the search for life in our universe is sort of one
of these intrinsic questions to humanity are we [Music] alone when we look at Europa we see there
are ways to exchange Chemistry Between the space environment in the ocean there are ways to keep
the body warm there are uh sources of chemical energy and heat and all of this has probably
been going on for billions of years so all of a sudden it starts to look like we maybe in our own
solar system have a second implausibly habitable world and you know once you have two in one solar
system then they're probably all over the place historically the NASA have sent three what we call
Flagship missions to the outer solar system three two one we have ignition and as we look at that
tour and our progress through the solar system having uh visited the planets with the Voyager
missions and gone to the Jupiter system with Galileo and the Saturn system with Cassini we're
sort of stopping for a moment and going back to Jupiter and the fourth outer solar system Flagship
Mission Europa Clipper is going to specifically look at one of the largest four moons of Jupiter
Europa to understand if it has the conditions necess necessary for planetary habitability europ
is about the size of our moon and most of its Rock but the entirety of the world is covered in
about 100 kilm of water the top maybe 20 is Frozen as solid ice and then there is a saltwater ocean
we think underneath that surface it has a really unique orbital configuration where it interacts
with the other moons of Jupiter to continuously dissipate frictional Heat at the interior
probably mostly within that icy shell keeping the ocean liquid and warm on Earth we think that
a place life might have originally emerged is it hydrothermal vents on the seafloor where water is
swept underneath and erupts outwards to deposit um new sources of chemical energy uh that sort of
gives you one half of the terminal you need for life and the other half at Europa could be made
by the radiation of Jupiter interacting with ises the real insight it gives you is that you have a
second data point where if if you find a second emergence of life in your own solar system
you can feel pretty confident and satisfied that it's probably everywhere the eura Clipper
spacecraft is this large cylinder with two huge solar panel Wings coming out it's solar panel
Wings span is just over 100 feet uh because the sun is much dimmer at Jupiter than it is at
Earth and so you need a lot more surface area of solar panels on board the spacecraft we have nine
instruments and one experiment that will observe Europa in not only visible light with a narrow
and and wide angle cameras but and infrared and thermal infrared and in the UV and even with an
active Source ice penetrating radar we'll have Inu instruments that can measure the environment
directly we'll have dust analy that can pick up material that's been sputtered off the Surface by
microm meteorite impacts and taste solid material ejected from Europa directly we'll have mass
spectrometer capable of understanding the rarified atmosphere of Europa we'll have uh magnetometer
capable of understanding the size and solinity of europa's ocean by its interaction with Jupiter's
magnetic field but all of this is going to happen from orbit around Jupiter with flybys of Europa
rather than orbit around Europa so we're going to make about 50 flybys of Europa orbiting Jupiter
will come in as close as 25 km each time and the reason we're doing this is Jupiter has a very
strong magnetic field anything coming through the Jovian environment that's a Charged particle
particles from the Sun or the interstellar medium particles erupted off the nearby volcanic moon
IO get trapped and sped up and make intense ionizing radiation and so it's difficult to keep
a spacecraft alive in orbit around Europa because of the radiation environment so we just dip our
toes in and fly out each time we're going to be exploring what processes we think are active in
that ice shell today Central to habitability in our story for Europa is that the salty ocean
interacting with the seaflo could produce a lot of reducing chemistry and so that's chemistry
with electrons to give away and we believe that the radiation environment at the Sur surface
interacting with water and even with sulfur collected like bugs on a windshield from IO as
Europa goes around its orbit could produce strong oxidants so things that want electrons and all
the life that we know of here on Earth uses the transfer of an electron as its most basic energy
source for everything from cell maintenance to mitosis basic functioning and so what we're really
interested in is the place where these oxidants and reductants come together in the two terminals
of the battery close and the surface of Europa is very young so there 's a plausible argument that
these oxidants made on the surface are coming down to the ocean and it's important that we understand
you know the surface geology and land forms and what those tell us about the exchange of material
from the surface to the ocean and the ocean to the surface we're going to be looking for recent
incurrent activity everything from where there might be tectonic faults active on the surface
today to where there might be eruptions of water vapor from water trapped within the ice shell
we're going to be also probing the interior of Europa we have an active Source ice penetrating
radar so we'll be able to image some structures in the ice shell if you look at the surface of
Europa it looks like a yarn ball that's Criss cut by slices there there's all of this tectonic
deformation going on in the surface that pulls apart the ice shell and pushes it together
uh that's Central to Material Exchange and so we're going to be looking at how those features
extend to depth maybe even possibly seeing the ocean through radar on top of that we're going to
be probing the interior of the body by sending a very stable radio signal back to Earth each time
we fly by Europa we can look at the Doppler shift and the radio signal so in the same way a fir
truck driving by you gets really high frequency as it gets close and low frequency as it goes away
as you accelerate flying by youropa you stretch those waves out or compress them and it turns out
if you build up this web of fly eyes and you have all of that Doppler data you can put back really
fine detail about how you accelerate it around Europa and start to understand its gravity
field so then you can start to understand the distribution of mass in the body and recover its
interior structure this is important because the size of the ey shell relative to the ocean and
and the Deep interior structure all contribute to how we understand the world to be habitable
as a system top of all of this we're also going to be looking at the composition of the body
we have a across a variety of wavelengths the ability to compositionally image the surface at
high resolution and so these are like cameras that take pictures of light outside of the visible
spectrum and the light emitted and reflected and transmitted by the material tells you something
about its composition and so we can survey the composition of the surface we'll also be looking
at the temperature of the surface that can tell us what tectonic features might be active or
where shallow subser water or even erupting water we'll be scanning across the entirety of
Europa looking at its Edge for water vapor plumes erupting into space going upward we're going to
be studying the material coming off of Europa both sensing the chemistry of particles ejected
by microm meteorites in sensing the the very tenuous Atmosphere by directly ingesting material
into Mass spectrometers on the spacecraft we'll also be characterizing the magnetic field around
Europa this magnetic field of Jupiter that makes the radiation environment so intense and makes
it difficult to explore Europa is also Central to habitability because that radiation environment
creates half the chemistry that might be needed for life but it also allowed us to detect europa's
ocean in the first place um Jupiter has a large time varing magnetic field and as Europa goes
around it we noticed it produced a field that was similar to but but offset from the Jovian
field uh that we call an induced field it's the same way a wireless charger on your phone works
where you send a Time varying electrical current through a loop of wire and it induces a magnetic
field you have a loop of wire on your phone and that magnetic field then induces a current well as
Europa goes around Jupiter we notice this induced magnetic field and similarly the only way that
that could be happening is if there was a large Global conducting layer uh the most consist layer
that we understand is a large saltwater ocean and so by sensing the magnetic field around Jupiter
and around Europa we can tease out properties of that ocean like how salty it is and how deep
it is so all of these processes come together to really help us close this test of the Europa
habitability hypothesis involving oxidants produced at the surface and a reducing water Rock
interaction at the seafloor being brought together by active geology in this thick icy shell to
potentially support a habitable ocean having seen it go from really paper studies of how to
answer these science questions to Hardware that's built and and sitting at the cape with a window
opening in October is indescribably exciting these are missions that are National in scale or
really civilizational in scale that fundamentally change our understanding of the solar system and
our own world it's exciting to think about what might come next and what might ultimately result
in testing a life hypothesis but I really can't overemphasize how exciting it is to be here in
this moment where we're testing the habitability hypothesis because it really is a a new step
forward in how we think about the exploration of astrobiology and so it's this really critical
moment where I feel like we're we're just coming together to ask the question questions of what is
it we think life requires and and how to explore that and how these processes interact and they're
really hard questions and yes it's exciting to think about someday how we would do life detection
directly but the steper at and thinking about how to close the problem and all of the variety of
people involved I I think is just as compelling