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welcome and thank you for standing by at
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Wayne brown you may begin sir
well thank you operator and good
afternoon to everyone again my name is
Duane Brown with NASA's Office of
Communications here at NASA headquarters
and gotta tell you we've got a good one
today a couple of days from now
Wednesday October 28th NASA's Cassini
spacecraft will sample an
extraterrestrial ocean the spacecraft
when it flies directed through the plume
of icy spray coming from Saturn's moon
Enceladus will have brief presentations
from our Cassini team they will be using
graphics and just a reminder those
graphics can be obtained at WWDC gov
slash Cassini slash Telecom that's WWN a
see gov / Cassini CAS sini / telecon te
le Co n this teleconference will be
replayed in its entirety for several
days the replay number is 803 nine one
nine eight five one again that's 800
three nine one nine eight five one and
of course social media is abuzz about
what's going to take place in a couple
of days send in those questions social
media they're already coming in and we
will be hearing some of those questions
at hashtag ask NASA follow the
conversation Twitter Facebook YouTube a
lot of excitement so extraterrestrial
ocean Wednesday October 28th you're here
from starting with Kurt neighbor Cassini
program scientists at NASA headquarters
in Washington
Errol Mays Cassini project manager at
NASA's Jet Propulsion Laboratory in
Pasadena California and Linda spill ker
the Cassini project scientists also at
JPL so let's get started and I'll toss
it to Kurt
Thank You Dwayne the Cassini mission is
incredible
the
has provided nonstop discoveries for 11
years now and Kelly Cassini has
demonstrated two things to us over that
time span first that the universe will continue to surprise an amazing and
second that we as the people have the
ingenuity and the passion to reveal and
to revel in those surprises Enceladus a
tiny cold icy moon orbiting Saturn very
distant from the warm Sun has been the
source of some of the most amazing and
unexpected of our discoveries in the
Saturn system early in the mission we
discovered Jets of water erupting from
the South Pole of this world forming a
huge plume stretching thousands of
kilometers into space more recently we
learned that just like Jupiter is a
larger moon Europa
there is a global liquid water ocean
under Enceladus as icy crust and we also
discovered evidence that there is
hydrothermal activity reactions between
the the hot rock and the liquid water
occurring inside and Celer this at the
bottom of that ocean so in some of this
is not just an ocean world it's a world
that might provide a habitable
environment for life as we know it
and while the Cassini spacecraft does
not have the instruments needed to
detect life it does have the instruments
that can tell us about the
characteristics of that ocean and as
though it is those characteristics that
control habitability that control
whether or not life on Enceladus is even
a remote possibility as you can see in
the first graphic which shows a cutaway
of Enceladus that the ocean that we're
talking about covers a huge area and
that's why in Stella this is a world
that is becoming a key destination in
NASA's search for life and on Wednesday
we will plunge deeper into that
magnificent plume coming from the South
Pole then we ever have before and we
will collect the best sample ever from
an ocean beyond Earth and this is an
example of where our passion and
ingenuity can take us and this is an
example of what NASA is all about so now
I'd like to introduce Earle Mays from
the Jet Propulsion Laboratory of
Pasadena
Earle is the project man
for the Cassini mission great thanks
Kurt um we have a rather prosaic term
for this flyby it's e 21 it's our 21st and celtuce flyby it's not our last but
arguably this one is going to be our
most most dramatic we're going to be
screaming over the South Pole at around
19,000 miles per hour just 30 kilometres
per sorry 30 miles above the surface and
we're going to go right through the
plume we've been in the realm of the icy
satellites now for a few months sample
some of the intelligences neighbors
Dione Andrea have been on our our list
of targets but now it's Enceladus last a
couple weeks ago we had a phenomenal
flyby of the North Pole as Enceladus
first time we have seen this area of the
satellite in sunlight and now it's the
South Pole with the plume I'm speaking
to the graphic we have as I said been in
there in the ring plane essentially I
see satellites and we're now on approach
to Enceladus about two hours out we've
been imaging all the way in on approach
imaging as usual as prime coming in but
about two hours out or this animation is
now we will be rewriting the spacecraft
so the apertures of both are dest on
Eliezer and spectrometer going right
through the plumes and you're watching
the animation it is going to be over in
an instant we are going like I said
19,000 miles per hour through the plumes
we'll just take a few tens of seconds on
the egress we will have a phenomenal
view of the backlit plumes against the
backdrop of Saturn and the Rings with
the data safely onboard we will then
begin to reorient the spacecraft for
some final imaging all this is going to
happen about 10:00 a.m. on Wednesday
morning local time specific day light
stops daylight savings time we will hear
our first call back from the spacecraft
at about 4:15 that afternoon that will
be just a health and safety call we're
going to reorient the spacecraft for its
next encounter and we will then be able
to play back the day over the next
couple of days although we will be going
way too fast
to precisely target the surface at
closest approach we're not going to let
leave imaging out what we'll be able to
do is essentially drag
the open apertures of the instrument hi
the narrow angle and widening on cameras
across the surface shuttering like Matt
and if you can look at the ground track
of the maze to image now the red line is
the ground track of the cameras those
white circles are the images of the
active areas Jets and plumes and or
curtains as you may choose we hope if
you see one of those actually crosses
what we've been calling areas 68 which
is a very active region at the lower
left and although these images will be
quite dramatically smeared because of
our velocity the imaging technology
should be able to remove the smear and
we should be able to have some pretty
spectacular images for you one last
thing to point out about this image is
that as I pointed out earlier the North
Pole is in daylight for the first time
ever unfortunately that means the South
Pole is not and so all of these images
will be taken with the ambient lighting
from Saturn in other words Saturn shine
it'll be a lot like the moonlight we see
in the in a full moon but this time it's
going to be Saturn providing
illumination for the images and with
that I will turn this over to Linda
Stoker the project scientist for Cassini
thanks Earl
I'm going to discuss our plan science
and anticipated results from this
incredible fly by Cassini will undertake
three main science activities during
this flyby and each activity is designed
to provide powerful new insights into
the habitability of Enceladus ocean
they're going to do that by further
studying both the gas and the particles
coming from the South Pole stoker one
shows the four bluish tiger stripes what
you're seeing is a tiny moon only 300
miles across though as for blueish
features are at the South Pole
those tiger stripes but this is the
source of the gas and the particles
coming from the South Pole of Enceladus
the first objective is to confirm the
presence of molecular hydrogen in the
plume gas and this will provide an
independent line of evidence for the
hydrothermal activity that Kurt
discussed that's taking place on the sea
floor of Enceladus the amount of
hydrogen emission will reveal for us how much hydrothermal activity is
actually occurring on that sea floor
with implications for the amount of
energy that's available energy a key
ingredient for habitability on Enceladus
Cassini's second activity is to better
understand the chemistry of the material
in the plume we know we've seen organics
we've seen methane carbon dioxide number
of key ingredients and this in this case
with our much deeper dive through the
plume we'll have a chance to sample
potentially larger particles and a
greater density of both the gas and the
particles and we might find new organics
that we haven't seen previously or
adjust at the limits of our detection in
stoker 2 you can see a video of the
plumes continuous emission keep in mind
the South Pole is in darkness so
there'll be actually a shadow line
across the plume we'll get in particular
images as we fly outbound in what we
call forward scattered light to look at
this plume coming out of Enceladus and
the third and final activity is to term
to determine the nature of these plumes
sources what we wonder are the plumes
created by tight column like Jets or
curtain like eruptions that run along
the length of each Tiger fiber strike
fracture if you look at spoker 3 you can
see that there's evidence perhaps for
jets but also these curtains of
admission and this is an ongoing source
of debate within the scientific
community about just what this emission
looks like it also has major
implications for how long Enceladus
might have been active and keep in mind
again at the South Pole is dark but
we'll see the plume as they go up above
the surface of Enceladus
we'll get images both inbound and
outbound on this flyby and we'll have a
first chance to look at the gas and
particle data within about a week of the
flyby a first quick look and then over
the coming weeks we'll do a more
detailed analysis to really help us
understand what's going on in that
tantalizing ocean on Enceladus and this
flyby may help us unlock more details
about the habit
ability of this very tiny ocean world and with that back to you Kurt for some
concluding remarks Thank You Linda as I
mentioned this flyby can't detect
license we don't have the necessary
instruments for that but it will provide
powerful insights as to how habitable
the ocean inside and some of this might
be insights which Linda just described
so I hope we give you a good idea of
what this flyby means and how very
exciting it is for the the Cassini team
and I hope we've also given you an idea
of how exciting it is not just for us
but for everyone every every single one
of us on the planet
this is a very big step in a new era of
exploring ocean worlds in our solar
system these are worlds with huge bodies
of liquid what water underneath their
services bodies with great potential to
provide oases for life throughout our
solar system it's a journey and
understanding about what makes the world
habitable and where we might find life
and where we might one day live
ourselves and everyone is invited to
join us on this journey
thanks Kurt and thanks to a fantastic
conceding team so ladies and gentlemen
nice in to the point and we've got
plenty time for questions so we're now
going to transition in QA I'm going to
turn it over to the operator to help
facilitate that will take several
questions from the media and then we're
going to go to social media with getting
lots of lots of conversations so we have
them get a chance to answer some
questions and then we'll go back to
media so with that operator over to you
thank you this time we're ready to begin
the question and answer session if you
would like to ask a question please
press star 1 you will be prompted to
record your name to withdraw your
question you may press star 2 again star
1 to ask a question in one moment please
for our first question
our first question comes from Greg
Redfern with WTOP radio space reporter
Jimmy after question thank you for
taking my call this is for Earl or Linda
and what an exciting mission but I have
essentially two related questions have
you already identified the plume that you want to fly through or
is there a constant stream of food that
cusine will will fly by and number two
exactly or how much light do you expect
to fall on the South Pole of the moon
from Saturn thank you so much and a
great mission congratulations
okay the plume of Enceladus is
continuously erupting we've seen it
throughout the mission and so we'll be
flying through that plume perhaps even
helping resolve the question of the Jets
versus the curtains as you could see
from that red line on maize - that we're
going to be going across what appear to
be discrete sources and going close
enough to perhaps determine if they are
discrete sources or part of a larger
curtain as far as the intensity of light
falling on the moon from Saturn it's
going to be much much less than the
light coming from a full moon
Saturn is 10 times further away from the
Sun than the earth is so you've got like
a factor of 100 decrease in that light
so it'll be dim light but we have very
very capable cameras and we've done this
before looking at the dark side of moons
and Saturn shines so we'll be able to
get something out of it our exposures
will be long so some of those images
very close to the South Pole may be
smeared but we think with some
processing we can take some of that
smear away and I might add that
Enceladus until this is very bright
which also helps us thank you are you
ready for the next question
and are you ready for the next question
yes thank you this question just comes
from bill Harwood with CBS News go ahead
with your question thanks Ann I have two
very quick ones
one for all and one for Linda if I could
Earl I think you or someone once said
that this kind of like swimming through
smoke I just was looking for some
general comments on safety spacecraft
whether you would have done something
like this earlier in the mission then
now we're toward the end of it does that
make the risk a little more acceptable
and so look now you may have said to
decide to step back for 30 seconds and I
apologize but are we thinking tidal heating alone is responsible for keeping
this ocean liquid or is there a
component of radioactivity that's doing
this or is it mostly title thanks yeah
that would have been me I would have
said something like that or through
steam or vapor we have flown through the
plumes before at a higher altitude not
quite so done and so yeah this is a
little bit riskier but not that much we
really feel like we're taking a very
prudent approach at this point in the
mission we still have a couple years
left a lot of exciting stuff still to do
so we're not going to risk everything on
this one flyby that helped yeah I could
add that the part of the particles
themselves we think are on the order of
about 30 microns or so so very very tiny
particles and very diffuse also and
spread out as far as the the source of
the energy for Enceladus we think it's
primarily tidal heating a lot of the
radiogenic heating has since gone away
so we think it's primarily tidal heating
although there still is a puzzle because
tidal heating as we best understand it
doesn't quite provide enough energy to
maintain and tell this is ocean liquid
perhaps from the time it formed so we're
working on that one right thank you
our next question comes from Irene Klotz
with Discovery News you me after
question thanks very much um I have two
questions the first one for Earl what
was the previous closest encounter over
the Enceladus feather in pole and for
Linda
I understand that Cassini is not a life
detecting mission at all but is there
any chance at all that the analysis of
the gases and the dust could turn up
anything that would kind of shed light
on bio signatures at all or is that for
another mission Thanks
yeah next closest to the plumes was 50
clump 50 miles sorry and not through the
densest part of the plume says we're
doing now yes over the South Pole it was
about 50 miles so where we are going
considerably closer but I think our
closest flyby of Enceladus was 15 miles
right but that was not through the poles
so they're not concerns we know exactly
where we are where Enceladus is the plume density that we're working on now
as far as the the life detection with
Cassini we can really only detect
complex organics we don't have the range
of mass detection to find anything that
would DNA or or larger molecules that
would indicate life but we can really do
a lot with Cassini to address how
habitable is that ocean on Enceladus so
it really remains for another mission
perhaps a series of flybys with the
right instrumentation maybe an Enceladus
orbiter or perhaps a sample return
mission to bring back samples of that
material then use the sophisticated
instruments on earth to take a look at
that material thank you and this
question comes from Jason Ryan with
space fighter insider.com go ahead with
your question I'm sorry bill already
asked my question thank you thank you
our next question then comes from Peter
spots with the Christian Science Monitor
we'll have a question well thank you
very much for doing this and I think
this is for Linda's bulgar I wonder if
you could return to the Curtin versus
sort of collimated plume idea and kind
of give us a sense for what difference
that makes to what ideas about these
conduits or
about the sources or whatever in the
case of the jet should have discrete
individual you can think of like little
nozzles spraying out this material into
space whereas in the curtain analogy it
would be more like a continuous crack
that's open similar to a lava curtain
that you might see in Hawaii and so it
just helps us better understand how do
you interact through the ice shell up on
to the surface and so that's what we're
trying to figure out the difference
between those two
thank you thank you next question comes
from Alexandre witzy with nature
magazine let me ask a question yes
thanks for taking my question
I think my question is for Earl I just
wanted to add specifically about the
timing of when we're expecting perhaps
the most dramatic images from the
passage what I would expect would be
sometime late in the evening of Thursday
we have a track right after the flyby but
because of the way the orbital
dynamics are we've got to do a cleanup
maneuver right then so we won't get much
playback on the first day the second day
we've got one of the largest antennas
down in Canberra a 70 meter playing back
all day but it starts about 4:15 in the
afternoon so the imaging and all of the
the close closest encounter flyby data
will come back then take some time to
process and clean them up I wouldn't
hold out hope for anything before
Thursday evening and most likely Friday
or into the weekend because of the
complexities of removing this mirror so
operator this is a Dwane Brown we are
going to come back to the media calls
we're going to go now to social media
and ladies and gentlemen we have Jason
Townsend our social media manager we're
going to take several questions from
social media and then we'll come back
with your media calls Jason sure our
first question comes from Twitter user
sandwich will the Queen's alter the
course of the Cassini ship know which
we're going so fast and its really so so
diffused that it will have a little
they'll have no effect that we can
measure on the trajectory the spacecraft
great next question comes from Twitter
user Melanie who asks what would
resolving the Jets versus curtains
question tell us about the moon
resolving this question would tell us
about how the ocean is interacting with
the surface whether you have individual
little conduits coming up or basically
sort of an open crack that goes all the
way to the bottom of the ocean and this
would just help us better understand
this interaction and maybe tell us more
about the thermal energy also coming out
of these fractures our next question
comes from Twitter user David who asked
what hypotheses are there about why the
geysers only occur on the South Pole
that's a very good question and one we
pondered about our flyby just two weeks
ago we looked carefully at the North
Pole for possible evidence of activity
that may have occurred there in the past
we think though for some reason that
there's a just a region there at the
South Pole maybe it didn't start out at
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