hearing that because he might have heard in school,
but it's not. I would try to use it as
a teachable moment and say, well, here's why some scientists
think it's not, and here's why some scientists think it is.
Because you know, to my mind, what makes something a
planet or not um has to do with its intrinsic properties.

(31:44):
What's that object like, uh, you know, and and in
my view, anything that's large enough to be round by
its own gravity and have um the features that we
associate with planets at you know, surface activity in mountains
and atmosphere, which Pluto does, makes sense to call it

(32:04):
a planet. Um. The i AU definition, which became very
popular in which some people consider to be official although
though I don't UM, it's it's based more on not
the properties of that object, but what's around it, how
it's orbiting, and what's orbiting around it. And you know,
if you're the kind of astronomer that doesn't think so

(32:26):
much about what planets the properties of planets themselves, doesn't
worry about geology and meteorology, but is interested in um
looking through telescopes and identifying orbiting objects and thinking about
classifying your orbits in different ways, then I can see
how that sort of makes sense, UM, But but it
also least leads to some sort of absurdities. I mean,

(32:48):
the basic thing is they say that if a planet
dominates its zone and has cleared out other material, then
it's actually a planet, and if it hasn't, then it's
something else called a dwarf planet, which isn't really a planet.
Um is what is said. The problem is at least
to some silly in my view of silly things like
if you took Earth and moved it somewhere else where
there was a swarm of material, then it wouldn't be
a planet anymore, or even worse, even worse by that definition,

(33:12):
Earth itself was not a planet for its first five
million years of existence, when it was being pelted with
objects that you know, in its zone that had not
yet been cleared out. And then it became a planet
at some point, not because it changed, but because it's
environment changed. So UM, what you will find is that, UM,

(33:33):
there's a difference in the way planetary scientists speak about
this from astronomers in general. And I'm a planetary scientist.
I studied planets for living and me and really most
of my colleagues, I think we use the word planet
when we talk about Pluto. We even use the word
planet when we talk about, um, the larger planet like

(33:53):
moons like Io and Uh and Tighten because because again
they have the feet years that we are interested in
thinking about and comparing between worlds. So UM, I guess
you could tell your son going back to that, that's
some scientists. Um that a lot of the scientists who

(34:13):
study planets use the word planet when they talk about
Puto because it has these things. And then and then
tell them about Puda instead of worrying about the the
definition say, because it has mountains, and it has an atmosphere,
and it's big and round because of gravity, and you know,
hopefully when you talk to kids, you steer the conversation
into something more interesting than scientists arguing about nomenclature and

(34:37):
actually talk about what's cool about Puda. You know, absolutely
now speaking of nomenclature, uh, you also at one point
in the book you talk about the you know, the
naming of the planet and some of the you list
some of the potential names that were thrown out there
at one point. So, you know, if we're considering alternative history,
there's also an alternative timeline where we're not talking about

(34:57):
the exploration of Pluto. We're talking about the exploration of Tomboy,
which was one of my favorites from that list you share, Yeah,
now that was I mean, so the discovery of Pludho
in itself is a really just cool story which we
try to encapsulate in the book because Kai Tombo himself
was a really interesting character and it was sort of
again another kind of against all odds, perseverance wins the

(35:20):
day kind of story which is echoed, uh, you know,
seventy years or eighty years later in the story of
the success of of New Horizons. But when um the
planet was discovered at Little Observatory UM, then um, you know.
They of course, they made sure not to tell anybody

(35:42):
until they were absolutely they checked their work and we
were absolutely certain they had found something. They didn't want
to be accused of a false alarm. And but then
once they were sure, they announced it to the world
and it was in all the newspapers and everything, and
then ideas came flooding in telegrams from from all over
the world, um uh suggesting and letters suggesting names, um,

(36:05):
and some of them are pretty funny. I mean, well,
first of all, there was some there was some politics involved,
like personal Glowal's who was the guy that you know,
found rich Bostonian astronomer who founded the Lobo Observatory where
it was um, the search was successfully executed, and who
actually um really he started the search but didn't live

(36:25):
to see it through. His widow wanted to call it
um percy in honor in honor of first Beloal, you know.
And there were some some politics that had to be
offended off. And then there were some very very silly
um suggestions that you mentioned Tomboy, yeah, because somebody was like,
well that sounds like Tombo, and uh, there's they've got

(36:46):
a great collection of these, uh, at Low Observatory of
the letters suggesting different names for Pluto, but the the
actual name UM I love. This came from a um Um,
a ten year old English schoolgirl named Venetia Bernie who
heard about the discovery of Pluto, and Um mentioned that

(37:10):
Um at the dinner table to her parents, who knew
an astronomer. Um that she had been doing some reading
and mythology and she she suggested Pluto because of its
underworld associations and it's you know, all the you know,
the mythological associations and and this was sent by Um

(37:30):
by by telegram UM and and they loved it at
Little Observatory. And there's part of the reason is because
the first two letters P l um is also honors
personal loal And in fact, the symbol for Pluto, you know,
all the all the planets have kind of a symbol

(37:51):
that comes out of you know, mythology, mostly um. Like
the Mars symbol is you know the male um the
circle would arrow coming out of it, and the Venus
ones the circle with the cross coming out of it, etcetera.
And the symbol that was adopted for Pluto has a
P and an L which stands for Pluto but also
stands for personal loal. So that way they were able

(38:12):
to honor the you know, founder of Deservatory without doing
something so crass is to name it after him. Yeah,
that's awesome. I love the history that you share there
about that. Yeah, because because you go through the history
of thinking about Pluto, you know, and discovering Pluto and
then leading up to this exploration. But of course at
the very start of the book, you you really, you

(38:34):
really to drive home just how delicate these missions are
and how high the stakes are. You open with what
could have been an extremely tragic moment for the spacecraft. Yeah,
you know, we wanted to um structure it a little
bit like a thriller because the people and for the
people that lived through it, um, it was like a thriller,

(38:57):
and that you know, there were long stretches where not
that much was happened, and then all of a sudden,
you know, like the red lights are all flashing and
it's like, oh my god, does that's blooming and and
out of the many sort of near death experiences of
this mission, UM experience, perhaps the most dramatic was the

(39:17):
one with which we opened the book, because um, this
happened on approach to Puto when they were ten days out.
All of a sudden they lost contact completely with a spacecraft.
And that's something that should never happen, of course, And
if it happens when you're a year out for six

(39:38):
months out, then you have some time to work the
problem and try to get back in touch, and hopefully
you do. But when it happens when you're that close,
it's really a panic because you don't have much time.
Not only do you have that initial fear of what
if we never hear from but again, uh, you know,
things do go wrong in spacecraft, and there have been
spacecraft that have been you know, there was one of

(39:58):
the Mars spacecraft UM was made all the way up
basically to the doorstep of Mars and then something went wrong.
It probably blew up and it was just never heard
from again. So those things happen. So that's the initial fear,
and then once they heard from New Horizons it was
a big relief. But what they heard from it was
basically helped, Um, something's gone wrong. I'm not I'm in

(40:21):
a bad condition. What should I do? Um? Which is
good that the spacecraft he knows to say that and again,
if it's six months out, then you have plenty of
time to work the problem. But this was an emergency
because it was literally days away from when they were
going to start the final sequence of observations that that
week long period surrounding the closest encounter, everything's automated, and

(40:43):
it was about to begin that automated sequence, and the
spacecraft is barreling down on Pluto million miles a day,
getting closer, and it's gonna fly by no matter what,
whether it's working or not, and you don't have a
lot of time. And to make matters worse, at that point,
you're so far from Earth with the spacecraft that it

(41:04):
takes nine hours to send a signal to the spacecraft
and get an answer back, So just saying hey, are
you okay, and then the spacecraft saying yeah, well I'm here,
but uh, you know, my main computer rebooted and I've
lost all the commands for the final observing sequence, which

(41:25):
is what it said, And just that bit of communication
takes nine hours, and when you've only got a few
days start executing this sequence, that's really bad. And then
you know, so of course they have this emergency meeting
and they figure try to assess the situation. By the way,
this also happened on the fourth of July, so and
the team had been given the day off to prepare

(41:46):
for the intensity of the encounter to come. So the
phone tree gets activated. People start coming in and there,
you know, flip flops and bathing suits from their barbecues
and UM and like that in their flip flops and
bathing suits. People stayed there for like three days, and
you know, they're sleeping under desks and needing out of
vending machines and all that like Apoblo thirteen, you know,

(42:07):
And and they basically figure out they have three of
these nine hour communication UM turnaround times, three of these
to work with, so they're gonna have to fix the
thing with three batches of commands. That's all the time
they have. And they just get to work and it's
there's there's real heroism in this story, and UM, you know,

(42:28):
we get to UM tell the story of UM some
of these these characters you know who UM been working
out of the limelight for UM, you know, for decades
on this and suddenly have their moment of just like
total heroism, you know, UM, And that's that's great. To
be able to share that with people. Um, and this

(42:52):
team just kicks into kicks into action, and they have
to rewrite all the software and tested it and figure
out ways to send it up and what to tell
the spacecraft and um, you know, nobody sleeps for like
multiple days and um just at the last minute, literally
with hours to spare, they get everything reloaded on the

(43:15):
spacecraft and it's um it ends up executing flawlessly. Um.
But this was you know, this was the moment of
crisis that came after everything else and was like sort
of the last crazy hurdle to be crossed before before
reaching Pluto. Wow, it's an amazing story. It Uh it
makes you wonder what caused the malfunction to begin with,

(43:35):
to get some trans Neptunian malware. Actually they figured that out,
oh really, yeah, you know, and it was a little
bit of an oversight, which is in itself an amazing
part of the story because one thing you read about
is how carefully they tested everything and simulated everything and
accounted for every contingency and tested and retested and simulated
and resimulated. But there was one thing they did, um

(43:58):
slightly wrong, and that us So what happened was the
main computer got overloaded because at the same time as
they were loading up the final command sequences, they were
compressing some other image files that it had previously taken
to make more room in the memory, and they was
overloaded by doing all that. And you might ask, well,

(44:19):
why didn't they simulate that the compression uh and the
loading of the commands at the same time. And the
answer is they had simulated that. But but the images
that they had been using to compress in the simulation
were like fake images of planets. They were like empty,
you know, empty circles to say, here's the planet image

(44:40):
you're going to compress, you know, while you do this,
And it turned out that compared to the real images
that it had to compress, they were um it was
it was more labor intensive for the for the computer
to compress these real images and the fake images they
had gotten given. And so that was the oversight that
caused the computer to get overloaded and trash and cause

(45:01):
this whole thing to happen. So the problem was literally
that Pluto was too interesting kind yeah, yeah, yeah, you know,
but it also just illustrates that, you know, no matter
how careful you are, and these guys. I mean, what's
amazing is how careful they were because you only get
one chance, and unlike earlier missions, there was only one
New Horizons. I mean, you think of all the classic

(45:23):
missions of export planetary exploration. There's Voyager, Viking, all these ones,
these pioneer first missions to places. They did too in
case one of them failed, and sometimes one of them
did fail. But in this case, budget wise and for
other reasons, there was only one small spacecraft, and so
it had to be perfect. So they tested and retested
and had backup systems. But even given all that, there's

(45:46):
just no way you can anticipate everything. And that's why
you need like an amazing team like they had that
can kick into action and solve problems when they come up.
All right, we're gonna jump in here and take a
quick break, but we'll be right back. Thank and we're
back now. Of course, the journey doesn't end with the
with Pluto. Can you tell us a little bit about

(46:08):
Errow cough and the further adventures of New Horizons. Um,
that's right. Pluto was you know, maybe the highlight, but
certainly not not the end of the mission. And one
thing that was kind of innovative actually about New Horizons.
Very innovative was that all along the plan was not
just to go to Pluto, but to go to Pluto
and at least one and maybe more Coper Belt objects,

(46:31):
and and the mission was sold on that basis as
a mission to Pluto and the Coper Belt. But one
kind of crazy aspect of that is that at the
time of launch of New Horizons they did not know
of another Copper Belt object that New Horizons could meet,
that could could could intersect after Pluto with the amount

(46:53):
of fuel and on the trajectory that it was on.
But they had very good statistical arguments as why there
should be such an object and why they should with
no problem be able to discover it before New Horizons
got to Pluto and redirect the trajectory because they knew that,
you know, there were enough objects. They knew that they

(47:14):
just they if you do the math, it shouldn't be
hard to find another place for the Horizons to go
to after Pluto, and you're gonna find that object during
the nine year journey to Pluto. So that logic was
in the proposal and it was pretty good. But then
what happened was as New Horizons was approaching Pludo. Over
all the years it does the Jupiter fly by, it
redirects its trajectory. It's heading out towards Pluto. And they're

(47:35):
searching and searching with all the best ground based telescopes
on Mona Kea and all these big telescopes UM and
they're not finding the right object. They're not finding an
object that New Horizons can get to. And then it
got to the point where it was going to be
too late and they weren't going to be able to
UM execute that part of the mission. And the sort
of the last minute, they called in the Hubble space

(47:58):
telescope and there were some drama there because Hubble, of
course is very scheduled up for other observations and they
had to kind of go to NASA Brass and say, look,
this is really important if you want New Horizons to succeed,
we need to sort of command here a little bit
of time on the Hubble for the search to find
an object. And there was some some drama and some
you know, conflict and then but ultimately they were able

(48:18):
to do it, and literally, you know, it's another one
of these sort of just a nick of time. Uh,
they found an object that New Horizons could visit, which
was you know MU sixty nine originally and then was
given a more appropriate name. But um, but so just
the finding of it was very dramatic. And then um,

(48:39):
but but they did and then um, you know they
did they made the right trajectory corrections so that after
after the Pluto encounter, New Horizons was on its way. Um,
but had to go another billion miles and traveled all
the way from July when they were at Pluto to
New Year's Eve. Um, you know, so another two and

(49:01):
a half years. Um, and um, finally um, this encounter
happened and uh and boy was it amazing Again another
surprising object that uh, you know, you've probably seen the pictures.
It looks sort of like a snowman. But just the
fact that it's this some kind of a contact binary,
these two objects sort of squished together, really reveal something

(49:26):
about the formation of planets and the history of these
objects in the Cooper Belt. And again, you know, they're
just the targeting that went into it's incredible how difficult
it is. It's even harder than the targeting for Pluto.
Because this object is small, you're not completely sure where
it is you're not completely sure where where the spacecraft is.
You've got one shot to image it, you're moving very fast,
and you have to pre program the images in advance.

(49:48):
And just the fact that you know, when they get
that frame down there's actually an object in focus in
the image rather than looking at empty space because you
targeted a little bit wrong. That's that's like people take that.
It's easy to take that for granted because it works
so well, but that's you know, that's a real incredible achievement.
It is amazing. Um. So, one thing I was wondering,

(50:09):
if you don't mind kind of a tangent while we're
out here in the realm of transneptunity and objects. I
was wondering, do you have a professional opinion about something
we've talked about on the show a while back, the
the evidence seeming to indicate the existence of a far off,
larger planet out there that well, I don't know if
you'd use this terminology because of how you feel about

(50:30):
naming Pluto, but what's being called planet nine? Yeah, I
prefer planet X. But um, my professional and my personal
opinion is, um, I hope they find it because it
would be so cool to learn about another large um
uh planet in our in our Solar system, and UM,

(50:51):
I think I'm skeptical just because the history of this
kind of prediction is UM, you know, sort of littered
with UM, you know, with things that weren't found where
people said, I haven't actually found it, but I've found
reason to believe it's there because of the statistical aberration

(51:12):
in UM, the in other orbits UM. There's been a
lot of sort of false alarms along those lines. UM.
But you know, whether or not we agree on what
numbers should be assigned to this punitive planet, I'm with
them completely in the hope that they do find it,

(51:34):
because it would be a wonderful discovery. Yeah, I'm very
intrigued by the idea. Uh So we uh we we
mentioned earlier that we might give you some room to
talk about your passion planet, about Venus here at the
end if you wanted to do do you have anything
to say about Venus? Like what what? What do you
have your eye on there right now? Well, I'm very
much hoping that we do get a mission to Venus

(51:58):
in the next round of NASSASA elections, because there were
really overdue and UM, there's too much mystery about about
that world, considering that it's you know, the closest planet
to us and in some ways the most earthlike other
planet UM. And in particular, now we have more and
more reason to think that Venus might have gone through

(52:18):
a long phase when it was a habitable world. We
used to have this in this picture that Venus maybe
had oceans early on but lost them very quickly on
the runaway greenhouse. But the more we do detailed modeling
of how an early Venus would transition to a planet
without to a very hot and dry planet that we

(52:38):
see today, the more we suspect that that took billions
of years. And so it may be that Venus was
an oceanic planet like Earth for billions of years UM,
which is very intriguing. This picture of these two um
very similar, very very nearby worlds, both of which could
have been habitable for you know, half the or half

(52:59):
the history of the Solar system UM. And so there
are a lot there are a lot of mysteries that
are very compelling as far as understanding how earth like
worlds evolve, how climate evolves, UM and UM. It's uh,
it's sitting right there waiting for us to explore. I mean,
of course, Venus is a hard place to explore because

(53:20):
the surface conditions now are so intense, and because it's
completely shrouded in clouds. You can't observe the surface from
orbit except in the radar. You can't get to the
surface very easily without a really incredibly engineered machine. So
it's not you know, it makes sense that we've explored
other places first, because Venus is not low hanging fruit

(53:40):
as far as easy places to explore, but it's such
a compelling place as far as the mysteries there that
I do think that before long, either NASA or the
European Space Agency or UM, maybe even the Russians. I mean,
there are not there are a number of agencies considering
ambitious new missions to uh of Venus and UM. I'm excited,

(54:02):
and I hope I'm I hope I'm still around when
we really get to UM to answer some of these mysteries.
For some reason, I've often thought or thought for a
long time one of the most haunting sets of images
from the whole Solar System is just those little tiny
slivers we get of the surface of Venus from the
Soviet Venera landers. I there's not a lot in them,
but every time I see them, I kind of get

(54:24):
a shiver. Yeah, I'm with you. I mean there's something
very kind of dreamlike about them, UM, because they look
so real and so sort of familiar in some ways.
I mean, here's a rocky world that's right next door.
And yet because they're you know, maybe enhanced by the
fact that the geometry of these images are so distorted
and we uh, just by the nature of the cameras

(54:45):
that got them, and we only have a few. It's
just it's like this glimpse of a world that we
can't really bring into focus. UM and UM it really
makes you want to see more clearly what's you know,
what's what's over that hill, and what's you know, what's
what's really going on here? And so UM, you know,
next generation of spacecraft that could measure the minerals on

(55:05):
the surface, UM, measure that, uh, the composition of the
atmosphere in a way that we haven't really done yet. UM,
measure what's going on in the clouds where there's a
lot of mystery and even some people think there could
be um, some kind of life in the clouds, I
believe it or not. UM, but then but then also,
like you say, you know, what's what's going on with

(55:27):
those surface images? Really images the surface well and just
give us more of a visual, uh and physical sense
of what that place is like. Um, you know, I'm
I'm very excited for that possibility. We'll tell us what
we can do to help get us back to Venus.
Fun NASA with letters now. Honestly, UM, you know, it

(55:49):
never hurts to talk to your elected representatives, but um,
you know, honestly, I think just you know, when you
have an appropriate chance expressing enthusiasm for the space program
and planetary planetary exploration, uh in general, is is a
good thing. And um, I don't you know, I I
feel like it's I feel like there is momentum to

(56:12):
uh do uh new missions to Venus, like it is
going to happen in the next time scale of the
next next decade. So I'm I'm maybe I'm foolishly optimistic,
but I am optimistic about it. All right. Well, the
book is Chasing New Horizons Inside the epic First Mission
to Pluto by Alan Stern and David Grinspoon. It's available

(56:32):
now and I think all formats correct. Yes, that's right.
It's even it just got uh just got published in Russian.
If you're listening to this program and you don't speak English,
all right, so, uh so that book is is out.
In the past, you've written on on Venus and you've
written on Earth. Uh so where are you headed next?
And how can listeners keep up with your work? Well, Um,

(56:54):
I I have a website, um, Funky science dot net.
And um that's so I sometimes remember to keep it current.
I'm on Twitter as a dr Funky spoon um and
um yeah, I'm gonna be. I'm gonna be. I've got
all kinds of things going. I'm gonna be teaching a
class at Georgetown this spring on how to predict the future,

(57:16):
which maybe that'll turn into a book, I hope. So
and uh you know, just catch me if you can.
All right, Well, once again, thanks for taking time out
of your day to chat with us. Um. You know,
the book is fabulous and we we we strongly recommend
it to all our listeners. Well, thanks to God, it's
been great having the opportunity to talk to you guys.
Thanks David, thank you. All right, So there you have

(57:40):
it again. The title of the book is Chasing New
Horizons Inside the epic First Mission to Pluto by Alan
Stern and David grin Spoon. It's out in just about
any format you could possibly want a book, And then again,
I just have to drive home just how entertaining this
book is. You might not think you want a book
about machines and planets and distant planets, but it is.

(58:03):
It is really exciting. In the meantime, if you want
to check out other episodes of Stuff to Blow your Mind,
head on over Stuff to Blow your Mind dot Com.
That'll set you on the right path. But you can
find this podcast anywhere you get your podcasts these days,
wherever that happens to be. Make sure that you subscribe
and make sure that you rate interview because this really
helps us out. Huge thanks of course to Dr David
Grinspoon for joining us, but huge thanks as always to

(58:26):
our excellent audio producer Seth Nicholas Johnson. If you would
like to get in touch with us with feedback on
this episode or any other, to suggest a topic for
the future, or just to say hello, you can email
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(58:48):
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How Stuff Works. For more podcasts from my heart Radio
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you listen to your favorite shows. The point to four

(59:08):
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