Well good afternoon welcome to NASA headquarters in Washington, my name is Duane Brown with the Office of Communications
NASA's new Horizons research team is back to reveal even more
Unprecedented images and science that continue to be returned from the new Horizons spacecraft
Following its historic July 14 flyby of Pluto
But to set the stage for today's briefing
Please welcome to the podium astronaut and head of the NASA science Mission Directorate
Where New Horizons is one of almost 100 science missions in the directorate's portfolio ladies and gentlemen dr. John Grunsfeld?
Thank you very much, Duane, and you know this week has been just a phenomenal week on
Monday we released the first image from the epic Earth
Polychromatic imaging camera on the discover mission the deep space climate Observatory the Blue Marble, this is our first
You know true Blue Marble of the earth since
1972 when the Apollo 17 astronauts took the famous Blue Marble image of the earth and it really
Paints I think just an incredible picture of our home planet
And how you know lucky and precious planet Earth is
Especially when you compare it to the amazing views. We've recently gotten from the dawn spacecraft
You know which is a somewhat series?
hostile world dwarf planet Ceres
We've just announced yesterday a Kepler discovery of a sort of a parallel a cousin
solar system to that of our own solar system
With a G's type star much like our Sun a little bit older and a an
Exoplanet that's about 60% bigger diameter than the earth in right in the middle of the habitable zone
It's it's truly amazing the things that we're doing but
The images that we've been getting and the science, we've been getting from Pluto
is really just been you know more than amazing and
proves definitively a
scientific theory that science never sleeps
and
If you look at our panel here
They actually look pretty cheery for a group of scientists that have not been sleeping for the last few weeks
But they are here to tell us about the most recent
Amazing results from the Pluto New Horizons mission, and I'm just thrilled to be here to hear those results
Okay me
So we have
before I introduce our panelists for
this afternoon
obviously the NASA accounts social media buzz
With this mission and the results and the images follow the NASA accounts on Twitter
YouTube Facebook and
Other NASA accounts and send in your questions
At hashtag ask NASA and a lot of questions are coming in we're trying to answer those as quickly as possible
But keep them coming in and you can follow the conversation
And there's still a lot of conversation all over the world on this historic mission at hashtag
Pluto flyby and
again online all of the information today and in the future
can be
obtained by going to
WWE gov slash, New Horizons
First up you will hear from Jim Green director of planetary science and NASA headquarters
Allen Stern New Horizons investigator at Southwest Research Institute in Boulder, Colorado
Michael Somers New Horizons co-investigator George Mason University, Fairfax, Virginia
Cathy olkin New Horizons deputy project scientists also at the Southwest Research Institute
And world MacKinnon New Horizons co-investigator at Washington University in st
Louis and with that I'll turn it over to Jim
Thank you very much to Wayne you know July 14th was very historic
For NASA with our very successful flyby of the New Horizons spacecraft through the Pluto system
And we're just ten days from that and yet. We've only had about an opportunity to see about 5% of the datum as
Many know we stored that data on board as we flew through the system
And it's just now starting to come back each and every day the science team has been huddled
looking at the data as it comes back and it's always surprised and
and it's just quite a pleasure to be to be part of that team to look at the data when it comes in and
See the new discoveries that are coming out now
Day, we're going to talk about some of that latest data that came in within the last few days
This is a spectacular set of data
but it's also data that happened and was taken on board stored prior to the encounter and
It's post encounter after the spacecraft had an opportunity to fly through the Pluto system and look back
To Pluto as it's hurtling away at more than 16 kilometres per second these are just
Amazing discoveries and so without further ado let me turn it over to the principal investigator Alan Stern to start it off Alan
Thank you, Joe. Well as Jim said
Last week the United States through our project in NASA
Explored the farthest frontier ever explored by humankind the Pluto system
And we can't tell you how happy we are just to be back as a team and to tell you what we've been discovering
We came back last Friday and gave a first report
About just the first couple days of data download and the first reactions that we had to it now
We're ten days out seven and a half million miles from Pluto. We've had more time to think about
the data sets that are on the ground and
Equally importantly we have about three times as much data on the ground
Now that as Jim said it's not very much of the total data load. We have about four to five percent of the data back
95 or 96 percent of it is still on the spacecraft, so we're only scratching the surface
And we've got some great discoveries to tell you about we also want to tell you that
Besides the data sets is one other way on this project to know that we've really done the exploration
We're on the other side of Pluto and that's this bumper sticker. That's inspired by Val maldor our
Deputy systems engineer that says my other vehicle explored Pluto. It's got a nice picture of Pluto made by New Horizons in the review mirror
that's how you know I
Want to say a few things and I'd like to call up my first graphic. Which is just a hauntingly beautiful
image of the double-planet system
Pluto Charon with Pluto on the left and Charon on the right this was made a few days out on approach
with true color added from our Ralph instrument on top of a lorry image and
As I tell you a little bit about where we are in the mission
Just feast your eyes on this
We've never been to a double planet system before and it's turning out to just being a really be a scientific Wonderland
We've now finished the first phase of
Downlink that was an intensive 10-day period in which we sent down images and spectra and other datasets
Just to whet our appetites and tell us the basics about the Pluto system and the discoveries that you'll be hearing about
by myself and Mike Cathy and Bill
Report on some of the most important findings that we've already made in these few days
We're now moving into a second phase of downlink. That's a little bit different, and I think it's important to everyone understand that difference
Will be transmitting home now a lot of engineering data from the flyby as well as data from our plasma are in
situates our student dust counter
Header data to go with the images inspector that we've already got and so for the next couple of months until we reach mid-september
It'll only be occasionally that will have new images
on the ground and available to release but starting in September the spigot opens again and
Then for about a year maybe a little bit more the sky will be raining presents with data from
From the Pluto system, it's gonna be quite a ride
We're really happy about the amount of interest in this mission as a mission team
We're excited to share it with all of you, and we're going to do some of that right now
We're gonna get right into the science
For some of you if you if you're seeing a cardiologist you may want to leave the room
There are some pretty mind-blowing discoveries that we're going to talk about and if I can have my second graphic
I want to show our two-by-two mosaic of the Pluto system this has twice the
resolution of the previous best global image of the approached hemisphere and and really it's just it's just
Mouth-watering the level of detail is spectacular
this image has a resolution of about 2.2 kilometers per pixel and I
Think just looking at it
You can tell as our science team can that Pluto has a very complicated story to tell
Toto has a very interesting history
And there is a lot of work that we need to do to understand this very complicated place
I want to stress that I want to drive it home by
Showing you this image at higher magnification, so if I can go to the next time step
We're gonna look at just the northern half of that image, and we could we could easily
Blow it up even further and you can see across the northern terrains here
Which include the North Pole by the way
And this is a true color image essentially true color as your eye might see it a whole range of geologic expression
Kathy and Bill will be talking about this quite a bit more, so I won't steal their thunder
But just let your eyes gaze from the left on the Western limit
Across the disk over to the east and you can see different geological units different kinds of features
It's telling that complicated story again, which is there for us to unravel?
And if I can have the next time Steff and we can go to the south you see a still more
complicated story with the great equatorial dark regions with
with Tombaugh regio as we informally call it the heart on Pluto and
What looked like massive tectonic features?
Both radially emanating from Tombaugh regio as well as others that run more or less north-south. You'll hear more about that later
I do want to tell you about one aspect of the interpretation that we've been making over the last week in
Looking more carefully at the imagery of Tombaugh regio or the heart?
Like a real heart it has
Two lobes on the left and and on the right side the left is the western side
And I think even to your eye you can distinguish a difference between those two the right lobe looks like a much thinner deposit
That's been painted on top of the topography and our
interpretation of that that material in the right lobe as well as the material emanating to the south below the Western lobe is
That in both cases we believe the source for that material is
The Western lobe that it's material is being bright material probably nitrogen snow is being transported off
the source region of the Western lobe
but perhaps by winds and Aeolian transport perhaps by sublimation and
Winds and then recon dense ation or perhaps by a process we haven't thought about but in any case
We think that we're coming to understand this feature just a little bit
It is early days bill may have a little bit more to say about that
What I want to talk about next is our next time step, which is a false color image
Which has really been stretched to show the dramatic differences in
Color units on Pluto and how they correlate with the geology. This is pretty mind-blowing Cathy's gonna
Have a lot more to say about it what it means in the bigger picture, but as you can see for example?
Tombo Reggio with the western and eastern lobes that I was just talking about have different colors
They're telling us something in that and soon. We'll have composition spectroscopy to support that at very high resolution
You can see that the polar regions
have a different color still and that as we get down into the dark equatorial regions is still more information that geology and the
Probably the composition seem to be correlated and this this tells us that the payload that we brought
To bear on the reconnaissance the Pluto system was really the right payload because we have onboard the spacecraft now
tremendous datasets with higher resolution color than this higher resolution pan chromatic mapping for doing the geology and
a spectacular data set with compositional information
with over
64,000 pixels that we've put on the surface to get a spectrum at every location
We're gonna be able to tell this story very well over the next year really looking forward to that
I'm gonna move on to the next time step
Tell you a little bit about atmospheric science where we've also made some advances
This this particular view graph is to illustrate something about our ultraviolet occultation
of
Putin's large moon Charon. This is an experiment that we designed years ago to look for an atmosphere around Pluto's largest moon
There's been a pretty big body of literature
Speculating about how Charon could have an atmosphere?
We just got this summary data down in the last few days. We don't yet have the full spectral data set in fact
We won't have that data until September, but if you look at that
that
Time step, you'll be able to see the little yellow line represents the path of the Sun as seen by the from the spacecraft
moving behind
Charon and you see it just clips the northern
regions of the moon that's exactly what we plan that's exactly how we plan this trajectory to go and
Just as you a clip on either side of the
The body you can see in that red and white graph that the light level from the Sun
Just plummets straight to zero doesn't look anything like
The solar occultation data that we showed you last week for Pluto where we could clearly see a refractive
Signature a slow decline in light levels here. It's just basically a square wave telling us that Charon has much less atmosphere
than Pluto if any
We really can't put strict bounds on it yet because we don't have the spectra but as I said
We'll be able to do that when we get out to September because those spectra will be downlinked
for now all that we can say is it's much more rarefied atmosphere and that confirms our our preflight notions our pre encounter notions and
We're really looking forward to seeing just how rarefied that is it may be that there's a thin?
nitrogen layer in the atmosphere or
Methane or some other constituent, but it must be very tenuous compared to Pluto again
Emphasizing just how different these two objects are despite their close association in space
I want to also speak to another part of our atmospheric science
Which is the fact that we've now got to the ground some of the radio occultation data for Pluto where the Deep Space Network?
Transmitted a powerful signal up to Pluto timed to arrive
just as the spacecraft was passing behind the planet so that we could measure the refractive index of the atmosphere and
As you'll hear more from Mike we got it
We got the data there beautiful data
And they have a wonderful scientific surprise the pressure in Pluto's atmosphere
Measured at the base of the atmosphere for the first time in history is lower
Substantially lower than predicted, and that's probably telling us a story and Michael have more to say about that
I'd like to to close with one more time step. This is really a spectacular image
This is a silhouette of Pluto looking back after the flyby. I think this is just fantastic
This is our equivalent on New Horizons of the Apollo Earth rise photograph that proved
We were there you can only get this image by going to Pluto when crossing to the far side and looking back now
It's striking and spectacular as this images emotionally it also
Represents a huge scientific discovery because you see above the dark disk of Pluto a band of light
which is actually telling us that Pluto has a haze layer in its atmosphere and
Mike's going to tell you more about it
Okay, Thank You Alan good afternoon everyone. I'm going to talk about two
New results on the atmosphere that are basically changing the way we think about Pluto's atmosphere
We're having to start from scratch to understand
What we thought we knew about the atmosphere the way where there were and the way the climate and the evolution worked
So could have the first time step, please
The first graphic, please
Okay, this is one of our first images of Pluto's atmosphere
Now this was the image that stunned the encounter team
For 25 years. We've known that Pluto has an atmosphere, but it's been known by numbers. This is our first picture
This is the first time
We've really seen it this was the image that almost brought tears to the eyes of the atmospheric scientists on the team
Could I have the next step please?
Okay now why do I tell you now is it what you're seeing here. This is the atmosphere backlit by the Sun and
The light the Crescent that you're seeing is
Light sunlight scattered by small particles in the atmosphere and these particles constitute a haze layer
Now the inset is a cross-section of that haze layer showing structure the colors have been enhanced
They're not real colors. Just so that you can see that. There are in structure. There is structure
There's an argument going on in the team whether this is dynamics or chemistry
It's probably both, but the real answer is that this is our first peek at weather on in Pluto's atmosphere
Okay, could have the next time time step just to illustrate that a little bit more
There's a hint that there is either a layer of haze at
30 kilometer team isles 50 miles or a
combination of layers and waves in this region
Those are the kind of things we're going to have to sort out over the coming weeks
And that's going to tell us about the details of how the atmosphere actually works
But the haze is extensive it extends at least 100 miles above the surface. That is a big surprise
That's five times further than our models predicted
Models predicted that haze particles would form low in the atmosphere where the temperatures are cold
But it's forming high in the atmosphere where the temperatures are hot or at least hot from Pluto's perspective
Which is not hot from our perspective, but nonetheless. It's a mystery
That's one of the things that we're going to have to sort out in the coming days
Okay, the is pretty. It's it's a way to see the atmosphere
But it's a piece of a big story that we're trying to understand from Pluto and that is how the atmosphere and the surfaces are
Connected so I have a simple animation to illustrate one aspect of that connection could it have the next time step, please
Okay this shows how?
Methane in the upper atmosphere is broken apart by ultraviolet radiation from the Sun into
chemical
Components radicals and small atoms and molecules that react trigger a set of chemical reactions that form complex
Hydrocarbons like ethylene and acetylene which were detected by New Horizons as time goes on these build up they become
supersaturated, and they should
nucleate to form haze particles which then grow and
Eventually they will get big enough so that you'll see a haze layer
And they were fall to the ground at some point in this cycle
Those haze particles are chemically processed to produce what we call tholins which can leak chemically altered
Hydrocarbons that have a red color, and we think that that is how?
Pluto's surface got its reddish hue and in a minute Kathy is going to talk more about the color and the composition of the surface
But this is just one piece of that story. It's not a coherent piece yet
There are some mysteries as I said we don't understand why there's a haze layer up to a hundred miles altitude
It really is a mystery
Okay, the next story regards surface pressure, and it will just give you a little bit of context here
in a planetary atmosphere the surface pressure at any level is a measure of the weight of the air above that level and
Weight is gravity
acting on mass
so if you know the surface pressure of
a planet faster you think he had a pretty good estimate of the total mass of that atmosphere and
That's important because that's a way of
Quantifying the global state of an atmosphere okay, so I can have a next plot the next graphic, please
Okay chose surface pressure on Pluto as a function of time now the units might be a little bit strange to you
They're in micro bars a micro bar is one
Millionth a sea-level pressure on earth and the timescale. There is from 1989 up to just before the present
Now what is interesting here?
Is that a 1989 Pluto is at its closest?
Distance to the Sun and now Pluto is moving away from the Sun, and it's very elliptical orbit as it moves away
It should be cooling the nitrogen should be condensing onto the surface and the mass should be decreasing
But we don't see that we see the exact opposite that has been
very interesting nonetheless
We have been trying to figure this out
well what I'm going to show you now is a
New data point some more information that we have to add to this story. It is just one data point, but I do want to
Say it is significant and we are going to have to figure it out ok, so this is this is it
this is what wrecks the radio science experiment has contributed to this story a
New data point which shows that the surface pressure is at most 10 micro bars
That's an upper limit so the mass if you will of Pluto's atmosphere has changed by a factor of 2
It's decreased by a factor of 2 and about 2 years
That's pretty astonishing at least to atmospheric scientists, and so that's telling you something is happening now. It is just one data point
These are early retrievals. We got more data coming as Alan says and there's more to the story
But it's another mystery that we're gonna have to deal with over the next few weeks months years and so on
Ok and I'm going to turn it over to Kathy Hawken who's going to talk about the color and composition of Pluto's surface
Thanks, Mike, so I'm gonna tell you about the color and composition and try and tie this together so that you can
understand what we know from this color the color is really an
indicator of different surface compositional units so if I could have the first time step
This is that same false color image that Alan showed
And I'm going to talk through it and tell you what we're seeing
Scientific some of the things that we know when we understand from looking at this image
So first of all you can see the dark region down at the bottom of the image
That's near the equator
And that's the darkest region and you
Remember there's dark regions all around that area even on the other side of Pluto and then just above it
It's a little bit brighter and a little less red and then at the North Pole you see the bright
Brighter Isis so if I could have the next time step
putting this latitude and longitude grid on the image allows you to
Help see your draw your eye to that banding pattern now
I want to talk a little bit about it because it goes to the complexity that Mike was just talking about about the
Atmosphere and the surface in the interaction Pluto has a very complicated
seasonal pattern of transport of ices over it takes 248 years for Pluto to go around the Sun and
Pluto has a very eccentric orbit so sometimes it's much closer to the Sun than at other times
also
Additionally Pluto's North Pole is tilted over at an angle of about 120 degrees
Relative to the plane that it orbits in all of these factors together
Cause us different parts of Pluto to get different amounts of sunlight
And the sunlight is powering the sublimation of the ices from the surface into the atmosphere and so
Some parts are kind of baked like near the equator and other parts
Receive these condensation of these ices as you can see on the North Pole here
And so we've got a differing pattern that you can see
Manifested on Pluto that we understand from modeling of the seasonal seasonal transport of these ices
But there's one glaring
Difference in this pattern that I just called out and that is Tombaugh regio
next time step, please
Tombo Reggio
clearly interrupts this pattern of
latitudinal
variation of colors and brightnesses
And one thing I should add is that those darker regions in the the story
I was telling of the seasonal transport are likely the tholins that mike was describing that we're raining out from the Haze's or
falling from the atmosphere in the Haze's
Now what's really special about the Tombaugh regio region is that we're seeing methane nitrogen and carbon monoxide
ices there
This is telling us something that we need to
Understand on the northern part of Pluto we see methane and nitrogen but not carbon monoxide
So maybe what we're seeing in Tombaugh regio is a source region for some of these specific ices that?
complicates in addition the story of this seasonal transport that I was telling you about
We're going to be looking at that in the future as you've heard
We have a small bit of our compositional data down and we'll get a lot more information when we get the rest down
But we've got some great images and Bill McKinnon is going to tell us about the geology of
this Tombaugh regio region and near nearby vicinity
Okay, can I have my first graphic?
Next please
Albey looking at the our fabulous
Near encounter hemisphere and there you see it
You can start the animation and what we have now is a full seven frames of what will ultimately be a twelve
Frame mosaic at higher resolution, but not even our highest resolution that will come down later this
area
and in the next slide
Next
Yes, so this area this mosaic covers
In its entirety this vast more or less flat
IC plane that we have been informally calling butt-nik platinum, it's pretty big in fact
it's just about the size of the state of Texas and
All around the periphery and then the interior of Sputnik Planum our
Geological wonders and I'd like to share some of those wonders with you, so could I have the next slide
Please so
first I'd like to look at that Orange Box a rectangle that you see at the upper left of the
mosaic next slide please
So this is the northern boundary of Sputnik Planum?
There's a little scale bar down there, but basically this is about
250 miles across about the distance between, Kansas City, Missouri and save Louis a city
Which I picked completely at random okay?
Okay next slide
So I've marked some things here to help help sort of guide this tour so most of the picture you see is really split nic
Planum and it's famous or what really well known for having this sort of
Segmented or cellular structure, we just call it sort of political or poly you know almost fully all
terrain and you can see this really well as you move to the left side of the image where the
Contrast between the bright and dark shows up, but at the top of the picture. It's really different
There's a rugged landscape there a degraded landscape and something that to a geologists eye looks like something that has been very
deeply and
extensively eroded and we can tell it's old as well because you can see with your own eye various impact craters of
of large size
But what's really interesting to us is the actual?
interaction between the Sputnik Planum and this rugged terrain to the top if you look carefully at
the image you can actually see a pattern that indicates the flow of
viscous ice
towards
The scarp or cliff boundary at the of the rugged terrain
We call these streamlines and when you look at these streamlines, which I've marked with those curved arrows that you see there
They look just like and we interpret them to be just like glacial flow on the earth
But I don't have to remind you that glaciers on the earth are made of ice you know like in Antarctica and Greenland
But water ice at Pluto's temperatures won't move anywhere. It's a mobile and brittle but on Pluto
The kind of nitrogen the kind of ices we think make up the Planum
Which Cathy just talked about nitrogen ice carbon monoxide ice methane ice these ices are geologically?
soft and malleable even at Pluto conditions
And they will flow like in the same way that glaciers do on the earth so we have actual evidence for
basically recent
Geological activity now if I could just back up for one in fact one more thing. There's one
Arrow all by itself there. It's hiding up at the 12 o'clock position. We can actually see a flow of this
what is probably dominantly nice solid nitrogen ice flowing through a breach in an old impact crater and
partially filling in the interior of that crater you
Know and like Kathy said we we knew that there was nitrogen ice on Pluto from spectra
We've known this for years
And we we imagine that nitrogen was sublimating or evaporating one place and condensing in another place, but you know
We to see evidence for recent geological activity is simply a dream come true
And I want to back up just one one one little bit and say when I say recent
I don't necessarily mean yesterday
I mean geologically recent
But the appearance of this terrain the utter lack of impact craters on the Sputnik Planum tells us that this is really a young
unit and
We have models of what the flux of Kuiper belt small Kuiper belt objects would be on to Pluto and they give various answers
But the best ones imply that these the ices of Sputnik Planum, and the flow features we see in fact
I should even point out that those curved arrows up at the upper left there
We can actually see them going around what looked to be barrier islands
It's really to us a kind of conclusive evidence for flow
But just to get back to the age
The age is only a fraction of solar of the total age of the solar system probably no more than a few
tens of millions of years and
What we know about nitrogen is what we know or?
Kinetically estimate about the heat flow coming from the interior of Pluto. There's no reason why this stuff cannot be going on today
Okay, so let's go to the next time step
So now we're gonna go down to the bottom of Sputnik Planum there and to that orange rectangle, and that's blow that up
This is a very busy scene okay?
and
It's a bit bigger than the one I just showed you so
This one's about 400 miles across so that's like taking a drive from LA to Phoenix although
It's not it's a bit colder than that I suppose anyway next time step, please
So here's some things are marked up actually at the very top of the image. You can still see Sputnik Planum
You can still see it's polygons and at the very bottom is this ancient
black
heavily cratered region
Which we've been informally calling Cthulhu Reggio
At the very right of the image at 3:00 at the three o'clock position are a group of mountain blocks
Which we discovered last week, and we all informally named Norgay Mantes
But in this picture you can see kind of in the center well actually
If you go a little bit above in the center then towards the left
Another range or arrangement of mountain blocks and these mountain reach mountainous regions two of them are actually somewhat similar
You might you might think the ones on the left are different
But that's just because the Sun is
higher in the sky when that picture was taken and so you don't see the shadows quite as prominently the
Arrangement and appearance of these mountain blocks is similar from ones one region to the other so we've given an informal name
This new mountain block
after Sir Edmund Hillary who with Tenzing Norgay first summited Everest back in 1953
The scientifically interesting and fascinating thing about this picture to me
Is that the Sputnik Planum ice these mobile ices seem to have moved and surrounded and invade the?
Mountain the Hillary Mantes and in fact they seem to they cover up not just or not just in
Imbalance around the the mountain blocks, but they extend all the way down
and they just seem to feather out just at on to the edge of
the cthulhu
Reggio and in fact when you look at it in detail
there's a lot of fine structure in the ice between the Mantes and the Cthulhu Reggio and a
lot of fine structure that is
different than the
different scale of finer scale then
The polygons we see throughout most of Sputnik Planum that tells us that the ice in that intervening region between the mountains and Cthulhu is
substantially thinner and in fact one more fun thing you can see is that if you look just at the edge of the of the
Dark unit you see sort of circles of of this bright mobile ice one's called in filled craters
So there are craters that have basically ponds of this probably dominantly nitrogen ice in them
Okay, so let's put this all together and let's take a flyover from one end of
Foot Nick Platinum to the other I could have the animation, please
So we're gonna start at the north
And we're gonna Corrine over the cliffs on to split Nick Platinum, there are the ice floes around the islands down there
There are the polygons well delineated, and as we move into the interior of Sputnik Planum
It seems like the polygons disappear, but they don't if you look carefully they're still there
They're just obscured by brighter ices and if actually basically are approaching the region that is
Super rich in the carbon monoxide ice that Kathy was was just talking about
anyway, it's a long flight all the way to the south, so we'll skip over that part and we'll
Rejoin our our our tour here coming up on the Hillary
Mantes there they are
We're sweeping across the big block small blocks and bits the Cthulhu Reggio the dark
asphalt
cone surface ancient Athens surfaced on the right and as we move over the Hillary Mantes at
One of those big craters with the big ice pond is coming into view
That crater itself is about the size of the DC metro area
And as we move off the Hillary Mantes coming into view over the horizon on Pluto are the norgay Monte's
Now the screen has gone dark, but there's a whole lot more that we're going to learn about Pluto and its moons
Just as Alan said and Jim said most of our images
Most of our data are still on the spacecraft
Outbound from Pluto and will be downlinking this in the months in fact over almost a full year or more ahead
With that give it back you Dwayne thank you
Okay, so now we're going to transition into questions and answers and we're gonna start here in Washington
and then hit the phone lines and social media to come back and
Frank I'm gonna give you the first question because your expression that's pretty cool stuff, right
It's Frank whoring with Aviation Week or dr
McKinnon just I have questions about a couple of things that I saw in the new disk image
it looks like a
Like a copyright mark just to the west of the of the plane
It's a big crater
I guess with some concentric circles
And if you have any idea what that might be and then also just to continue on the on the ice floes
Do you have elevation data as to?
What's making it flow and is it flowing down into the mountains is the plane higher than the mountains?
So I think you're probably talking about there are some circular features I didn't particularly point out in the full disk image and
To the west and to the north of of
Sputnik Planum, and if the indeed of Tombo Tombo
itself
And those are probably impact craters of some scale maybe a hundred and fifty or up to
250 kilometers wide so some parts of Pluto are probably at least
Fundamentally ancient even though there may be active geologic processes, and it's near a few with central Peaks, which well those are smaller
But I think he at the scale looking at the big picture of Pluto. You'd be really looking at the very very distinct circles
We'd have to look at I think he was thinking of the one we informally call Elliot crater
You can actually even see it in this image
So you mean the one just up at the 10:30 position off the edge, is that the one you mean Earth? Are you yeah?
Yeah, yeah, oh yeah
That's another crater. Well. That's it's not really showing on my particular graphics, but it's another one of these craters that
Has bright ice in it probably as a remnant, but it also has a central peak so the central peak is dark
and it's sticking up through a bright ring and
your other question was
elevation yes
We have we just we had you know we measure the elevation of some of the mountains by just measuring their shadow lengths
And if we don't have shadow lengths we use another technique called photo clinometer II which is basically
determines the relative
Slope and we integrate and determine
And it's called and we get some estimate of the topography and we can actually see on the Sputnik Planum
that the individual polygonal cells are a little bit higher than the
boundaries between the cells by a few tens of meters
And the but the the primary technique we want to use is called stereo
Imaging and we don't have our data yet to do that stereo analysis
But we are going to get more frames of that mosaic and then we're going to get a whole sweep from an entirely different
set of
Observations covering the whole basically of Pluto and we're gonna have a beautiful
Stereo view of weather on the whole whether it's but Nick on him is high or low
With respect to things nearby the one thing you can certainly tell though just by eye
Is that the north the Platinum is lower than the cliffs and it appears at the south?
Where it's let's say it seems to on lap on to cthulhu Reggio, so it's kind of a gradation abound
Thank you. Do you have another question good? Okay? We'll go here, and then we're gonna go to the phone lines
uh, yeah, Eric came with science magazine if I could follow up with with with Bill I
Could get you to speculate maybe about what could be driving these flows and imbalance and also
What how this source region got there to begin with?
There's been debates. You know whether this is
Isis that have accumulated from above you know layers of frost turning into I guess play sure like things over time or whether
You know something is allowing Isis to well up from within so can you explain?
How this this this intriguing spot right in the belly of the planet got to be there?
And and then what's driving it well you you've sort of but answered your own question
But you know we have a region a vast region that seems to be truly a reservoir
I mean it is you know we make it?
We've described as poetically as the beating heart of Pluto
The it may be the supply zone the supply the supply Hut for the entire atmosphere for a lot of geologic activity
Ultimately how it was formed you can imagine
Different things you could you could go all the way back in time and imagine it was really an ancient
Impact Basin or maybe it's something else completely different we see at the margins to the south. There's a jumble of mountains
There's highly deformed topography we know that geological activity beyond just the flows that I've been talking to you about
Have deformed the crust there. We don't really we can't fully explain what's going on because we've only
Seen these seven images
Close up and so with all of the rest of that stuff comes down and when we get some of this stuff
Uncompressed on the ground. We'll have a much more complete story
But you can imagine as as I use the word reservoir you can imagine with any reservoir
I mean it could be filled in from the side by glaciers flowing into it. It could be filled in from below
You could imagine that
inside the icy crust of Pluto there's enough pore space and cracks where
nitrogen would actually be a liquid because it would be warmer inside Pluto as it is inside all planets with respect to their services and
This reservoir of liquid nitrogen could actually supply the planet we don't these are all
interesting ideas and as Michael was saying
It's very early days, and we're having or enjoying a great deal of animated discussion, yeah
And I just like to add one thing which is that these images?
Nothing like these images existed. Just a couple of weeks ago, and we're sort of reacting to it in almost real-time
But what we're learning and very fundamentally is that on Pluto we have a much more
intimate and intricate
interaction between geology and the
volatile transport and the seasonal climate cycles those kinds of things that are
forcing one another in feeding one another and creating a very complicated and layered story about the planets history and
It's rare in
The pantheon of objects in our solar system that we have seen this kind of an intricate and and complicated story
I'm reminded in some ways of Titan
For example, but few other examples that are so dramatic. It's it's it's brand-new
Yeah, I mean just you wait till the rest of those images come in because I know there's gonna be great stuff there
Okay, let's go to the phone lines
And then we're come back here for social media and any other
questions and the audience for a wrap-up and on the phone line first up is Kim Chang for the New York Times, Ken I
Think you remind me of the temperatures what temperature is Sputnik Planum that allows these glacial flows
What the temperatures atmosphere at the surface and then higher up with the haterz?
The temperature at the surface is about 38 degrees Kelvin which is
380
Zero Fahrenheit
So that's incredibly cold if you want to talk about the ices on it
I mean I stupid sure yeah well and but in case even at 38 Kelvin though solid
Nitrogen can creep and below ground that nitrogen will warm up a little bit, and it's very sensitive to temperature
So there's nothing physically
implausible about
19 glacial flow no not at all even if there's just a modestly deep layer in
Sputnik Planum you get down to just tens of meters and it may be much deeper than that the overburden
The pressure from the overburden of ice can actually change the the properties of the nitrogen because it's getting warmer so that it's more
It's less viscous and much more able to flow there may be even conditions where you can get
liquid nitrogen flowing below
A deep layer of ice of tens or hundreds of meters and that may be part of it part of this story as well
But we've got a lot of work to do to be able to say that with any confidence
Hey next up is Irene what's
Brother's Irene a couple questions the first I think it's for on Michael summer ISM. I think I heard you say that the
Surface pressure measurements show that the Pluto atmosphere had
Decreased by a factor of two in two years could you just tell us what that?
Two-year-old dataset is and how accurate that is compared to what you're getting with New Horizons
Yes the the data that I showed that time plot
For Pluto's atmosphere is based upon stellar occultation
z-- where we follow the sunlight behind
Pluto's atmosphere and look at the extinction of that sunlight to get a measure of how much gas is there
So we have to use those stellar occultation
Z-- to extrapolate down to the surface to get a surface pressure
And that's what was done for each of those blue data points that you saw
As far as we can tell those are accurate measurements of the atmosphere where the stellar occultation occurs
the thing that's different about Rex is that with radio waves you can go right down to the surface and
The data the Rex data look extremely good the error is really tiny just a few percent
So this should be our best
Measurement of the surface pressure or include them again, this is early this is our first data. This is our first retrieval
We've got more studies to do on this
but
Taking it at face value
Yes
It appears as if the atmosphere has
Changed in Mass by quite a bit and Irene just as context all those blue data points those stellar occupations our data
That was obtained from the earth only the red data point has obtained from the horizons
And so we're we're we're detecting what may be a really significant short-term
variation in that atmosphere
It might be a turnaround even we'll have to see and now what will really help
I think is the most recent observations from Sofia
Which is of course?
one of our
747s it has a fabulous telescope that most recently in the end of June
Raced down to New Zealand and chased Pluto's shadow as it. Also was occulted by another star and got a very beautiful
Occultation and so that's a very recent occultation that could be easily compared with the Pluto data for which it then might help
interpretation of previous observations a
Really good point. I mean did you have a follow up see the reddish hue and the
Theory that perhaps. It's these um. You know chemically altered
Methane that are raining down these toll lanes. What would it?
What would that look like if you were on the surface of Pluto with the particles be big enough to see like snow or ice?
or fast or
And also why would they not be or are they universally distributed?
Do you think and then?
something else happens on the surface, and I know this is putting together a puzzle when you know all the pieces but
This is kind of curious what though what you're thinking on that is right now
Yeah, there's several questions there one in terms of what it would look like we're talking about a very very thin
Haze if you were on the surface of Pluto looking up you probably would not see it
we only see it when we're looking through long slant links through the atmosphere and
Even then looking at sunlight scattered off these particles is the way we're able to get that bad image
So it's a very thin haze, but it's distributed over a very large region it appears to be like a hundred kilometers
I mean hundred miles are so high in
terms of the conversion of those particles to tollens
We don't know the exact details in that
Dolan's that term income a range of different chemical substances that appear to be
altered hydrogen
Hydrocarbons and nitrogen compounds that have been irradiated or they're gone through some chemical process where the hydrogen's have been kicked off
So it's not a particular
Chemical substance and so with that having more detail we can't really test the exact mechanism
but we do know that these substances are around we see them on Titan for instance and
The reddish color is fairly distinctive so yes a puzzle
There are lots and lots of pieces and the chemistry is certainly one of those pieces and I can add to
Address one part of that question that the person was asking is that?
I believe there was also a question about the Haze's
Falling you know
uniformly on
The surface of Pluto and that probably does happen and so we have a lot of work to do to figure out the rate of
that deposition
But the story of seasonal transport was the one that I think reveals why we see a distinct different pattern
With these land
Latitudinal bands, and it has to do with those tollens. They're darker. They're gonna absorb more light
and so the ices will become
Volatilized they'll go from a solid into a gaseous phase
And then be deposited onto the poles light and so cover up up perhaps the thorns that have been
deposited on the northern pole
And so I think this is going to all be pieces of this puzzle that we put together to understand the rate of
production of tollens and the deposition of it I
Mean did you have another follow up I?
Might have kind of one other big-picture question, which may be too early to answer but drum for Alan
Based on the data that you've gotten so far from your eyes
And can you say anything about the exact mass of Pluto and any changes in?
In the models of what the interior may have thanks, thanks Irene
I'm gonna start that I'm gonna ask Bill to chip in as well because this is a particular area of his research interest
we have not been able to obtain a
new mass estimate for Pluto, but before the flyby ground-based data already gave us a
Very accurate mass and in order to constrain
The interior properties the primary uncertainty was in knowing the radius
So that we could get the volume and then convert to a density and what New Horizons was able to really contribute
even as we were approaching the planet was to discover what the true radius is and it's
1185 or 1186 or maybe 1187
Kilometers so we had an uncertainty that ranged over. Maybe 70 kilometers
we've collapsed that to sort of plus and minus two and
It's centered around 1186 so now that we know that it's somewhat bigger than many of us expected
That will lower the density and have implications for the interior properties which bill can speak to
yeah, the
Basically everything Ellen said is is pretty much the case we we have
decent masses for both Pluto and its companion Charon
And we have good sizes for both and so we now have accurate density values
And so you know in in the past years past we thought that cheran was very icy and Pluto was
Had much more rock in comparison now the bodies are in fact more similar
But you know right now still seems to be the rockier world of the two and this will go into
Building you know new models and testing new models of the evolution of the system in terms of what the inside of Pluto is
Without gravity data, it's hard to be absolutely definitive
It's that's kind of one way we test our models of planets when we fly by them or orbit them
But everything we see all the activity we see on Pluto is
consistent with the idea that is it does have a
massive rock core, surrounded by a huge
Icy shell and that I shall then by being a more ice
Planet is probably a little bit thicker and all other things being equal. It raises the
It increases the part of the probability that there may still be an ocean way down underneath a very thick layer of ice now
That's a theoretical inference right now
But it's something that we're keeping in mind as we explore Pluto one of the things we also learn not just a size of Pluto
But we also learned that it was very very close to spherical we actually can't detect any
oblate Nisour out of roundness in the body
And you know some of you sometimes you who run around the solar system and look at this satellite or that satellite
And they're very distorted this tells you about their history
Pluto probably was spinning very very fast
after
what we believe to be a giant impact that led to the formation of its satellite so
after this formation Pluto and Charon are very close together
much like the earth and the moon and
tides between the two caused the orbits to expand and the bodies slow down and then they are now locked up the way they are
But Pluto doesn't show any evidence
In its shape from this early fast rotation
So we think it must have been really warm enough that no residual shape could be supported so
This is it's still too early to say exactly you know how hot
Okay in that kind of business
but that's the kind of thing that will be you know applying our research tools applying our theoretical models and
Going to scientific conferences and running in writing scientific papers and either coming to conclusions or not
That's how it goes in science, but things are looking good for Pluto
Hey killer, BT scan telescope Kelly
Thanks very much um I wanted to ask
Because the atmospheric density is higher than you
Expected it to be I'm wondering
I think this is for Michael probably can you tell us anything about the possibility that argon is playing a role in the composition?
The Rex measurements suggest that the pressure is about a factor of two less than previous measurements
So it's gone the other direction we believe that the atmosphere has shrunk to put it crudely
That by itself. I'm not sure it says anything about Oregon
I don't believe at this point we have anything that we can say about our gun
Next Jason Rehan Space Flight inside I hope I got that last name right Jason
So I blame no problem this one goes out to Allen
It's you called Pluto a couple times during this conversation a double planet
Considering that Pluto is larger and far more dynamic than previously thought
what a new horizon is finding say in terms of how we define what the planet actually is you know there's any kind of a
bone of contention
with those who followed Pluto for some time now, so
If you tell us a little bit about that and thanks for doing this
Yeah, sure Jason and not to sidetrack the conversation
But you know we we call the Pluto system a double planet
for a very specific technical reason because the two objects are close enough together and
Their mass ratio is sufficient to draw the balance point between them out of the primary out of Pluto into free space between
That's exactly analogous to the way that we define a double star system when the balance point called the barycenter
Is between the two bodies and not in the more massive of the two the earth moon system is sort of on the border
It's not quite there in fact the balance point the earth moon is
Deep in the Earth's mantle, but not at the center of the earth
so it's not yet moved out of the planet, but close so I don't think there's any controversy at all about the
Double planet moniker. You know there's been this controversy where astronomers
and planetary
Scientists have largely been on different sides of it
I think that you and the public just like we on the science team could pretty well
Tell what we're dealing with it's very hard not to call an object like this of this level of complexity the atmosphere
with potentially an internal ocean certainly with complicated seasonal cycles and
certainly the big
complicated system of moons a
Planet and you no way science works is individual scientists make their decisions one at a time and eventually
Consensus is reached
and because we've made so many discoveries both with missions like Kepler the doctor Grunsfeld referred to of
Different kinds of planets around the galaxy and now a new class of plant in our own solar system
We're going through a period of transition and those definitions are in transition as well, and it'll shake itself out
But one scientist at a time until we reach consensus
okay, Leo in right from Irish TV gonna have the last phone question and then
Social media is chomping at the bit, so we're gonna get to the public around the world watching this program at Leo
Okay doing thanks very much Abdul McKinnon mentioned a hypothetical
Ocean I was trying to understand how that might fit into what you're saying to put it crudely. Could you say that the new?
nitrogen glaciers could be explained quite easily
without a liquid ocean underneath
That the other mechanisms could achieve this, but that Noah Gaye and Hillary simply cannot be explained without something like that
Okay, I should be very explicit. We don't have any
Direct evidence for an interior liquid water ocean from these images what I was trying to imply is that?
Our picture of Pluto as a complex active world plus the fact that any ice massive
Ice mantle if you will on Pluto will probably be deeper than previous models basically
Increases the theoretical likelihood that there might still be an ocean down there
Okay, so let's see what the social media conversation and questions are Emily
This first question is from Derrick, and he asks what information is used to create these false color images
Yet, so the information comes from our Ralph instrument and Ralph is two parts it has a color camera and an infrared
Spectrometer and the color images come from the color camera we have four different color filters
That's broadly a blue channel a red channel a near. IR Channel and a methane channel and they cover
Wavelengths from point four to say 0.9. Microns where charge-coupled devices see cds
Are typically?
sensitive and so those images are a combination of those different filters combined and
Sometimes we'll combine them to make it look like natural color and other times
We create a false color image so that you can pull out those wavelengths like the near-infrared
That's closer to 0.8 0.9
Microns that our eye is not sensitive to so that we can understand these
Compositional units in a detail that we couldn't with just our eye
Great thank you, um this next question is from Linda
And she asks the ring around Pluto is from its atmosphere would images of planets without
Atmospheres be able to be captured like this, and I think she's referring to the black image
I'm sorry
Could you repeat the question sure the ring around Pluto is from its atmosphere would images of planets without?
Atmospheres be able to be captured like this
images with that
Yeah, I should say yeah you
Sure, we we've taken silhouetted images
Of other objects that don't have atmospheres, and then you don't see the ring extending above the surface in fact
We have a very nice image
That just came to the ground hasn't been released yet
There's some optical artifacts because we're looking back into the glare of the Sun
That actually was taken about the same time on the same day
Closest approach day that showed the Crescent of Pluto's big moon Charon, and there's no evidence of an atmosphere there
Whatsoever you just see sort of like a brand-new moon just a thin Crescent of light
It's quite a haunting image, and once we clean it up. We're gonna make sure it's released
Let's take two more and then we close out here
This question is from Simon
And he said is there a theory of what is driving the nitrogen ice flow and could the sun's light be responsible even though
It's so far away. I
Guess that's for me um
it's
not sunlight its internal heat if you have a thick enough a
Massive enough layer of these kind of ices whether it be nitrogen or carbon monoxide or methane
It will move if there's a sufficient slope it will move
In fact we've done some theoretical calculations, which of course we to do better ones, but we we believe actually one of our leaders
I'll just put it this way our leading model actually for the formation of the polygons at this moment is internal
convective motion
rising and falling at a slow rate of the nitrogen ice within the Sputnik Planum as
Long as that ice is at least a half a mile deep we think this process can operate
Less, but and I just say it's driven from the heat that is leaking out of the interior of Pluto
I'm sorry one more and then
Give you the final one Eric. Then we close that okay sure
this last question um
When will we see the surface of the other side of Pluto in relatively high res?
Well, we've got
About the best images on the ground already of the opposite approach hemisphere the nature of New Horizons
exploration of Pluto
Demanded that we or was a consequence that
We were gonna observe one hemisphere in exquisite detail and the other side in much less detail
That's the combination of our very fast speed combined was Pluto's slow rotation rate of about six point four days
So the last time that we saw the far the far hemisphere we were
3.2 days out half that 6.4 days and that correspond it to almost three million miles away as
Opposed to the imagery that you're seeing that was taken when we were much more than ten times closer
So the net is that we have a dichotomy in our maps the far side is not imaged as well
We get the basic patterns
We can detect perhaps the largest craters on the surface and the largest units
But not nearly as well as on the close approach hemisphere. That said we do. Have a good bit of imagery
that's still in the spacecraft that will help us improve the farside maps a little bit more and
In the fall when those data start to come to the ground
We'll be able to produce a better map of that far side than we have now
Alright, thanks. Yeah Eric Han with science magazine again um
I'm a sphere question for Alan or Mike so this this this shrinking atmosphere this this plummeting pressure
Does this I'm assuming that if it got to zero that means that the atmosphere froze out does this mean that?
You got there in the nick of time and that you know that's where Pluto is heading
Toward towards a freezeout and and as a follow-up to that how can you reconcile a shrinking atmosphere with with detecting haze?
much higher than than was expected that seems a little bit contradictory to me talk about a
Shrinking atmosphere with with a much more dispersed or higher haze particles. I'll talk about the haze first
The haze particles are extremely small and they're very buoyant they can stay up in an atmosphere they can stay
Suspended in an atmosphere. That's very very thin so you could have
Yeah, I'm just pulling numbers out of the air right here
But you could have the the atmospheric pressure decreased by a factor of 10, and you could still have a haze present in the atmosphere
You you could suspend less, but it could it could still be there
If you want to take the the other part, I'll let you sure sure well
You know for a long time there have been atmospheric models and climate models for Pluto that
Suggested that his little draws away from the Sun that the atmospheric pressure could precipitously drop and in fact
During the time when the National Academy and other committees were looking at
Flying a Pluto mission and and its relative priority
There was a real interest in trying to get to Pluto while it still had a substantial atmosphere that helped motivate the case for
y2y to get a mission launched in the 2000s versus waiting because we wanted to get there while there's still an atmosphere to study and
Eventually there came to be a sort of belief that well. It's been 25 or more years since
Puddin's closest approach to the Sun. Maybe there's not going to be any atmosphere of collapse what Rex seems to have detected is
Potential for the first stages of that collapse just as New Horizons arrived. It would be an amazing coincidence
But there are some on our team that would would say I told you so so
We'll see if this some this is in fact
What's happening, or if it's a more complicated story perhaps not related to atmospheric collapse or some other possibilities as Mike said?
It's early days. We have several more Rex datasets to come to the ground
There will it help inform this question because we actually got data from two different stations
At ingress and to different stations that egress and we only have one of those four and only part of that data set
So this is an unfolding story
That's gonna do it here as you heard today Pluto is
very complex
world and as dr
Sternin mentioned the data is raining down and we will be bringing you more in the future stay tuned for updates
on the cadence of how we represent that share it with the media and the public in the world and
again follow us on the NASA social media accounts twitter
facebook youtube
Send in those questions keep them coming in will get them answered with the science team and hashtag and NASA and follow the conversation this
Conversation is going to go on for a long time at hashtag
Pluto flyby and again
Updates and any other type of information coming down in the future
Wwas a gulf New Horizons
Congratulations to the team have a great great weekend, and this team is not rewriting textbooks
They are writing the textbooks. Thanks for joining us
