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- [Louise] Thank you,
Tiffany, can you hear me okay?

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[Tiffany] Yes, I can hear
you great. Thank you.

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- [Louise] Okay, good.

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So great first time to
go, no technical problems

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that said that last.

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And I apologize now,

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I have to get off to
another meeting at four.

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So, unfortunately, if
anyone has any questions,

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please just email them to me.

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So if we could go to the first real slide.

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So, thank you very much
for the invitation today.

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So I'm excited to talk about Trident.

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Trident is a mission that would fly

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through the Neptune system

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to investigate Neptune
largest moon Triton.

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This is certainly one
of the strangest moons

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in the solar system

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it's also the seventh largest

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and it's largely unexplored today.

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We have three main objectives.

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The first one is related to the fact

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that Triton provides a great opportunity

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to explore one of the ways in
which worlds become habitable

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through the presence of liquid water.

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Triton appears to have started
life in the Kuiper Belt,

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but was captured around
Neptune early in its history.

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We know this because Triton shared

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compositional similarities with Pluto,

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but also because it's in
a very highly inclined

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retrograde orbit

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that doesn't usually happen

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from forming in situ around the primary.

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And this inclined orbit
enables a tidal interaction

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that leads to something called
obliquity tidal heating.

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Cathy Mann talked a lot
about tidal heating earlier,

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when she presented Ivo.

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And this is a slightly
different kind of tidal heating,

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which the thermal energy is
deposited into the liquid

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rather than the icy shell of an icy body.

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And because of the inclined orbit,

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we think that this ocean
is present within Triton

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to this day.

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And so we are hoping to determine

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whether there's an ocean there or not.

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And of course, if an ocean is there,

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it's an example of a way

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in which one of the elements
of habitability can be created

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to an unusual evolutionary pathway.

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And so that's one of the reasons

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why Triton is such an interesting body

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to people who are
interested in ocean worlds

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and habitability as a whole.

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So one of our main
objectives is there an ocean?

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But we also want to look at
what processes are present

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on active icy worlds.

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So the only spacecraft

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to have encountered the Neptune system

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was Voyager 2 in 1989.

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And you can see some of
the surface of Triton here

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on the right is some very unusual,

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unique terrain called cantaloupe terrain.

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If you were, I don't know a cosmic giant

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and you reached out and touch Triton,

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it would feel like a
cantaloupe in some areas.

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It's very unusual surface.

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But what's also interesting

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is there are very few impact craters

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and the surface is
actually extremely young,

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possibly as young as 10 million years,

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which would make it

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the second youngest
body in the solar system

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surfaced in the solar system next to Io.

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So we want to understand how
these kinds of terrains form.

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Voyager 2 also found plumes,
active plumes on Triton,

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that saw at least two
that went eight kilometers

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up before heading down
wind and then persisting

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for about 150 kilometers.

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And also over a hundred
dark streaks and fans

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on the surface that are probably

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Relic to fossil plume deposits.

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So we want to go back
and revisit these plumes.

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Originally, they were
thought to be the result

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of sublimation processes
in the nitrogen ice

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near Triton South pole.

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But we're now starting to
reevaluate those models

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because we've seen plumes at
Enceladus and also at Europa.

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So, what are they, and are
they actually cryovolcanic?

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Are they coming from
an interior subsurface,

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liquid water, possibly an ocean?

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We also want to look at
why Triton's ionosphere

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is so intense. It's an order
of magnitude or more higher

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and intensity than any other
ionosphere in the solar system.

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And ionosphere is usually
driven by solar energy,

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but we're out at 38 years,

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so we're a long way from anything else.

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And so that's been an ongoing mystery

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since Voyager that we
were actually going to fly

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through the ionosphere.

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So we hope to determine
why is it so intense?

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And then finally, Voyage 2 only fill 40%

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of the surface of Triton?

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In fact, the area to the top right here

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is pretty much all Voyager 2 Solar.

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So about 60% of this moon
has never been viewed

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by a spacecraft and a
space-based telescopes,

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haven't done a particularly good job

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of resolving the surface of Triton.

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So this is pure exploration as well.

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And if we can go to
the next slide, please.

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So how are we going to do this?

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And how are we going to get to 30

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a year on a discovery budget?

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$500 million cost cap,

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you know, obviously sounds like a lot,

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but in planetary terms,
it's one of the smaller

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classes of measures.

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And the reason we can
go far out to 30 a year,

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which is what? Five
times further than anyone

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who's gone prior to now,

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is because we have a
very small spacecraft.

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We can use a simple ballistic trajectory,

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which means we don't have
to carry a lot of fuel,

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and we're powered not
by huge solar panels.

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I don't think they would
even work that far out

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into the solar system.

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But by two radio isotope
thermal generators,

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which with those and
batteries we can take data

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all the way out.

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So we have a 10 day encounter at Neptune

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and the orbital mechanics of Triton

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are such that Triton is
going to rotate beneath us

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or alongside us as we fly by.

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So we get nearly global
coverage of Triton.

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So it's a really serendipitous opportunity

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to go at this time, but
we are time limited.

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And I know I'm running out of time.

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So if I could just go to the third slide.

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So I'm not gonna go through all of this

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but obviously this is
an exoplanet meeting.

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We are not currently
in our baseline looking

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in that tune right there.

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One of the things about discovery is that

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the cost cap is such that
we're very focused on Triton.

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It's an active well mission,

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but of course, we're
flying through the system.

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We've got some very
sophisticated instruments.

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And so we are also
going to look at Neptune

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and right now we're looking at

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what possible opportunities there could be

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to do science at Neptune.

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And that would allow us to understand

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Ice Giants around other
stars in a new context.

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So getting outside as a
sort of near observations,

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and we will also make observations

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that will allow us to
compare to observations

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of Neptune, since
Voyager from ground based

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and space based assets.

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And so I think these slides
are gonna be available to you,

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but just on the bottom here
is a table just showing...

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just some of the things
that we're thinking about

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at the moment,

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but if you've got any ideas of things

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that would be particularly
useful for exoplanet science

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that we can do at Neptune with

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a fairly nice narrow angle camera,

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we've got a nice infrared
plasma spectrometer,

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and magnetometer.

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So, we will be studying
the Neptune environment

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as we fly through. But please let me know.

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Because we're considering those now.

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And with that, I think
I probably either hit

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or have gone beyond my seven minutes.

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- [Tiffany] No, that's perfectly fine.

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Yeah. We've been running a bit behind far.

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So I apologize with the time crunch.

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But thank you.

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Yeah, we'll send out an
email to the presenters,

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but there's an online website slider

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where people are posting their questions.

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And so you can take a look at a later time

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and respond in kind as things pop up.

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So thank you again, Louise, take care.

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- [Louise] Thank you very much, Tiffany.

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- [Tiffany] All right.