okay welcome everybody glad you could
make it this evening
quick question is anybody exceptionally
warm and don't look at me cuz I I just
sweat okay we would see if we can turn
down a little bit it's kind of stuffy in
here with all these people this is
fantastic
glad you're here my name is Andy sander
as so you may know you're at the lunar
and planetary Institute here in Houston
and tonight is our this is our fourth
presentation in our current public
lecture series exploiting the solar
system today and tomorrow our little
final and fifth presentation will be on
June 2nd with dr. Alan Tremont from here
at LTI giving us an update on where
things are at with the Curiosity rover
on Mars and he's going to talk about the
tires for the wheels I guess so
so if you've been hearing about that
you're gonna you're gonna hear some more
of that at that time a couple of things
you may have seen on here I want to just
kind of reiterate on May 9th there's a
transit of mercury which means I'm gonna
see mercury going across the face of the
Sun slowly but you can see it we're
gonna have a telescope set up at the
Freeman Branch Library from 10:00 to
noon that day as long as it's not cloudy
so you're welcome to come out and see
the transit and it's happening it's kind
of a cool cool little thing to see but
you get to see the Sun up close bring
your sunglasses one of our scientists
David Crane who you've probably heard
speak before he'll be giving two
presentations at the Houston Museum of
Natural Science May 24th and June 30th
as part of their lecture series out
there so if you want to there the flyer
fed out front if you want to go see that
he's a good presenter too you gotta buy
tickets but that's their thing not ours
but this would be good talks if you want
better ones about the lunar exploration
then everyone's talking about the threat
of asteroid impacts so a fun one and
then a scary one to balance it out and
on the flyer it says that it'll be in
the planetarium and that's true if you
look at it online it said it'll be in
there big theater we just found out
recently they're going to do it in the
plant
because they just overhauled the system
and got those nice great new system in
there they're gonna do it there it's
dead
at the end of tonight's presentation the
course we'll have a Q&A session you can
ask your questions if you have it if you
do please raise your hand they'll be two
of us going up and down the aisles there
with a microphone best so course we all
can hear it slow Rossa recording we're
also streaming live on Ustream which we
did the last presentation so again
manners I beg now and of course whoa
just do this there's a reception of
course following afterwards chance to
chat with our denied speaker talker
bagging though but first I'm going to
sit down and have dr. Paul shank come up
he's one of our scientists you've heard
speak about Pluto and Dawn and he's
gonna tell us more about tonight's
speaker welcome welcome
talk about Jupiter today and I'm going
to introduce dr. friend Bagon L who I've
known since I think Dirk was young I
think and I asked her over dinner to
tell me what she why me to tell her tell
you about her and this is it grew up in
England came to the US as a graduate
student at MIT for a year but got
involved on Voyager and that was it
okay but there's actually a lot more to
it than that
she's been involved in curtain me if I'm
wrong but I think every spacecraft
mission to the outer solar system since
for synthroid your days which was in the
1980s I don't think that that we've
actually missed any of those and she's
been studying the small microscopic
particles that get blown off by the Sun
and sweep through the solar systems
known as the solar wind and how they
interact and populate the magnetic
fields of the giant planets and and
she's been working on Voyager she worked
on Galileo which orbited Jupiter Cassini
which is still orbiting Saturn and just
this past year new horizons at Pluto
which has some interesting things that
we discovered there as well and now on
Juno because she's going to tell us
about what Juno is going to do at
Jupiter
and she's actually complained to me that
she helps write a book about Jupiter
which was published in 2004 ironically
called Jupiter and she's not going to
have to rewrite that book because of the
discoveries of Juno so I give you friend
I go okay thank you very much indeed
and it's really exciting to have flown
past Pluto wasn't luto cool the new your
eyes and stuff absolutely amazing stuff
to go from Pluto last July to flying
past going into orbit we hope around
Jupiter on the 4th of July with the Juno
mission so I need to tell you about the
Juno mission what we hope to do and why
it's important for solar system
exploration and in fact understanding
how the solar system formed how
different solar systems form maybe
around other stars and so on so let's
start off with our usual idea of what
this whole system big planets are
involved Jupiter Saturn Uranus and
Neptune are two pairs Jupiter and Saturn
ten times the size of the earth hundreds
of 300 times the mass and then urines
and Neptune are more a few times earth
masses 20 or so earth mass isn't about
few times the size of thing but we're
really interested in Jupiter the biggest
one three hundred times the mass the
earth and how it forms it plays a role
in the formation of the solar system
it's the big planet of this whole system
so these are pictures that were taken by
Voyager and by Cassini improved cameras
over time and Cassini was able to take a
really fantastic view and put together
once we map it out in the latitude and
longitude scheme we can then look at the
movie showing the clouds moving back and
forth and you can see the east and west
flowing winds the white ones going one
way the red ones going the other and of
course the Great Red Spot which has been
observed since we've
us put up telescopes to look at the sky
since Galileo's time we know that the
Great Red Spot has been there so what
are we really looking at well what we're
looking at is the outermost layers of a
planet and the the white clouds we're
seeing reflected sunlight all at all
colors of the spectrum and when we're
looking at the red ones we're seeing
clouds that tend to absorb in a blue
part of the spectrum and reflect red and
we think it's sulfur that's causing most
of that reddening I of those clouds we
believe there are three layers of plants
and outermost layer that's our ammonia
ammonia particles that form clouds the
middle one is a mixture of ammonia and
sulfur ammonia hydrogen sulfide and the
bottom one we believe we can't see it is
water deeper down now what are we really
looking at well what we're really
looking at is a big gas bag this is a
gassy planet it doesn't have a surface
and what we're looking at is the way
things work at the giant planets and a
lot of the planets around other stars is
that if you add gas and you add more gas
it's a bit like a stack of pillows and
you keep you've got mass pushing down so
you have more pillows you've got more
mass so at the bottom you've got more
deeply compressed material and then less
compressed up here so pressure is
increasing with depth just as our
atmosphere is is down a sea level versus
up at the top of Everest you've got much
less pressure at the top of Everest it's
the same sort of thing and this is
really all just gravity pulling down on
gas as gravity pulls down on pillows so
if you add more pillows to your pile
what happens is it doesn't increase in
height by one pillows worth it gets
compressed down and so what we find with
the giant planets is that they end up
Jupiter and Saturn being more or less
the same size as our many of the planets
around
the stars you're just adding more
material and they get more and more
dense inside and so Jupiter is three
times the mass of Saturn but it's more
or less the same size there's not a lot
of difference in size okay so let's
think about the outer layers what we're
seeing well we see have the same sort of
situation as we have here on earth when
we have gas is rising up they condense
but because spin the Jupiter spins every
10 hours rotation plays a major role
Coriolis force is important and you end
up turning that rising motion into
east-west winds and so we have these
belts and zones as they called when you
look at the planet so if you look with
the telescope and I encourage you when
you to go out now is a very good time we
have Jupiter high in the sky when it's
not cloudy you can see it clearly and
you can see with a a relatively small
telescope the the belts and zones now if
you look with an infrared telescope you
can look at the hotter parts deeper down
believe but between the clouds and the
colder parts look black higher up so
it's sort of inverse of what you see in
the visible part of the spectrum what
you're seeing in the infrared is the
internal glow trying to get out and this
will be an important thing when we start
talking about Juno science ok so we have
these white ammonia clouds ammonia Hydra
sulfide clouds of the yellow ones below
and of course the Great Red Spot is a
big storm system that we've been
observing since voyager time in detail
and seeing its swirling around it's a
high pressure system in the southern
hemisphere we can take our observations
of Cassini taking the equatorial plane
and project them onto the pole and we
see these belts and zones consider it
continuing up towards the poles but we
don't really don't have information in
the actual polar region this movie is
kind of cool and it shows you these
belts and zones continue in quite a long
way up but we don't really know if they
continue to the very polar region
because we haven't
the polls now we wanted to know what was
inside Jupiter very important for
understanding formation of the solar
system as I said and we wanted to know
what the cloud system was like so the
Galileo mission sent a probe into the
atmosphere in 1995 and so what we
expected to see with this probe went in
we're measuring all the weather
parameters was we'd expect to see these
three layers of clouds as it went in but
what we actually saw was very little
virtually no clouds at all
so what mirth was going on well what was
happening was in fact that where the
probe went in was between luck would
have it it went between these cloud
layers right and so when we look at
where it went in using the infrared an
infrared telescope this doesn't seem to
have come out very well but it it went
in was are actually in a hot zone which
was a downdraft region where we were
between the clouds okay so why do we
really care about the clouds of Jupiter
well it has to do with understanding how
the solar system formed from a big cloud
of gas material can't condense that form
the core of the planet and then gasping
entrained into Jupiter and so what we
thought was that when you look at the
abundance of elements the main principle
highly abundant elements we expected
that the the inert gases helium neon
argon Krypton and xenon what we see is
what they're all enhanced by about a
factor of three over the Sun and the
solar abundance and so we suggested that
that was the sort of abundance of
material that was being pulled in to
make most of Jupiter but then when we
look at carbon and nitrogen the Earth's
consistent sulphur consistent but we
didn't see any water so if you take
oxygen
third most abundant element in the
universe you'd expect there to be a lot
of it in Jupiter you add oxygen to
hydrogen the most abundant element you
get water right so if we don't see water
clouds where is the oxygen and what's
going wrong with our theory of the
origin of this whole system so to keep
things simple astronomers have this
periodic table and hydrogen helium and
oxygen is number three and and as I say
if we can't get oxygen right then we
really don't understand how the
formation the solar system was so um
this is our idea we think that as this
gas collapsed
it was hot inside close to the star and
the low abundance let me just go back to
that table you can see the things that
make up rocks are very low abundance and
so rocks and iron we know then that we
make small rocky planets in the in the
solar system and we make large giant
planets that form outside this snow line
where we think large snowballs
accumulated of the material that
condense the water bit of ammonia
methane nitrogen Co but mostly water
form these huge snowballs once you get a
snowball that's about 15-20 Earth masses
you start pulling in the gases that are
there particularly hydrogen and you make
big gas giant okay so this is our idea
that we've had for many decades now how
the solar system formed but if we go to
Jupiter and find there's no water or
we're lacking water what on earth is
going on what is wrong with our theory
of how gas giants form so this was a
motivation to go back and you might say
well let's just send a whole bunch more
probes and maybe end up going into the
wrong place in which case you're stuck
in here well you know
you go to the wrong place or or or did
you just are are theories wrong so what
we decided to do was to find a new
approach we were going to go and look
for water but not by sending probes in
by sending a spacecraft that gets really
close I'll show you in a bit how we're
going to measure it so it turns out that
we though were not it wasn't enough
plutonium-238 around to make
radioisotope thermoelectric generators
we had to come up with a new way of
powering our spacecraft and we decided
to use solar panels and these are the
large solar panels that we have on Juno
and so this is our spacecraft here is a
human right down here at the end of the
solar panel this is a sixty foot
diameter okay really large solar panels
that provide about 200 watts of power
out at Jupiter where of course the Sun
is about 25 times weaker than his here
at the earth but that should be enough
to power our spacecraft our spacecraft
has a variety of instruments a
magnetometer the end of the boom a
couple of energetic particle instruments
Jade and Jedi we have a wave instrument
that will measure plasma and radio waves
a couple of spectrometers a UV
spectrometer an infrared spectrometer
and we have a microwave instrument that
will measure microwaves and that's going
to be very important for measuring water
gravity science will be using the radio
antenna to measure motions of the
spacecraft that tells us about gravity
of Jupiter oh and yeah we've got a
little camera yeah threw that on umm
it's a PR instrument so you know in in
in space exploration business as you
probably know the cameras rule because
the public relations and everybody wants
to see the pictures
what's going on Mars the rover getting
stuck in the sand those of us who
measured charged particles and magnetic
fields and gravity ways you know we have
to put up with a spacecraft being pushed
around to take all the pictures and
we're if we're lucky
please can we make a measurement please
can you make a measurement in the
cameras let us make a measurement
occasionally I'm on this spacecraft we
will tell the cameras where they're
pointing and what they're gonna see and
we will make our measurements and if
they're lucky they will get a picture to
show the bottom are you exaggerate of
course but um it will take some really
cool things but ah it's a spinning
spacecraft and so you can imagine the
spacecraft that is spinning every 30
seconds you're not going to be able to
turn and move and target things very
easily but there will be some choice
about what we can observe okay we'll
come back to the camera later okay in
the meantime in order to make the
measurements that we want to make we
have to get very close to the spacecraft
sorry we have to get very close to
Jupiter to thee to the planet and that
means we have to go into the radiation
environment which I'll show you in a
minute and so when we built the
spacecraft we put all the electronics or
most of the app trunks that could inside
a vault with a really thick titanium
encasing to protect it because this is
what we are going to have to do so his
Jupiter and around it there are very
strong radiation belts these are like
the Van Allen belts of the earth but
more intense more dangerous these are 10
MeV electrons which are very energetic
penetrating charged particles that will
if they go through your electronics or
through the skin of a human for that
matter we're not taking humans here by
the way um but the electronics get very
easily get damaged by these charged
particles and
so we are trying to protect the
spacecraft we've designed our spacecraft
our mission our orbit to go over the
poles duck under the radiation belts
above the clouds and then back out again
and it takes about it takes about two
hours to go from pole to pole it's
moving at 60 kilometers a second it's
really moving fast over here and then it
spends two weeks out here sending the
data back to the earth and then we do it
again and so on so that's great very
well-designed trajectory the only
problem is Jupiter spins every 10 hours
so rotation is really important and so
it's actually much fatter at the equator
than the poles back 10% so there's some
bladeless this flattening this
equatorial bulge
causes the orbit to go from here in the
equator starting dipping down and after
16 orbits it's thick down here and by
thirty orbits it's dipped all the way
down and so you can see after a dozen
two dozen maybe three dozen orbits we're
going to be going right through the
middle of this lethal radiation
environment so we don't know how long
this spacecraft will survive if we only
get 10 orbits we'll learn a huge amount
of that Jupiter boy we're hoping that we
will go for 30 or so orbits and survive
but we just don't know it's a new
environment new world we just don't know
what that will be for us baseball okay
so that's the plan and what we're going
to do is we're going to map out the
planet we're going to design our orbit
so that we scan different regions we
come back at different longitudes and
measure the environment around Jupiter
at these different wattages are we going
to do this in a variety of ways the
first thing we want to do is to measure
the distribution of mass inside Jupiter
and to do that we want to measure the
gravity now this is done a lot with
various space missions and the beam
mission say that say you have a planet
that has
Rock and he have a big mountain here if
you have a spacecraft flying over that
mountain the gravity will be put
stronger over the mountain if you like
pulling the pendulum or pulling on the
spacecraft as it goes over the mountain
and so we can map out the gravity as
we've done for the earth in gory detail
really quite impressive what V the grey
spacecraft has done the earth and the
Grail spacecraft has done on the moon
measuring the distribution of mass you
can see the impact craters and how this
affects the mass on the moon now the way
we're going to do this is as follows we
use the radio antenna that has a
transmission back to the earth and this
the spacecraft goes along if there's a
uniform gravity the spacecraft is not
very much perturbed on its orbit but if
there's a gravity inside that perturbs a
detailed structure it'll make the
spacecraft wobble and there will be a
detectable Doppler shift in their radio
signal that's been sent back to the
earth and so we use this Doppler shift
to tell us about the gravity the
distribution of mass inside the way we
do this in space science is to measure
the power as a function which is a
vertical scale here versus complexity a
higher the this number is along here the
greater the degree of complexity so the
low order structure that happens over
most of the planet will have a low
number but if there's a small scale
structure that happens at one region or
another it'll be at a higher number here
so for Jupiter
we've only measured the very low order
at very high power structure and what we
hope to do is to measure and this red
line is just a a wishful thinking of the
theorist that says that we'll be able to
measure the power a very high order
which will give us the complexity the
detail distribution of mass inside
Jupiter and this will tell us where the
mass is and what's going on inside
okay so what we think is inside these
gas bags Jupiter and the other giant
planets is we have this idea there might
be a core deep inside we have an idea
that um we have a hydrogen above that
and and it much denser deeper down so um
I'm showing that I've these figures are
being and maybe this is a translation
with this projector but let me talk you
through what we're seeing here the
density here is low up high and compared
with water so this is about the density
of water one we get down to a density
about of rocks and really dense metals
deep down inside and this is because of
the gravity pulling down on the gas and
the temperature rises up to about five
times four to four to five times the
temperature of the surface of the Sun so
it's really hot inside because of the
high pressure now the temp the pressures
are very high in fact the number that
you can't read here is a hundred million
times the atmosphere of the earth so
what are these pressures actually mean
okay
sorry in attorney what that means when
we talk about pressure we're talking
about weight or mass being pulled by
gravity and I have a certain weight or
than I should have but I have a certain
weight and I can feel the force of
gravity through my feet and there's a
pressure through my feet and I can
calculate that pressure as my mass times
the force of gravity per unit area of my
feet okay so what happens to the
pressure pressure is force per unit area
if I stand on one foot what happens the
pressure does it go up or down by a
factor of right I've harped the area and
so I've increased double the pressure
okay so in order to talk about the
pressure of the gas in this room you
have to
have five people standing on my
shoulders above me and all that weight
coming through my feet that is the
pressure in this room you can do the
math to check it doesn't seem credible
because we're so used to it right we're
used to that pressure but if you were
out in space and your spacesuit was
evacuated you would suddenly realize
yeah you used to a lot of pressure that
is going away okay so that's the
pressure in this room what about the
pressure deep down inside Jupiter what's
it like there well we can't use humans
so how about elephants okay so let's
have an elephant okay let's have an
elephant standing on one foot no no no
you need a thousand elephants standing
on top of each other and the bottom
elephants standing on one foot on a
stiletto heel and then you begin to get
the right sort of pressures right sort
of a something like 50 to 100 million
bars times the pressure in this room so
we don't really know how hydrogen
behaves at those pressures I mean we
can't write a proposal to NSF saying
could I have a thousand elephants I want
them to stand on each other with the
bottom on us over here even Lawrence
Livermore and the places that study
hydrogen and that high-pressure G maybe
related to hydrogen bombs maybe I mean I
don't know but I would guess that maybe
know about this stuff they don't get to
these pressures okay and so we are sort
of making it up we don't really know
we're working on a realm but we do not
have experimental evidence and so we
have to rely on theorists that tell us
what happens when you take hydrogen to
such high pressures now we have taken
hydrogen to a couple million at couple
mega bars a couple million times the
pressure in this room and what we know
is that molecular hydrogen
which is two protons and two electrons
right in a molecule what happens is when
you get to very high pressure you break
those apart and the protons and the
electrons can move around separately
okay so once you allow positively
charged protons to move around
negatively charged electrons to move
around you can now drive electrical
currents through that fluid okay and so
we move to hydrogen turns into what we
call a metallic phase where it becomes
electrically conducting and so in many
ways deep inside Jupiter who think this
transition happens somewhere about 80
percent of the radius of Jupiter much
deeper down in Saturn because of the
lower mass it turns into something like
liquid mercury that you have in your
thermometers like so a liquid metallic
material at fairly high pressures so
this is the story and this is the
cartoon that we started off when we
launched Juno and we thought well we'll
look inside are we gonna see a core
inside of rock and maybe ice materials
and with the hydrogen around the outside
but you know what's happened is the
current idea is that in the time since
we launched in 2011 now the theorists
are beginning to say yes but when I do
my quantum mechanical models and you
know I nearly put it on a German accent
because it turns out the guy he does
this is a quantum mechanics guys it's
German and I think a lot of us think of
19th century physics and the early
quantum mechanical people having German
accents so I can't help thinking in the
German accent when I talk about this but
we have quantum mechanical models of of
hydrogen at these very high pressures
and we thought originally about you know
that there would be a core inside of
those heavier elements those bits of
iron and nickel and and sulfur and and
so on oxygen and carbon deep inside
but they're now saying that once you get
to these high pressures
you just have metallic hydrogen and all
of the heavier elements become dissolved
in that liquid metallic hydrogen and
they will be just be sitting around as
separate elements and it would be all
mixed up and you won't have a special
core and distinct core so this is the
sort of picture we're thinking about now
is it like this where you have something
a bit more like a easter egg where
you've got multiple layers or do you
have a more mixed up I've got to think
of the name of the chocolate there's
probably some kind of chocolate that I
can describe that looks like this inside
but you know is it more mixed up with
the heavy elements being mixed up rather
than a concentration deep inside so this
is what we're trying to sort out by
measuring the magnetic sorry measuring
the gravity field will tell us about the
distribution of mass inside and maybe
the flows inside that's why we want to
measure the gravity the other thing we
want to measure is the magnetic field
because this liquid metallic region will
be turning over and we'll have a dynamo
and if we expect there to be a strong
magnetic field inside and what we really
want to do by flying over and through
this environment is that is to measure
the magnetic field of Jupiter we have
some idea about the dynamo structure
inside but we really don't know what the
flows are and what are the flows that
might be driving it this is from a model
but it's just the outer layers what's it
really like deeper down so we're going
to do the same sort of thing with the
magnetic field as we do with the gravity
field measure the power as a function of
complexity or scale and what's
interesting is when we do this with the
magnetic field of the earth what we see
is that we can measure this out to quite
high order something like about 11 or 12
and we but the problem then is because
the earth has a cross that can be
magnetized the rocks of the outer layers
of the earth can be magnetized the outer
of the most detail
structure that we have a higher order
the higher level of complexity in the
magnetic field of the earth is all in
the rocks in the outer layers it's got
nothing to do with the internal Dynamo
so once we look to higher order
structure we're not learning anything
about the Dynamo with Jupiter because we
don't have a crust we don't have rocks
that are magnetized and the outer layer
we hope that we will continue measuring
the complexity to quite high order maybe
as high as 20 or so but will tell us
about the Dynamo will perhaps know more
about the Dynamo of Jupiter than we do
about the earth in terms of degree of
complexity inside we really don't know
what it will be like and the penny on
the scale of that metallic region we
don't know what the extent is of the
Dynamo how far out it goes so this is
what we want to do
measuring we're gonna fly over and get a
sense of is the flow inside sort of
cylinders which is one theory or is it
that the flow inside is in fact more
turbulent more like the sun's dynamo
where everything is turning over in
small structures so we hope to find out
what it's really like
by measuring the magnetic field and the
gravity okay so that's the deep interior
what about the outer layers what about
the water what are we going to do there
well we know in the outer layers we have
these layers of cloud we want to measure
the clouds and the distribution of water
and ammonia and we decided that instead
of sending more probes what we would do
is to measure the microwaves that come
from the inside now you all know that
microwaves are absorbed by water that's
how you heat up your cup of tea in in
the microwave oven right you put your
water in there you turn it on and the
water heats up it's the same sort of
thing we think has happening
the deep interior of Jupiter is really
hot it's retained heat of formation and
that heat leaks out and we want to
measure that we want to measure the
amount that's absorbed by the water
clouds and the ammonia clouds and so
we're going to measure at
different wavelengths of microwaves
between one and point three centimeters
and 50 centimeter so wavelength sort of
in this range and this will let us get a
measure of the distribution of water so
we have these six different microwave
antennas the spacecraft's going to be
flying over Jupiter spinning and as it
spins over as it goes over the planet we
will be able to measure the outcoming
radiation in microwave and measure at
different wavelengths and will tell us
what the distribution is of water and
ammonia not only as a function of depth
but we also will be flying over in these
strips and measuring the distribution
relative to the clouds and so how much
is what is the distribution of water and
ammonia as a function of both height and
latitude and longitude and so this will
help us get a sense of how much water is
there inside of Jupiter and how is it
distributed okay so that's what we're
going to do to give us the distribution
of water now we chose this orbit to
measure the gravity field for magnetic
fields and the microwaves to give us the
water and ammonia but because we happen
to be flying over the poles we're going
to be able to fly over a unique region
which we have never flown before and
that's the magnetic field region the
magnetosphere of jupiter Jupiter's
magnetosphere is huge for comparison
here is the Earth's magnetosphere the
whole maggie's they would fit within the
planet Jupiter whereas with the Jovian
system where the field is much much
stronger we have a region this bubble
this magnetic bubble around Jupiter that
extends up to a hundred times in the
direction towards the Sun and extends in
the long tail away from the Sun all the
way out past the orbit of Saturn 9au so
this is a really long tadpole like thing
a large volume it's rote dominated by
the rotation of Jupiter and it's filled
up with sulfur and oxygen becomes a meal
now as Paul shank here well I think
agree EEO is one of the most weirdest
and exciting moons that we have in the
solar system it is volcanic as Voyager
found out it has plumes of sulfur sulfur
dioxide spewing out the hot region shown
in this infrared image this
high-resolution region shows they're up
to 300 different hot volcanic regions we
look a few months apart with the Galileo
cameras and we see there's a complete
area not quite as big as Texas but as
big as regular states in the united
states like Colorado that that I covered
with new lava every few months or so and
so we know that this is a very active
region it's the most volcanic object in
our solar system 100 times more volcanic
than yes and so it's very active all the
water has been removed and the sulfur
and oxygen that comes spewing out
actually becomes escapes when the planet
becomes ionized and trapped in the
magnetic field of Jupiter and you get
this big torus that extends out in fact
beyond interacting with Europa and
Callisto to some extent but this is a
ultraviolet glowing doughnut of ionized
gases that are trapped in the magnetic
field the magnetic field like the earth
wobbles with a 10 degree tilt and so you
end up with this wobbling around because
of the tilt of the magnetic field so
this ton a second of material that comes
romão fills out this magnetosphere and
it becomes accelerated in the magnetic
field and what happens is those
particles eventually come bombarding
down onto the atmosphere of Jupiter and
produces the Aurora
and if we look at Hubble Space Telescope
data and I just got to show you some of
these fantastic data from Hubble where
we have these are like RAW images or
semi raw images but I think you get to
see the dynamic nature of this Aurora
you have a fairly static ring of Aurora
and then in the center you have these
bright spots which we don't really
understand why these are coming in going
occasionally and then we also see you
will see a spot an a a path let's wait
for the right one to happen and here it
comes coming around you can see there it
is up here you can see here it is down
here and um it's a spot there actually a
series of spots and a weight behind and
these Aurora's are associated with the
moons Io Europa and Ganymede been
looking for Callisto but it's harder to
find ah and these are electrical
currents that are produced in the
interaction of the moon with the
magnetic field and the trap plasma those
currents flow along the magnetic field
into Jupiter's atmosphere where they
trigger these Aurora's and generate this
light and there's a lot of power in that
and these are millions of amps currents
that are flowing along the magnetic
field into the planet so this is a very
dynamic environment we're going to be
flying flying with the Juno spacecraft
right over this region and so what we'll
be doing is we'll be flying over we'll
be measuring the charged particles that
are streaming along the magnetic field
we'll be looking at the Aurora and we'll
be trying to understand what is the
connection between the particle
environment the magnetic field
environment and the Aurora that we're
seeing below
we've never flown through this region
before at Jupiter we have a good sense
of what happens at earth we can test our
ideas of the physics of how this works
at Earth and apply it to Jupiter is it
anything like the same or
it totally different so it'll be very
important physics experiment as well as
understanding all this energy that gets
poured into the apparatus fear of
Jupiter so that'll be a very dramatic
time for us to fly through this region
okay
time to show you the spacecraft they
actually let me go inside and have a
look someone was I had to dress up like
this so that we keep the spacecraft very
clean and and don't get any human dirt
onto the spacecraft you see the
engineers are all dressed up like that -
someone stood next to me I'm not an
experimentalist so they were really
watching me very carefully
but I just went in and had my picture
taken next to the spacecraft I couldn't
resist it okay so let's look at the
time-lapse movie and they put it off the
Busic and then you look at the time
lapse that it goes on it's great so the
engine is they they put a piece on they
did a little about with it measure it
take it off again fiddle with it more
breathe back on again little with it put
it back on i'm trivializing it this is a
lot of work to make this spacecraft work
right you know it's a lot of work and it
takes months in fact the probably is put
this together
and you know it's a lot of work yeah
with a lot of people putting it together
and you you realize yeah a lot of people
put a lot of time and energy probably
about a thousand people participated
last night one of these relatively small
science space time to put this together
and are they happy tea breaks they go
awkward you are they're working pretty
hard it's kind of cool
okay time for launch let's let's skip
ahead a little bit because that movie
goes on quite a long time um even with
the timers so the spacecraft's all put
together we put it inside slap a fairing
on put the stickers on take it ahead of
the Cape that's the most important bit
right you're putting these stickers on
I'll take it out and cake put on the top
and that was five and then we roll it
out and we get the team in front take
the pictures okay but um
Lockheed Martin put two cameras on the
spacecraft somewhere around here and so
I'm going to show you a launch movie and
what you will see is looking down at
Kate's okay welcome everybody glad you
could make it this evening
quick question is anybody exceptionally
warm and don't look at me cuz I I just
sweat okay we would see if we can turn
down a little bit it's kind of stuffy in
here with all these people this is
fantastic
glad you're here my name is Andy sander
as so you may know you're at the lunar
and planetary Institute here in Houston
and tonight is our this is our fourth
presentation in our current public
lecture series exploiting the solar
system today and tomorrow our little
final and fifth presentation will be on
june 2nd with dr. Alan Tremont from here
at LTI giving us an update on where
things are at with the Curiosity rover
on Mars and he's going to talk about the
tires for the wheels I guess so
so if you've been okay welcome everybody
glad you could make it this evening
quick question is anybody exceptionally
warm and don't look at me because I I
just sweat okay let's see if we can turn
down a little bit it's kind of stuffy in
here with all these people this is
fantastic
glad you're here my name is Andy sander
as so you may know you're at the lunar
and planetary Institute here in Houston
and tonight is our this is our fourth
presentation in our current public
lecture series exploring the solar
system today and tomorrow our little
final and fifth presentation will be on
june 2nd with dr. Alan Tremont from here
at LTI giving us an update on where
things are at with the Curiosity rover
on Mars and he's going to talk about the
tires for the wheels I guess so so if
you've been hearing about that you're
gonna you're gonna hear some more of
that at that time a couple of things you
may have seen on here I want to just
kind of reiterate on May 9th there's a
transit of mercury which means I'm gonna
see mercury going across the face of the
Sun slowly but you can see it we're
gonna have a telescope set up at the
Freeman Branch Library from 10:00 to
noon that day as long as it's not cloudy
so you're welcome to come out and see
the transit and it's happening it's kind
of a cool cool little thing to see but
you get to see the Sun up close bring
your sunglasses one of our scientists
David Crane who you've probably heard
speak before he'll be giving two
presentations at the Houston Museum of
Natural Science May 24th and June 30th
as part of their lecture series out
there so if you want to there the flyer
fed out front if you want to go see that
he's a good presenter too you gotta buy
tickets but that's their thing not ours
but this would be good talks if you want
to be heard of ones about the lunar
exploration then everyone's talking
about the threat of asteroid impacts so
a fun one and then a scary one to
balance it out and on the flyer it says
that it'll be in the planetarium and
that's true if you look at it online it
says it'll be in there big see
we just found out recently gonna do it
in the planetarium because they just
overhauled the system and got those nice
great new system in there so they're
gonna do it there it's dead at the end
of tonight's presentation the course
will have a Q&A session you can ask your
questions if you have it if you do
please raise your hand will be two of us
going up and down the aisles there with
a microphone best so of course we all
can hear it slower also recording
we're also streaming live on Ustream
which did the last presentation so again
manners
I beg now and of course whoa just do
this there's a reception of course
following afterwards a chance to chat
with our design speaker doctor bagging
though way getting that so let me just
show you um the flyby we we actually
tested a lot of stuff including going
through safe English it's good that we
do it at Earth not at Jupiter um
recovered learnt a lot of lessons we we
took a lot of pictures this was a view
looking up but you could see Juno flying
by and but the coolest thing was that we
got all of these amateur astronomers to
dit da da send their radio signal up to
to Juno saying hi Juno and Juno measured
it and sent it back so it's kind of cool
that we actually communicating with the
spacecraft so this is what we're doing
we're on approach where where the sun's
over here on the right and so as of
today we're somewhere around here okay
and we're on our way to rendezvous with
Jupiter we are going to come in pretty
close and then we'll we'll buy the
engines on the fourth of July and then
go into what we going to do is this is
looking from the Sun or from the earth
will come in to approach will do 253 day
capture orbits and that'll give us a
chance to do a couple of flybys into
that really hazardous environment close
to Jupiter get a
for it check that we Juneau is doing
okay and can survive through that
environment we'll learn how the system
works and so on and then we'll get into
our will do a period reduction maneuver
and then go into these close in every
two weeks and you know we don't know how
long will last we hope to last the 30
orbits but like I said if we only get
ten will we'll learn a huge amount about
the interior of Jupiter magnetic field
of Jupiter the distribution of water
as well as the aurora but okay the
cameras so we're going to do something
really cool this is really is an
education public outreach camera we will
hope to do some science but what we're
doing is we're going to put off on this
website a bunch of choices of where
we're going to take the data and bring
the data down with the camera and people
can go and vote on what their purposes
so we will go and look at the targets if
you want the red spot you want to look
at a little brown spot you want to look
at a big cloud that's going by you
whatever whatever you want to look at
but the other thing that's really cool
is that there are already hundreds of
pictures of Jupiter that have been taken
by amateur astronomers that are already
up on this website and we're encouraging
people who are interested in in doing
data processing a lot of image
processing people in the amateur
astronomy community in fact I'm
reluctant to use the word amateur
because these people are very proficient
and very capable and it'll be great to
combine the observations up close that
we take with Juno with the ones that
they're taking from Earth of
observations and so this will be an
exciting new way of doing science and
involving the public in our in the
science that they're doing so we're on
our way we've only got a few months to
go we're really looking forward to
understanding what's inside where the
water is are our theories of solar
system formation I have to be thrown out
of the window and start all over again
or
is the vmas war that we think that's
their what is the distribution of
material like inside are the
quantum-mechanical guys right and that
there's heavy elements have dissolved in
the hydrogen and spread out or do we
have a distinct core as shown by this
cartoon thank you very much
okay I'm having to take the question
somebody's gonna run around with the
microphone is that right okay well this
woman here in the red hang on a second
you wait for microphone yeah thank you
thank you for your presentation this on
yep so the orbit goes around and it
precesses into the deeper part
how many orbits before it precesses back
out into the slot excellent excellent
so I showed you this idea that if
Jupiter's here and we have go-fast over
the poles and then it goes out here and
that this orbit begins to press s like
this indeed as you're guessing it will
in fact come around and come out the
other side
well it's about a degree per orbit and
so ninety orbits to go vertical 180 to
come out the other side so chances of
surviving out a pretty slim the other
problem is we only have money for 36
orbits so first we have to survive then
we have to ask for money so but we are
planning to go into at the end into an
orbit that would eventually degrade so
what we do is we bring down the closest
approach a little bit so that after some
time and we're thinking thousands of
years it will eventually go into Jupiter
because it must not hit Europa right we
all know why because we were told all
this was except for your over yeah
I have no landings well right so the
thing of course is that we but we did
good look into the planetary protection
and the speed that Juno is moving at if
it did hit Europa it would basically
vaporize so I'm not too worried it is
not carrying plutonium so it wouldn't
sink through the eye so the chance
it actually it's pretty unlikely that we
will hit your Oprah or anything will
happen it's an extremely low probability
but yes there's a question over here do
you want to who's got the Leslie oh
maybe I can do this yeah let me give
that to you thank you for the
presentation you alluded to the idea
that Jupiter formed in the outer solar
system but if I understand correctly the
nice theory would imply that it
propelled itself out there is there
something you can determine from the
data that will support a review the nice
theory okay I'll repeat that question so
um the picture I showed of the solar
system formation with that big disc and
the snow line and Jupiter forming beyond
the snow line and so on um busy this
sort of a few decades ago and things
have evolved in our ideas of solar
system formation and um there's still
the idea that Jupiter and Saturn the
next part of it was to say children's
happen form where they are more or less
where they are but you're honest and
Neptune formed in close and then got
kicked out and I think that's now
gaining a lot of strength and maybe that
new planet X that's been discovered by
the Caltech guys could indeed be a third
Neptune that was sort of yours and that
universe kicked out so the most recent
theory called the grand tack says what
if Jupiter formed probably where it is
now but it had an excursion going
inwards and then went further out again
and I don't fully understand I've heard
one or two presentations on this um the
question is would we be able to tell
from just looking at the interior of
Jupiter I don't think that we can take
on the thousands of computer models that
people have done and say it's this one
not that one or that one
right but what we will be able to do is
to say
this class is clearly not going to work
in this class has a hope of working from
looking at the distribution of water at
least that's my expectation it could be
completely wrong if we don't find any
water and there's no oxygen inside
Jupiter then you know I really don't
know where we go but I mean getting some
sense of that number will constrain it
also getting I think some of the other
elements will be important because it's
not as simple as that original picture
people are now talking about pulling in
different parts of the periodic table in
different ways and I think we'll build
up a much better we'll have a much
better knowledge after but I doubt we'll
pin down it'll be the last word sources
and formation but it's all getting very
interesting it's not as simple as we
thought it was you know a few decades
ago
another question okay
you only give this man a microphone I
can repeat it yes right so sad man as
many of you know has been I had a
spacecraft called Cassini that's been in
orbit around Saturn since 2004 did I get
that date right and so it's a long time
now I mean that's 12 years now and in
the next two years um they've changed
the orbit of Cassini so that it will fly
similarly over the poles again and
through close to the equator I think
it's going to go you know perilously
close to that ring plane or those rings
this Jupiter we have to worry too much
about the Rings the ring plane region um
and we'll do similar measurements of the
deep interior with the gravity
measurements of magnetic field
measurements as well as flying through
the polar regions of the aurora and so
it's going to be extremely valuable to
compare these two giant planets one
that's a hundred masses at Saturn on one
that's 320 Earth Mars Jupiter and see
what the relative comparison is about
there in
we do know that their interiors are
different but how different they are
it's going to be very interesting and
make these comparisons so comparative
planetology is always the game of plants
for science and it's going to be great
that they're going to have these two
happening in the same epoch so yeah it's
our next couple years are gonna be
really interesting for giant planets
okay
just quickly since you only have funding
for 30 orbits but our electronics do
marvelous things are you gonna try to
get funding for the one hundred and
eighty first orbit to see if it just
might wake up again let's get let's
first get into orbit Jo I know do it one
step at a time
um this young woman here how to how to
hand up
- oh I'm Louise I'm author the speed of
light and what's the latest thinking on
why Jupiter gives off so much radiation
that's so much more than receiving the
Sun okay and how can I keep spinning so
fast after billions of years so so we
haven't be careful we use the word
radiation when all of what I've been
talking about so far has been about
particles protons electrons and ionized
sulphur and oxygen that's trapped in the
magnetic field but I also mentioned the
fact that it's hot inside and it's
radiating out and that radiation is in
the form of photons and I was talking
about microwave photons coming from the
in Syria and infrared photons coming
from the interior and so that is the
heat that comes from the interior and in
fact Jupiter radiates two-and-a-half
times for your amount of energy that it
gets from the Sun out in the form of
heat and so it's hot inside and the main
reason why it's hot inside is because of
the heat of formation you take 320
masses the earth masses and you pull
that all together that's a huge amount
of gravitational potential energy that
you convert into heat and it takes a
long time
to cool off the way I described this to
mine for astronomy students says it's a
bit like Jupiter being a big fat baked
potato and the earth being P and arms
about the right scale in terms of size
but of course what you're interested in
is the volume to surface area ratio and
that really scales with the size so when
it's big it retains all its heat remains
hot for a long time like a big fat baked
potato and so Jupiter which is the big
fat baked potato of course retains all
its heat inside and gains extra heat
when it forms and it and keeps it for a
lot longer and so it's really just heat
of formation as well as a little bit of
radioactivity and differentiation and so
on but it's mostly the fact that it's
big the means it radiates a lot in the
form of heat yes yeah you can do fairly
straightforward calculations of for
doing that and it's just left over from
formation I mean there's still some heat
of differentiation and radioactivity
with mild mild competitive formation why
is it spinning well when it collapsed it
conserved angular momentum and kept kept
spinning and it has a lot of spin
momentum there's not a lot to slow it
down it's not interacting with other
objects it's hard for other objects that
are not anything like as massive is it
to have talks on it so there is a little
bit of interactions gravity between the
moons and Jupiter that is slowing it
down a little bit but it's pretty slow
it's got a lot of angular momentum in
that spending big 325 masses yeah yeah
oh look look far away you good yes
I hope so I hope so um you know I given
dozens of public talks related to Pluto
and the enthusiasm is huge I mean I
think it's just suddenly cool what we're
finding I thought it was gonna be really
kind of boring to be really honest video
and then I look at the surface
particularly the geology and I'm going
you know who ordered that it's just
really mind-boggling what we're finding
in sea and I think people really are
inspired and excited and what I would
like to see is that we send robots and
we can get into the robot versus non
robotics and other time but I think what
we should do is send robots off all over
the solar system and then bring all the
data back and then give every kid gloves
and goggles
so they could go and explore our
universe our solar system using the data
from those robots all over space either
you'll be fantastic let's just send
hundreds and hundreds of small sets all
over this whole system and find out
what's out there I think it'd be great
and I think there's some enthusiasm for
that and emissions are getting cheaper
actually we're learning to do things
more affordably so the Juno mission and
the New Horizons missions are part of
the new frontiers line which are about a
billion dollars per so over ten years
that's a cafe latte per taxpayer it's
cheaper than the popcorn you paid for
when you went to see the Martian
let's don't go there I gotta let you do
the control of the questions I'm kind of
following up on that question
you know after Juno does bow out to
radiation after hopefully 30 orbits the
outer solar system kind of will be going
dark for a while so maybe talk about you
know are you concerned about the future
of planetary science with kind of the
scarcity of missions to the outer
planets after do you know I think that
we will go to Europa I that's the next
next one on the docket I think we'll do
that um we've come up with good plans of
how to do that how to do that in a
viable way it's a difficult mission but
I think we all want to know what is
underneath that ice what that black that
brown gunk is is it whale poop you know
we want to know what's that and I think
we can do a viable mission that is
affordable that's that's you know
somewhere between Juno and Cassini maybe
geometric mean of those two we can do it
in a portable way I think that we have
huge capability of doing these things
with robots that are amazing so we just
I'm not so pessimistic I think yes we if
you look at the dates it takes a long
time to get the outer solar system
you've got to be patient but I think
we'll be we'll be at Europa before too
long we'll go to other places don't tote
I want to ask you you saw the Pluto
pictures which are absolutely amazing
right now but do you think we should go
to Pluto again or should we go to eros
or Makemake or Maya what do you think
should go to the other camp about
objects or do you think we should go to
Pluto again what do you think asteroid
belt yeah we going to the asteroid belt
got lots of missions going to the
asteroid belt
Your Honor your is ineptitude absolutely
okay so we're gonna learn about the
giant planets with with Cassini and with
Juno but what about your honest
intention those are very interesting
those things that have a lot of water
inside them we think we know this water
of an ammonia and methane in those they
do not have
like hydrogen inside they do have
magnetic fields so they seem to have
ocean dynamos it's really strange driven
the environment what about those moons
what about Triton there's a whole
business of people now thinking about
well if if Triton is the captured cabin
Bell object and it looks so different
from Pluto what happened to triton that
didn't happen to pluto so there's
there's gonna be a whole bunch of papers
people looking at those maybe paused in
a right half of them we'll find out
what's what's going on so yeah
absolutely I totally agree I think it's
plenty of places we want to go and we'll
go there we'll go there any other
questions or we I'll let you need to mom
with a microphone a real quick question
about the metallic hydrogen ion center
of Jupiter it's in a magnetic
environment with the Sun is that a
potential dynamo that's actually
generating it's a superconductor all
right so is that a dynamo producing
energy actually well what's happening is
that the internal heat is turning it
over and you've got rotation of the spin
and those are the ingredients that you
need to make a magnetic fields and we
know Jupiter has a very strong magnetic
field so it's a magnetic dynamo that
generated in the metallic hydrogen in
the same way the Earth's dynamo is in
the liquid metallic iron that's deep in
the outer core of the earth which has
internal heat turning it over with a bit
of spin and you make a magnetic field um
now I know we need those three
ingredients actually making it work is a
lot harder and our dynamo models of
Helly crew right now but certainly it
seems to be if you have those three
ingredients you do make a magnetic
fields and the details we will learn now
I put this up here because I thought
someone would want to know about the
Great Red Spot do you wanna know about
the Red Spot it's getting smaller isn't
this cool so if you look at the top left
that was the Voyager data it was about
22 degrees of longitude so that's about
three times
size of the earth and it's been getting
smaller
these are Hubble Space Telescope
pictures and Galileo pictures it's
getting smaller and if we project
further what we see is at the time of
Juno it should be somewhere around I
think about 12 to 14 degrees in size so
half what it was at the time of Voyager
and maybe by 2050 it will disappear
whatever you'd come back what do you
think go away I mean we've known it's
been there since the 1600s how can it
disappear in our lifetime we don't well
it must have been back then it must have
been comparable to the Voyager size if
not bigger yeah yeah question tossing
that one out to a layperson it would
seem that using the process you
explained that the mass distribution or
gravitational distribution would look
the same to Juno whether there is a
rocky core very small or a point source
if you will versus distributed matter
throughout how can you tell the
difference well you can you you look at
those it's not spherically symmetric
partly because of the oblate nuts okay
so you're breaking some of the symmetry
there but also we think that the inside
there's actually cylinders right so then
you've got flowing around the outside
which causes and the higher the
structure is well it's not clear how
uniform it is right and then the
question I don't know how well we're
going to determine the actual detailed
variation in density with radius deep
down inside I think mu be able to tell
if there's a distinct discontinuity a
sharp boundary between the core it's
really hard when you've got that large
amount of mass the core is only you know
15 20 earth masses when you've got a 320
math object so it's it's a little hard
to get it super accurately but I think
we'll do enough constraints on the
density and and distribution to
constrain that pretty well the big
question here is knowing the equation of
state the relationship between density
temperature and pressure and that
depends on the material on our
understanding the material and so I
think the physicists will have to work
with the data and and we'll iterate on
this with those quantum mechanical
models and our gentlemen bethey with the
German accents will help us sort this
out and it it science is an iterative
process we won't solve it all in one go
despite what we wrote in the original
proposals NASA
I think dr. Bengal one more time okay
