imagine yourself about six months ago
around midnight
September 15th up on the hills above
Thessalonica say at the Acropolis or the
castle looking southeast near the waning
gibbous moon in the stars of ficus you’d
see Saturn slowly rising above the
horizon a very serene very unremarkable
scene seen many times before but it’s
Saturn something very very different
what’s going on the Cassini spacecraft
an emissary from Earth was screaming
over Saturn’s North Pole it had recently
turned at Santana back to earth to
transmit its data that had gathered over
the last couple of days but this time
was very very different Cassini was on a
collision course with the planet it was
going to skim into the Saturn’s
atmosphere and its velocity its
termination was inevitable a one-way
trip for the spacecraft let me take you
just heard the signal from the
spacecraft just go on within the next 45
seconds Cassini’s mission ended
September 15th after 13 years of Saturn
back on earth we were both triumphant
and somewhat somber as we say goodbye to
our faithful Explorer and I must say in
some sense old friend
Cassini’s end of mission because exceed
new spacecraft terminated ended in a
fireball high above the clouds of Saturn
it was the final chapter of Cassini’s
investigations 22 orbits between the
Rings and the planet ending in a
fireball above Saturn the Cassini flight
team was able to use every last
capability of the spacecraft and every
last second of the mission to transmit
data seven years earlier they’d taken
advantage of a breakthrough in
astrodynamics an astrodynamics
breakthrough the allowed three things to
happen first of all we could use all our
fuel every last kilogram exploring the
system because if we got to the right
place at the right time everything else
would be taken care of for us this
mission design allowed the spacecraft a
complete and an ultimate disposition
within within Saturn and I’ll get to a
little bit later about why that is
important and finally this mission
design would allow us to go into an
unexplored region of Saturn as I said we
spent 13 years there we’ve been all over
the place but one place only we hadn’t
been what right between the Rings and
Saturn themselves itself 22 orbits into
that gap and exploring places we had
never seen before
after the voyagers went by Saturn in the
early eighties it became very very clear
that the world needed to go back
the Cassini actually cassini-huygens
mission was an international venture
right from its very conception it was
proposed by a kitty a small team of
international scientists it was accepted
by an International Congress of
planetary scientists and then
implemented by three space agencies 19
member nations hundreds of international
contractors and thousands of
engineers it took 15 years for that
consortium to get from concept to launch
and another seven years to get to Saturn
and all Cassini spent more time in
concept and it did in flight the total
system consisted of 18 instruments 12 on
the orbiter 6 on the probe and it was
chartered with the Saturn system first
of all the planet itself a giant ball of
hydrogen and helium swirling with storms
and whose internal structure was fairly
unknown the beautiful beautiful rings
who have first sighted by Galileo in
1610 and have been a mystery pretty much
ever since
Voyager told us a lot about the Rings
but raised as many questions as answers
and as a matter of fact we’re still
arguing about how old they are the
enigmatic moon Titan Titan is a moon of
Saturn but if it weren’t for it had not
succumbed to get Saturn’s gravitational
pull it would be a planet larger than
mercury larger Thunder a moon it is
covered with a thick organic haze of
nitrogen and hydrocarbons and then
finally the retinue of not finally but
the retinue of Saturn satellites Saturn
has been busily collecting material from
all over the solar system some of it
it’s generated itself some it’s captured
from the Kuiper belt
Jupiter helps a lot it brings things in
and Saturn picks them up 62 of the most
eclectic combination of moons you’re
ever going to find and when you got to
an awful lot of them and then finally
the intense magnetic and electric fields
and dust that surround the planet let me
just walk you through a few of the
highlights of our discoveries in those
13 years before I get back to the grand
finale
first of all Saturn covered with lots of
small storms but Cassini was lucky and
got a one-in-a-lifetime
of one who’s at 30 years I should say
just a wonderful one in Cassini lifetime
opportunity the so-called 30 year storm
a monster storm that began in Saturn’s
upper latitudes raged all the way down
into the interior of the planet pulled
material out to the surface and was
churning we were actually able to
some of the interior of the planet
through this storm it persisted for
almost two years and as it slowly
wrapped its way around the planet the
head and the tail met and within a few
months the storm collapsed you can still
see it’s heat signature today but Saturn
looks exactly like it did in that
picture on on your left the North Pole
of Saturn a jet stream that is persisted
for almost 40 years and in the middle of
it a hurricane the size of France the
winds around the edge of that hurricane
are going about 540 kilometers per
second and again this is persisted it is
almost all by the way that’s not the
real colour we’ve done a little bit of
enhancement there just to keep social of
the contrasts the Rings are lettered a b
c d e f g h and they’re named in order
of their discovery but what we found in
voyager saw this first these rings are
not ABCD there’s a 1 2 3 4 5 6 7 8 9 10
and they keep on going the rings are
nothing but many many many many many
rings and they just go and go and go
it’s the closer you look the more
associated in the rings and I’ll get
back to that a minute but here’s going
to show you one of our favorite my
favorite pictures actually our favorites
every 15 years the Sun comes right edge
on to Saturn and it filled an earth the
Rings appear to disappear because they
are not illuminated but from Saturday’s
point of view you can look down over the
top now you’ve probably all seen
photographs of the pyramids at noon you
can barely see them but at sunset they
cast these long shadows across the
desert floor just what you’re looking at
here those shadows are the shadows of
big clumps in the Rings cast over the
much smaller material most of the Rings
are only a few maybe 100 meters thick
they’ve been squashed down by Saturn but
out of the edges of the B ring here you
can see things that are the size of a
kilometre massive chunks of ice and rock
so we’re able just by being persistent
to determine some of the ring structure
with the photography itself
this is one of my favorites as well just
because it’s the F ring is this outer
thin band and it’s a very tortured ring
because it’s got two little shepherd
satellites that are constantly messing
with it and you can see one of them down
there in the lower right and you can see
that little knot it’s pulled into it
there’s a constant sense of turmoil in
the F ring because as soon as you get
stable either pan or Pandora or Capri
theate Prometheus or Pandora come by and
and churn it up again and then this is
kind of fun a lot of times when we’re
taking pictures of the Rings you know
you’ll see a moon or satellite some some
a little photo bomb but this one was
particularly fun because if you look
closely at that that’s not a moon that’s
not a star that is the earth taken from
a billion miles or a billion kilometres
away and if you look closely at the
inset you can see Earth’s moon as well
so one of our favorite family portraits
everybody’s there and then Titan Titan
from voyagers point of view and from the
Earth’s point of view was just a big
fuzzy ball covered with essentially you
know the equivalent of smog I’m from Los
Angeles and I can tell you all about
that we couldn’t see through it so one
of Cassini’s missions was to penetrate
through that fog with the many
instruments that carried and understand
what was going on in the surface the
first thing we did was we landed the
European Space Agency’s probe onto the
surface of Titan and a period of two and
a half hours when we went from that to
this that is a picture from a surface of
Titan by the european probe as it slowly
paired a parachuted down to the
atmosphere and imaged the surface that’s
a dry lakebed believe it or not those
rocks are not well they’re rocks but
they’re water ice at a hundred and
seventy 180 degrees below zero so
degrade water is as hard as granite and
has taken the place of the silicates
that we expect here on earth but the
liquid is now methane and ethane simple
hydrocarbons that freeze at a much lower
temperatures and this was once a methane
lake
has since dried up oh and just for
contrast let me show you that’s a
picture of the Apollo astronauts
footprint just to give you some idea of
the size size of those rocks by the time
we were done exploring Titan thirteen
years later we discovered tight to is an
earth-like world it has rivers it has
lakes and it has seas now they’re not
water they’re ethane and methane
hydrocarbons more hydrocarbons on Titan
than there are over the entire earth if
we get a pipe up there we’d be in great
shape
dooms much like the students in
equatorial and the equatorial regions of
the United of the earth mountains clouds
and rain an entire meteorological cycle
those rivers are filled with rain they
fill the lakes it evaporates it goes on
and on and then finally as I showed you
dry it will dry riverbeds that Huygens
showed us and then here’s the biggest
surprise from Saturn all Enceladus the
Enceladus of Voyager was a white
snowball but we didn’t quite understand
the Enceladus from Cassini was
marvelously resolved by the images but
what was even more important this little
300 kilometer sorry 500 kilometer
snowball actually had geysers a total
surprise to everybody
it just seemed impossible that something
that small could be active well by the
time we were done Ravech during the
mission to explore Enceladus we had
discovered that Enceladus was indeed had
an active Jets and a subsurface ocean
over the entire moon
five hundred kilometers fairly big
enough to pull itself together and it
had notion the ocean was global the
water was salty the long-lived and there
are hydrothermal vents that water in the
ocean is hot and there’s actually enough
heat to almost boil it coming from
Enceladus it’s irrefutable the ocean is
the plenty of height of heat energy and
even more compelling molecular hydrogen
an essential ingredient for life and
you’ve got organics in the plume coming
from the ocean so you’ve got heat you’ve
got salty water you’ve got hydrogen you
have
all the components for astrobiology now
no one’s saying there’s life at
Enceladus but this has turned us around
about what Enceladus could possibly be
and where life could be and there’s a
graphic illustration of what out of what
it might look like on the surface of
Enceladus so that leaves us with the job
of protecting Saturn’s ocean worlds
which is why we decided to destroy a
discovery machine but not before we had
done the grand finale 22 orbits through
this incredible gap so I need to show
you quickly what we meant by that let me
just go you to a graphic to a poet or an
artist
Saturn is beautiful and the Rings are
graceful but to an engineer both of them
are hazards if we get too close to the
atmosphere we would tumble out of
control if we got too close to the Rings
you can see at 120 kilometers per second
we had a little chance of survival so we
had this very perilous course to try to
stay through the gap so to speak and it
was very important that we manage to
keep directory carefully so let me show
you something really kind of fun here
what we decided to do was keep the
antenna the main dish of the spacecraft
pointing into the dust for the first
travel through to see what happens so
listen to this this is what we expected
to hear this is coming through the F
rings write that chart is actually we’re
using the main antenna and then as the
particles hit it we’re turning those
into sound so you could actually hear
the increase as the spacecraft travels
through the passageway so this is what
we expected and if we got something like
this we’d be fine we’ve done it plenty
of times before no big deal so we did
this sort of thing with the first
passage through and we got this you can
see from the picture there is just
nothing going on we had to exaggerate it
even to get any sound at all so what
turned out to be something of a great
fear for the mission turned out instead
to be a great surprise
we had nothing to worry about so the
spacecraft guys were all you know
scientists got a puzzle they’re happy
where’s the desk oh we’re happy because
we’ve got no problems with going through
the gap and the atmosphere messed with
us a little bit but we we figured that
out as well so here just a few of the
final photos in those final 22 orbits
the ring satellites pan as you can see
get carving a gap in the Rings Atlas
also has carved a gap in rings and both
these have little mini skirts around
them of ring material they’ve actually
about as big as they can get any bigger
and Saturn will rip them apart and then
finally this beautiful little moon
Deafness that’s running around in the
Keeler gap and you can see the waves of
gravitational dispersions that is put on
the weight rings and let me give you a
close-up of this so fascinating these
little ripples dissipate after a little
while but they just followed after sit
around as it shuttles around through the
Rings and this is a family portrait and
I a fight a flight team is just like an
army it runs on its stomach so I
couldn’t stop them from doing this and
they do look like pierogies Hamas say
the Rings incredible resolution of the
Rings especially the straw colored
material to the left and then another
picture of the Rings showing the entire
internal history of the Saturn every
time Saturn burps or gurgles its ripples
the Rings and its entire history of
Saturn is captured in time from the
upper right lower right to the upper
left in this illustration finally the
last day Saturninus rings Titan
Enceladus setting over Saturn ice
structures within the Rings themselves
and we had discovered earlier and moon
forming on the outer ring of Saturn the
outer a ring the investigator named it
Peggy
after his mother-in-law and so he took
one last picture of Peggy Saturn
approach this is an image again an art
artistic running of the Saturn of
cassini on its final approach to saturn
it had one last job to do because if we
were really going to keep all our
promises Cassini was now going to become
an atmospheric probe we were going to
sample the atmosphere something that had
never been built to do and then return
the day to earth so we first turned the
antenna towards the earth we turned on
the instruments that could be useful at
that time we configured the spacecraft
to play everything back and then into
the atmosphere we meant the whole
strategy from then on was just hang on
stay pointed the earth as long as we
possibly could to keep the data plane
thrusters were fighting against loss of
control they were not as you can see
from this picture this is not built for
speed in the atmosphere they were
fighting and fighting and fighting
against the incoming encroaching
atmosphere and for the Larry very last
second Cassini was returning data
finally as you can see the spacecraft
vibrations became more and more
oppressed by the atmosphere and it
wasn’t long before the thrusters gave up
we lost contact with a spacecraft
shortly thereafter we lost contact
destroyed became a part of the very
planet it was sent to explore safely out
of harm’s way
it entered Saturn and was vaporized this
is again an artist’s rendering of what
we think was probably Cassini’s last
view as it went into Saturn 15 years I’m
sorry 13 years of exploration the
spacecraft finally ended but not before
it had opened our eyes and revealed an
incredible world a world that has
rewritten and rewritten again the text
on planetary exploration and planet
formation it has made us rethink what we
have to do what we what we think about
astrobiology and it just begs us to come
back again it’s a tribute to the
international effort and the might of
the the world’s people in getting this
thing off the ground and again revealing
the universe to us all if he’s thought
[Applause] [Music]
around midnight
September 15th up on the hills above
Thessalonica say at the Acropolis or the
castle looking southeast near the waning
gibbous moon in the stars of ficus you’d
see Saturn slowly rising above the
horizon a very serene very unremarkable
scene seen many times before but it’s
Saturn something very very different
what’s going on the Cassini spacecraft
an emissary from Earth was screaming
over Saturn’s North Pole it had recently
turned at Santana back to earth to
transmit its data that had gathered over
the last couple of days but this time
was very very different Cassini was on a
collision course with the planet it was
going to skim into the Saturn’s
atmosphere and its velocity its
termination was inevitable a one-way
trip for the spacecraft let me take you
just heard the signal from the
spacecraft just go on within the next 45
seconds Cassini’s mission ended
September 15th after 13 years of Saturn
back on earth we were both triumphant
and somewhat somber as we say goodbye to
our faithful Explorer and I must say in
some sense old friend
Cassini’s end of mission because exceed
new spacecraft terminated ended in a
fireball high above the clouds of Saturn
it was the final chapter of Cassini’s
investigations 22 orbits between the
Rings and the planet ending in a
fireball above Saturn the Cassini flight
team was able to use every last
capability of the spacecraft and every
last second of the mission to transmit
data seven years earlier they’d taken
advantage of a breakthrough in
astrodynamics an astrodynamics
breakthrough the allowed three things to
happen first of all we could use all our
fuel every last kilogram exploring the
system because if we got to the right
place at the right time everything else
would be taken care of for us this
mission design allowed the spacecraft a
complete and an ultimate disposition
within within Saturn and I’ll get to a
little bit later about why that is
important and finally this mission
design would allow us to go into an
unexplored region of Saturn as I said we
spent 13 years there we’ve been all over
the place but one place only we hadn’t
been what right between the Rings and
Saturn themselves itself 22 orbits into
that gap and exploring places we had
never seen before
after the voyagers went by Saturn in the
early eighties it became very very clear
that the world needed to go back
the Cassini actually cassini-huygens
mission was an international venture
right from its very conception it was
proposed by a kitty a small team of
international scientists it was accepted
by an International Congress of
planetary scientists and then
implemented by three space agencies 19
member nations hundreds of international
contractors and thousands of
engineers it took 15 years for that
consortium to get from concept to launch
and another seven years to get to Saturn
and all Cassini spent more time in
concept and it did in flight the total
system consisted of 18 instruments 12 on
the orbiter 6 on the probe and it was
chartered with the Saturn system first
of all the planet itself a giant ball of
hydrogen and helium swirling with storms
and whose internal structure was fairly
unknown the beautiful beautiful rings
who have first sighted by Galileo in
1610 and have been a mystery pretty much
ever since
Voyager told us a lot about the Rings
but raised as many questions as answers
and as a matter of fact we’re still
arguing about how old they are the
enigmatic moon Titan Titan is a moon of
Saturn but if it weren’t for it had not
succumbed to get Saturn’s gravitational
pull it would be a planet larger than
mercury larger Thunder a moon it is
covered with a thick organic haze of
nitrogen and hydrocarbons and then
finally the retinue of not finally but
the retinue of Saturn satellites Saturn
has been busily collecting material from
all over the solar system some of it
it’s generated itself some it’s captured
from the Kuiper belt
Jupiter helps a lot it brings things in
and Saturn picks them up 62 of the most
eclectic combination of moons you’re
ever going to find and when you got to
an awful lot of them and then finally
the intense magnetic and electric fields
and dust that surround the planet let me
just walk you through a few of the
highlights of our discoveries in those
13 years before I get back to the grand
finale
first of all Saturn covered with lots of
small storms but Cassini was lucky and
got a one-in-a-lifetime
of one who’s at 30 years I should say
just a wonderful one in Cassini lifetime
opportunity the so-called 30 year storm
a monster storm that began in Saturn’s
upper latitudes raged all the way down
into the interior of the planet pulled
material out to the surface and was
churning we were actually able to
some of the interior of the planet
through this storm it persisted for
almost two years and as it slowly
wrapped its way around the planet the
head and the tail met and within a few
months the storm collapsed you can still
see it’s heat signature today but Saturn
looks exactly like it did in that
picture on on your left the North Pole
of Saturn a jet stream that is persisted
for almost 40 years and in the middle of
it a hurricane the size of France the
winds around the edge of that hurricane
are going about 540 kilometers per
second and again this is persisted it is
almost all by the way that’s not the
real colour we’ve done a little bit of
enhancement there just to keep social of
the contrasts the Rings are lettered a b
c d e f g h and they’re named in order
of their discovery but what we found in
voyager saw this first these rings are
not ABCD there’s a 1 2 3 4 5 6 7 8 9 10
and they keep on going the rings are
nothing but many many many many many
rings and they just go and go and go
it’s the closer you look the more
associated in the rings and I’ll get
back to that a minute but here’s going
to show you one of our favorite my
favorite pictures actually our favorites
every 15 years the Sun comes right edge
on to Saturn and it filled an earth the
Rings appear to disappear because they
are not illuminated but from Saturday’s
point of view you can look down over the
top now you’ve probably all seen
photographs of the pyramids at noon you
can barely see them but at sunset they
cast these long shadows across the
desert floor just what you’re looking at
here those shadows are the shadows of
big clumps in the Rings cast over the
much smaller material most of the Rings
are only a few maybe 100 meters thick
they’ve been squashed down by Saturn but
out of the edges of the B ring here you
can see things that are the size of a
kilometre massive chunks of ice and rock
so we’re able just by being persistent
to determine some of the ring structure
with the photography itself
this is one of my favorites as well just
because it’s the F ring is this outer
thin band and it’s a very tortured ring
because it’s got two little shepherd
satellites that are constantly messing
with it and you can see one of them down
there in the lower right and you can see
that little knot it’s pulled into it
there’s a constant sense of turmoil in
the F ring because as soon as you get
stable either pan or Pandora or Capri
theate Prometheus or Pandora come by and
and churn it up again and then this is
kind of fun a lot of times when we’re
taking pictures of the Rings you know
you’ll see a moon or satellite some some
a little photo bomb but this one was
particularly fun because if you look
closely at that that’s not a moon that’s
not a star that is the earth taken from
a billion miles or a billion kilometres
away and if you look closely at the
inset you can see Earth’s moon as well
so one of our favorite family portraits
everybody’s there and then Titan Titan
from voyagers point of view and from the
Earth’s point of view was just a big
fuzzy ball covered with essentially you
know the equivalent of smog I’m from Los
Angeles and I can tell you all about
that we couldn’t see through it so one
of Cassini’s missions was to penetrate
through that fog with the many
instruments that carried and understand
what was going on in the surface the
first thing we did was we landed the
European Space Agency’s probe onto the
surface of Titan and a period of two and
a half hours when we went from that to
this that is a picture from a surface of
Titan by the european probe as it slowly
paired a parachuted down to the
atmosphere and imaged the surface that’s
a dry lakebed believe it or not those
rocks are not well they’re rocks but
they’re water ice at a hundred and
seventy 180 degrees below zero so
degrade water is as hard as granite and
has taken the place of the silicates
that we expect here on earth but the
liquid is now methane and ethane simple
hydrocarbons that freeze at a much lower
temperatures and this was once a methane
lake
has since dried up oh and just for
contrast let me show you that’s a
picture of the Apollo astronauts
footprint just to give you some idea of
the size size of those rocks by the time
we were done exploring Titan thirteen
years later we discovered tight to is an
earth-like world it has rivers it has
lakes and it has seas now they’re not
water they’re ethane and methane
hydrocarbons more hydrocarbons on Titan
than there are over the entire earth if
we get a pipe up there we’d be in great
shape
dooms much like the students in
equatorial and the equatorial regions of
the United of the earth mountains clouds
and rain an entire meteorological cycle
those rivers are filled with rain they
fill the lakes it evaporates it goes on
and on and then finally as I showed you
dry it will dry riverbeds that Huygens
showed us and then here’s the biggest
surprise from Saturn all Enceladus the
Enceladus of Voyager was a white
snowball but we didn’t quite understand
the Enceladus from Cassini was
marvelously resolved by the images but
what was even more important this little
300 kilometer sorry 500 kilometer
snowball actually had geysers a total
surprise to everybody
it just seemed impossible that something
that small could be active well by the
time we were done Ravech during the
mission to explore Enceladus we had
discovered that Enceladus was indeed had
an active Jets and a subsurface ocean
over the entire moon
five hundred kilometers fairly big
enough to pull itself together and it
had notion the ocean was global the
water was salty the long-lived and there
are hydrothermal vents that water in the
ocean is hot and there’s actually enough
heat to almost boil it coming from
Enceladus it’s irrefutable the ocean is
the plenty of height of heat energy and
even more compelling molecular hydrogen
an essential ingredient for life and
you’ve got organics in the plume coming
from the ocean so you’ve got heat you’ve
got salty water you’ve got hydrogen you
have
all the components for astrobiology now
no one’s saying there’s life at
Enceladus but this has turned us around
about what Enceladus could possibly be
and where life could be and there’s a
graphic illustration of what out of what
it might look like on the surface of
Enceladus so that leaves us with the job
of protecting Saturn’s ocean worlds
which is why we decided to destroy a
discovery machine but not before we had
done the grand finale 22 orbits through
this incredible gap so I need to show
you quickly what we meant by that let me
just go you to a graphic to a poet or an
artist
Saturn is beautiful and the Rings are
graceful but to an engineer both of them
are hazards if we get too close to the
atmosphere we would tumble out of
control if we got too close to the Rings
you can see at 120 kilometers per second
we had a little chance of survival so we
had this very perilous course to try to
stay through the gap so to speak and it
was very important that we manage to
keep directory carefully so let me show
you something really kind of fun here
what we decided to do was keep the
antenna the main dish of the spacecraft
pointing into the dust for the first
travel through to see what happens so
listen to this this is what we expected
to hear this is coming through the F
rings write that chart is actually we’re
using the main antenna and then as the
particles hit it we’re turning those
into sound so you could actually hear
the increase as the spacecraft travels
through the passageway so this is what
we expected and if we got something like
this we’d be fine we’ve done it plenty
of times before no big deal so we did
this sort of thing with the first
passage through and we got this you can
see from the picture there is just
nothing going on we had to exaggerate it
even to get any sound at all so what
turned out to be something of a great
fear for the mission turned out instead
to be a great surprise
we had nothing to worry about so the
spacecraft guys were all you know
scientists got a puzzle they’re happy
where’s the desk oh we’re happy because
we’ve got no problems with going through
the gap and the atmosphere messed with
us a little bit but we we figured that
out as well so here just a few of the
final photos in those final 22 orbits
the ring satellites pan as you can see
get carving a gap in the Rings Atlas
also has carved a gap in rings and both
these have little mini skirts around
them of ring material they’ve actually
about as big as they can get any bigger
and Saturn will rip them apart and then
finally this beautiful little moon
Deafness that’s running around in the
Keeler gap and you can see the waves of
gravitational dispersions that is put on
the weight rings and let me give you a
close-up of this so fascinating these
little ripples dissipate after a little
while but they just followed after sit
around as it shuttles around through the
Rings and this is a family portrait and
I a fight a flight team is just like an
army it runs on its stomach so I
couldn’t stop them from doing this and
they do look like pierogies Hamas say
the Rings incredible resolution of the
Rings especially the straw colored
material to the left and then another
picture of the Rings showing the entire
internal history of the Saturn every
time Saturn burps or gurgles its ripples
the Rings and its entire history of
Saturn is captured in time from the
upper right lower right to the upper
left in this illustration finally the
last day Saturninus rings Titan
Enceladus setting over Saturn ice
structures within the Rings themselves
and we had discovered earlier and moon
forming on the outer ring of Saturn the
outer a ring the investigator named it
Peggy
after his mother-in-law and so he took
one last picture of Peggy Saturn
approach this is an image again an art
artistic running of the Saturn of
cassini on its final approach to saturn
it had one last job to do because if we
were really going to keep all our
promises Cassini was now going to become
an atmospheric probe we were going to
sample the atmosphere something that had
never been built to do and then return
the day to earth so we first turned the
antenna towards the earth we turned on
the instruments that could be useful at
that time we configured the spacecraft
to play everything back and then into
the atmosphere we meant the whole
strategy from then on was just hang on
stay pointed the earth as long as we
possibly could to keep the data plane
thrusters were fighting against loss of
control they were not as you can see
from this picture this is not built for
speed in the atmosphere they were
fighting and fighting and fighting
against the incoming encroaching
atmosphere and for the Larry very last
second Cassini was returning data
finally as you can see the spacecraft
vibrations became more and more
oppressed by the atmosphere and it
wasn’t long before the thrusters gave up
we lost contact with a spacecraft
shortly thereafter we lost contact
destroyed became a part of the very
planet it was sent to explore safely out
of harm’s way
it entered Saturn and was vaporized this
is again an artist’s rendering of what
we think was probably Cassini’s last
view as it went into Saturn 15 years I’m
sorry 13 years of exploration the
spacecraft finally ended but not before
it had opened our eyes and revealed an
incredible world a world that has
rewritten and rewritten again the text
on planetary exploration and planet
formation it has made us rethink what we
have to do what we what we think about
astrobiology and it just begs us to come
back again it’s a tribute to the
international effort and the might of
the the world’s people in getting this
thing off the ground and again revealing
the universe to us all if he’s thought
[Applause] [Music]
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