**FTS-NASA-VOICE**

**Moderator: Trina Ray**

**June 27, 2006**

**1:00 pm CT**

Coordinator: Excuse me, this is the operator. I just need to inform
everyone, today\'s conference is being recorded. If you have any
objections, you may disconnect at this time.

Ms. (Jones), you may begin.

(Jean Jones): Thank you. And I\'m going to turn it over to (Dave Seal).

(Dave Seal): Okay. Thanks, (Jane).

Okay. We're...

...now. This is - again we had a nighttime launch on October 15 of 1997
from Kennedy Space Center. We spent nearly seven years cruising to the
inner solar system. What we launched really an enormous spacecraft that
was packed with instruments covering the entire electromagnetic spectrum
as far as observations that we can accomplish. Because the Spacecraft
was so big and so powerful, the largest spacecraft that was really
feasibly at the disposal of NASA could not launch it directly to Saturn.

We used the planets of the inner solar system; first, Venus twice then
the Earth and then a small kick from Jupiter to get us out to Saturn.
And it's - it really offered us a great advantage because it - using
those - the inner solar system planets really allowed us to send this
enormous and really capable spacecraft to Saturn whereas we would have
had to send something much smaller to go there directly.

You can see from the graph on the right the trajectory that it took to
get us out to Saturn. We launched sort of near the middle bottom below
the Sun there. Again on October 19, 1997, we followed the green leg
until our first Venus flyby which is in June of '99, about quite two
years later.

We then had a long leg out almost near to the orbit of Mars, executed a
deep space maneuver near the end of 1998 and then came back for a rather
quick Venus to Earth leg.

The second Venus fly - Swingby, you can see sort of near the - to the
upper left of the Sun was in June of '99. And then we had an Earth
Swingby below the Sun there less than two months later in August of '99
which is a very interesting and intense period for us.

We\'ve made it out to Jupiter and had a lot of good scientific
observations at Jupiter near the very end of 2000. And after about three
and a half years of -sorry, in July 1 of 2004 was our arrival at Saturn.
So we\'ve been at Saturn for nearly two years. And hopefully the rest of
telecon you can get a feel for all the great (unintelligible) today.

Page 3 is an illustration of the Cassini spacecraft. Most of what you
see here is actually covered with thermal blanketing called - which is
gold in color and called capton. But that blanketing has been removed
for this image so that you can see a lot more of the hardware that
composes this Cassini spacecraft. Again, the Huygens antenna and much of
the communication systems there at the top. We\'ve got an 11-meter
magnetometer boom that\'s extending out after the end of the screen - at
the end of the screen to the left.

Some of the instruments are illustrated here. We've got a dust analyzer
that's on the left side of the spacecraft in this view as well as the
most of the remote sensing instrumentation which is sort of on the front
of the spacecraft from this view.

There's a fills and particles component on the right. You can see just
below the Huygens antenna the sort of 12-sided structure which contains
all of the - nearly all of the electronics, all of the - both strings of
the main computer as well as the other two control computer, all of -
most of the Cassini instrumentation is located here, if it's not in the
instrument itself as well as all the data processing function and
storage.

Near the bottom on the spacecraft, you can see three radioisotopes
thermoelectric generators. These provide us with just under 700 watts of
power right now. We lose about 1 watt a month just from the process of
how the radioisotopes undergo fission. But it's really more than enough
power to operate the instruments in different suites of modes that are
appropriate for whatever observations we're taking.

At the very bottom you see, we have 200-pound engine; that\'s about 490
newtons. They're redundant and these engines are used to execute all of
the major maneuvers of the spacecraft.

Again the spacecraft is enormous. It's really the size and weight of a
decent-sized school bus. And because we were able to use the inner solar
system planets, we've been able to launch all of these great instruments
to make sort of coincidental if not simultaneous measurements of all the
interesting features of this (journeying) system.

Our solid state recorder is half a gigabyte. It's about the size of what
you can store on a CD which may not seem like a lot nowadays but when
the spectrum was being designed in its final stages in the early to mid
90s, it was an impressive amount of data.

And because we download to Earth everyday, you know, we can - if we
choose and if the size of the observations permit, we can fill this
recorder everyday and empty it everyday and collect really a staggering
quantity of data about Saturn.

On Page 4, this is an illustration of all of - nearly all of the bodies
the...

...the Saturnian System that we\'ve discovered to date.

On the top you can see illustrations of the various satellites that
we\'ve discovered. These are nearly altered scale. There\'s a handful of
that have asterisks after them which are rather small and the size of
them had been exaggerated. But you can see from the top that Saturn
really is almost a solar system in and of itself. It's got a large
number of moons that span a wide range of diversity in terms of surface,
features, and appearance and size.

On the bottom half of the chart, you can see at least for the first half
a dozen or so major satellites. You can sort of see what their...

...are from Saturn.

You'll also see illustrated here where the different spacecraft that has
visited Saturn across through the ring plane and made among other things
(unintelligible) measurements of those point.

You can see beyond the main rings of Saturn there are two fainter rings,
the G ring and the E ring. The brightness of those rings in this
illustration depending on your computer screen may look very
exaggerated. But it's an illustration to show sort of where in the
Saturn system they're located.

Okay. Going on to Page 5, again, we're half way through our four-year
prime mission. The prime mission in total is 75 orbits, 45 targeted in
which using means close and it usually means that there\'s a very
concentrated suite of observation that's planned for that time period.

So there\'s 45 targeted Titan flybys, 8 targeted flybys of the other
satellite - the icy satellites of Saturn. And there are many dozens of
more distant non-targeted flybys and observations that we also have.

Our science objective are split into five major themes: Titan, Saturn,
the ring, the icy satellites, and the (rings) this year. There\'s a lake
here. I think the one at the bottom at least on my chart is the one
that's fully delineated. The other one - the one hat\'s kind of moving
may be cut off depending on what chart you\'re looking at. But there are
some great (moves), not only in the chart link but also in the lake
that's (unintelligible).

And the - what we call with some humor, the spaghetti pot, you can see
there on the right sort of shows - is an illustration of how diverse
our, you know, our obits are. Each orbit is really unique from the other
ones. And by this spaghetti pot, you can see that we really tour nearly
all of the regions of the Saturn system in our four-year tour.

Okay, Page 6. Our orbited systems are performing normally. The
spacecraft is - has really been frighteningly healthy with really almost
no anomalies or problems to speak of. All of our consumable usage, how
much fuel we've used, et cetera, how our power has trended are either
running according to the predict or actually doing considerably better
than we expected. Our use of hydrazine which is our - fuel we use for
small maneuvers and altitude control is really running quite a bit
better than we'd expected. And we anticipate having at least half the
take left-over for any extended mission that we can do after the four
years are over.

We just completed with what we call the occultation phase and are about
to begin the magnetotail phase of the mission.

Again occultation is where Saturn passes in front of a body usually
either the Sun or the Earth or a star and the rings as well. And by
measuring the single strength from the source, you could tell a lot
about the various (unintelligible) just treading the Saturn atmosphere
as well as the rings.

What we're doing now instead of rotating the orbit out to the
magnetotail which is the direction that's opposite the direction from
the Sun if you\'re looking at Saturn. The rings of Saturn again
(unintelligible) during the mission which is why we\'ve done the
occultation - some of the occultations early in the mission particularly
over the summer of 2005. And we\'ve had some equatorial orbits that we
used to do like the satellite flybys. And again now we're rotating to
magnetotail to continue on with other teams of science observation.

Fourteen orbits have been completed against 13 targeted flybys, 45
non-targeted flybys which are about 100,000 kilometers or less to date
as you can see at the bottom of Page 6.

Page 7 is a bit dense but it's an illustration of sort of what the
various activities are during the mission.

At the very top, you can see that's - those are targeted encounters
where the letter indicates the name of the satellite. The orange Ts are
for Titan. We're pretty much in the middle of this plot so you can see
that there are a lot of - a lot of Titan flybys have been executed to
date as well as most of the targeted icy satellite flybys \-- those are
the blue letters \-- starts with CD to the left. You can see we\'ve had
some Enceladus encounters as well as some closed Hyperion which is the H
and then Dione and Rhea.

The next section down is sort of the non-targeted encounters and you
could take that the two letter - the one or two letter identifiers and
connect them with the satellite name that was listed on Page 4.

There\'s a middle part that shows occultation. You can see there was a
rather dense period of occultation from the Ts and the Ss in the summer
of 2005. And then you\'ve got sort of an orbit plot that shows distance
from Saturn with time. You can see on the next plot down that our
inclination was very low up until about now and where - once we reach
the magnetotail, we'll start raising the inclination you can see sort of
in the late summer and early fall of 2006. So until we reach an
inclination of about 50 degrees to 60 degrees for about six months
centered on that the new year coming up.

On to Page 8, again here\'s our - here's the second year targeted flyby
summary. We started with targeted Enceladus encounter in July of 2005.
We went on for icy satellites to get close to Hyperion, Tethys, Dione,
and Rhea. And you can also see there were like nine targeted Titan
flybys as well in the second year of the tour.

Let's see. To date, on Page 9, we\'ve returned a large amount of data,
60 gigabytes. We\'ve done a number of trajectory tweaks to account not
only for retargeting and gaining some icy satellite encounters but also
to account for Titan's atmosphere being somewhat denser that we
expected.

None of these trajectory alterations have significantly degraded really
any - major - any measurable aspect of the mission. And a number of the
tweaks in fact have actually given us enhancement that that's why we\'ve
done some of them.

A lot of the work we\'ve done in the last few months has been focused on
preliminary planning for the extended mission. We had a lot of
discussion in France \-- most of the science community \-- about what
the priority should be based on what we know now.

We\'ve - we have initial inputs from all of the instruments and all of
the disciplines. We have nearly a dozen tours that have been - sample
tours that have been released for people to look at and study.

Man: You\'re going to be late.

(David Seal): We had some consensus in a number of areas that was good
at the June Project Science meeting and we'll continue on with our
future science meetings in October and then in 2007 to refine our plans
for the extended mission.

That concludes the mission overview section. We're at Page 10 right now.
And if there are any questions, I'd be happy to take them.

(Ken Kramer): Yeah. Hi. I got a question. My name is (Ken Kramer). I\'m
an ambassador from Princeton.

(David Seal): Hi (Ken).

(Ken Kramer): Hi. My question is just about these tours. Do they vary
greatly? What would be the significant differences in them?

(David Seal): Yeah. For the extended mission tours, you know, the trade
space for what science priorities we go after for the extended mission
is still very wide open. We're trying to focus the effort now and
that\'s - we\'ve made a lot of good progress at the science meeting in
France.

But the tours to date have really spanned almost every corner of the
Saturn system and some of them state high inclination above the ring
plane and some - and many of them came down to the ring plane and
rotated in various directions.

So there really were very few limits placed on the tour development to
date. But I think we got a lot good input and we'll be focusing on a
rather smaller subset of tours from here on. And our goal is to select
for the final tour and pretty much have it ready in May of next year. So
we\'ve got, you know, about 10 months to complete all of this work and
study.

Okay. Any other questions?

(Matthew Otto): Hello. This is (Matthew Otto) with the Saturn
Observation Campaign.

(David Seal): Hi (Matthew).

(Matthew Otto): Yeah. My question is on its high inclination orbits and
I noticed that they are very eccentric orbits. I wanted to know if the
imaging team will be giving some images of Saturn's atmosphere in the
polar region and studying the circulation of the (unintelligible).

(David Seal): Okay. I think I'll let Andy or Elizabeth answer that one.

Andrew Ingersoll: The answer is yes, of course. But I'll tell you about
it in half an hour.

(Matthew Otto): Okay, very good. Thank you.

(David Seal): Great.

Okay. If anything, I probably went a bit late. So on to the next
presentation which is Dr. Andy Ingersoll from Cassini Imaging Team.

Take away, Andy.

Andrew Ingersoll: Hi there.

Everyone turn to Slide Number 10.

This is March 10, 2006 issue of Science Magazine which had a suite of
articles from different instrument teams devoted to Enceladus.

Enceladus was discovered in 1789 by William Herschel. And it's a
500-kilometer diameter moon fairly close in to Saturn. There\'s a bunch
of little moons that were discovered in the twentieth century (in
closer). And there\'s one William Herschel-type moon, Mimas, inside
Enceladus. But it's pretty close into the planet.

And the amazing thing is how active it is. It's filling out material,
it's warm, it's internally heated, geologically active. And that\'s
amazing for a cold little object in the outer solar system. And Cassini
really learned a lot about it. And that's what I\'m going to tell you.

So move on to Slide 11.

This is a voyager image taken in 1981. And it excited a lot of people
because you see that sort of craterless area - well, there are a number
of craterless areas but there - one in particular that sort of goes up
like a hour hand pointing towards 12, it looks like something slowed out
on the surface and partially covered some of those craters. The fact
that there are so few or even no craters on that slow feature means that
it's geologically none and that means probably it's - inside it's
geologically active.

So even in 1981 people were excited about it. At the time, the candidate
for the flowing liquid was an ammonia water mixture which stays liquid
down to almost 100° - minus 100°C.

Let's move on. There were other hands though. Slide 12 shows an edge-on
picture of the ring system. The A, B, C rings are overexposed in this
picture. It was taken from Earth as the Earth and the Sun were going
through the plane of the ring which minimizes the light from the A, B, C
rings. But then you see the E ring and G ring.

Now the E ring has its mass and density right at the orbit of Enceladus.
And this is suggestive that Enceladus is giving off particles in some
way - one way or the other. And that's further evidence that it's active
in some way.

The last evidence before Cassini really has its close flybys is Slide 13
where you see atomic oxygen that\'s just neutral oxygen atoms floating
around the two ellipses there. The inner one is the orbit of Enceladus
and the outer ones the orbit of Dione. And you can see that the
brightest - the maximum amount of oxygen is right there at the orbit of
Enceladus.

But hydrogen is also detected there and OH are simple sort of water-like
molecule without missing one hydrogen has also been detected there. So
this suggests that water itself is being released from Enceladus in some
way or another. This is also - I believe 2004.

Moving on to Slide 14, in early 2005, the spacecraft made a few sort of
close but not too close passes at Enceladus. And the magnetometer in
particular, detected some distortion in the magnetic field. And the
distortion was rather peculiar. It has a signature of an ionized plasma
in the vicinity of Enceladus, some kind of electrical conducting gas.
But it wasn't centered on Enceladus; it was centered off to the south of
Enceladus as shown in Slide 14.

And so that was interesting enough that the people who actually run the
spacecraft were willing after they saw this data to change the orbit of
the spacecraft so that we took a close flyby of Enceladus right over the
south pole or south of the south pole and - to go through this plume if
it was indeed a plume. So that close flyby was done on July 14, 2005.

And this - now on Slide 15, you can see some of the discoveries. This is
the imaging system. And with the geometry of both of these images is
that the sun is almost behind the satellite. So you're seeing a very
thin crescent illuminated and the rest of the satellite is dark.

And emanating from the crescent are these little streaks of particles,
streams of particles. And when you overexpose the image you can see that
they're going off several radii away from the planet, the little streaks
in the (images), stars, from the (long) exposure. But you can see that
some of the particles are just leaving the satellite altogether. So
there are plumes, there are geysers, some kind of jets on Enceladus
which is amazing just in and of itself.

Slide 16, if you're looking at the PowerPoint, you will actually see
motion here. As far as we can tell, the motion is due to the motion of
the spacecraft and we took several images that was receiving a ray from
Enceladus. But by looking at these four images over and over, we are
able to tell where on the surface of Enceladus these jets are coming
from. And that's in the next slide.

This is - they're coming from the south polar region. Some of the best
determined ones are A, B, and C. And you can see they're coming from
this crack down in the south polar region which is a little trough about
2 kilometers wide and 400 meter, 500 meter deep. And so the jets are
apparently coming from the trough which we - for some reason someone
named "Tiger Stripes."

Here's the whole picture, Slide 18, of the south pole. The south pole is
right in the middle of those stripes. So - and they are indeed blue.
They're basically the blue color of a block of ice and the implication
is that they are rather large by our standards, maybe the size of sand
grain, ice crystals near these tiger stripes which are as I told you the
source of the plume.

Now you can also see sort of surrounding the tiger stripes, there's a
sort of polygonal pattern of strange cracks that - when we look at them
closely, this sort of a polygonal pattern that surrounds the south pole
is a compressional feature and then you'll see cracks that emanate all
the way up north right off the edge of the planet. Those are extensional
features. They sort of cross the equator actually.

And next slide, Slide 19, shows you red - a view right looking state
down on the south pole. Red is the compressional features and blue are
the extensional features. This is the kind of cracking pattern you'd get
if the satellite were spherical at one point and then became flattened.
But we don't quite know why that happens but it certainly looks as if it
(dipped).

The tiger stripes themselves are more mysterious and we don't understand
them. There are no tiger stripes in the north pole which is a further
mystery. But of course discovering mysteries is want we to do in this
business and then we want to solve them.

Slide 20 shows the crater density on various places on Enceladus and you
can see that there are some places that are heavily cratered. And the
lowest curve is the area of the tiger stripes and there's actually no
craters in this size range in the tiger stripes. That lowest curve is
just the upper bound. And from the absence of craters in the vicinity of
tiger stripes, you can infer that that surface has been resurfaced in
the past few million years which is a very short amount of time on
geologic time scale.

But we did take some very close up images and Slide 21 shows you our
best one of the area near the tiger stripe. The resolution here is about
2 meters per pixel. And these lumps that you see here are maybe 10
meter-sized boulders. We have no idea what they're doing there; how they
got there. I'm sure some of my friends in the imaging team have theories
but they were surprised and they were quite mysterious.

I told you that these plumes are extending off the planet. That's the
next slide. Let's move on from that one.

There are other instruments - so Slide 23 shows you what the ultraviolet
spectrometer did. They watched a star \-- two stars, actually \-- the A
and B show the path of one star as it apparently - I mean of course the
star wasn't moving but the spacecraft was moving so the star appeared to
move behind Enceladus. And that's the path that the star took and shown
in A and C and D showed that the path the second star Gamma Orionis
took. And you'll see that the D that the star passed right through the
plumes emanating from the south pole.

And so looking at how the starlight was absorbed...

Man: (Yes).

Andrew Ingersoll: Yeah. Looking at how the starlight was absorbed became
very interesting because we're able to measure the - to see the spectrum
of that absorption and determine what the plumes were made of.

The next slide which is Slide 24 shows the spectrum; this is
ultraviolet, some 1,200 angstroms to 1,800 angstroms. The light curve is
the spectrum of - that we've measured; the absorption of that starlight
and the heavier curve is the spectrum of water vapor. And you can see
over on the left around 1,200 angstroms, it matches water vapor very
well; it also matches the long undulation off to the right. And it
actually represents a certain amount of water vapor in the path between
the instrument and the star. And so that's another hint that these
plumes are made of water.

Next slide, Slide 25, is the result of the - another instrument which is
the Near Infrared Mapping Spectrometer, NIMS, and they also take spectra
and they find evidence of water, ice all over the satellite.

They also - if you look down at the center, 3.44 micron organic
absorption, that's really - they can see the spectrum of the chemical
bond between carbon and hydrogen. And you'll notice that that chemical
bond shows up in some kind of organic molecule; could be methane, ethane
or (benzene). It could be a lot of different things. Some kind of
organic molecule shows up in the region of the south pole and in fact it
aligns with the tiger stripes. So you got organic molecules, you got
water, and pretty interesting stuff.

Now those are remote sensing instruments. Turn to Slide 26 and you'll
see the path of the spacecraft as it flew close to Enceladus. And there
were several instruments that samples the medium that they were flying
through not (unintelligible) measurement. The INMS is a - measures the
molecular weight of molecules and identifies their composition that way
and CDA measures particles and measures their size (distribution).

Now moving on to 27, you can see the molecular weight of the molecules
that the INMS instrument and if you recall your Chemistry, the biggest
peak there is molecular weight 18; that's oxygen which is 16 plus 2
hydrogen, that's 18. That's water, hey.

Then the big peak over to the right is mass 44 which is a carbon and two
oxygen. A carbon is 12 and each oxygen is 16, so that's mass 44. So they
were detecting carbon dioxide as well.

In the third peak is mass 28 which is ambiguous because it could be two
nitrogen, 14 plus 14 or it could be carbon monoxide, a carbon and an
oxygen. But carbon monoxide was not seen anywhere else. So our thinking
is that it's nitrogen, N2

You also notice that the water peak at mass 18 has sort of a shoulder
down to 16 and that's probably methane (CH4). And so it goes, but
further evidence that the plumes are reaching the altitude of the
spacecraft that there's water and CO2, Nitrogen and some organic
molecules or even evidence of acetylene, C2H2, and propane (C2HO).

Okay. Slide 28 shows the results of the infrared radiometers (here). And
another amazing thing about the tiger stripe is that they are warm. You
got to remember that this is the outer solar system and sunlight can't
warm the south pole up to 85° K It's got to be some kind of internal
heat and - but yet, overall large area around the south pole, Figure A,
shows you this - that bright patch is right centered on the south pole
and it's 85° K.

But there's more. If you examine the spectrum of light coming from this
hot patch - warm patch, let's call it, the spectrum does not fit a
(black body) at 85° Kelvin. It's got a component of that emission coming
from a small area in that south pole region that's a lot hotter and so
over at least you can see the probable temperature that small component
within the field view and it could be a 135° Kelvin.

Slide 29 shows when we got even closer and scan right across one of
these tiger stripes, look at C there near the bottom, we got up to 90°K
in the field of view which is represented by the little box, but when
you look at the spectrum, so this could be over E, you can see that
there's a component there occupying a few percent of the area that's
probably 145 °Kelvin which is much hotter than sunrise could possibly
produce and implies quite an internal heat flow coming up from inside
the satellite.

That internal heat flow implies a temperature greater inside the
satellite. In other words, it has to be warmer inside than the surface.
And you can ask, okay, if it's getting warmer as you go down, that's the
temperature grade then that's needed to supply this internal heat.

If it's getting warmer as you go down, how far down do you have to go
before it's 73° Kelvin? Well, that's the melting point of water. The
answer is 10 meters. So just from this thermo conduction argument, it's
very likely that at least in - underneath these cracks or at least some
small part of them, there's liquid water in some crack 10 meters down.
We don't know that for sure, but it's very hard to escape it.

Now the next slide is Slide 31 which is sort of a cartoon of all that. I
really have two things to say. This is my last slide, I believe. One is
you've got liquid water near the surface. You've got some communication
to the outside. You've got a hydrologic cycle. Therefore, you've got
chemical energy, you've got organics, you've got liquid water. It makes
Enceladus an interesting place to consider the possibility of
habitability and the possibility that life possibly could have developed
here.

So that's entirely speculative. The mystery - I think the biggest
mystery is what maintains all these activities? Where did the energy
come from? What keeps the interior hot and we don't know. Our best -
maybe not our best model but the models that we have in our libraries
before we went by Enceladus says that they predicted about 10% of the
amount of heat that we see coming out of the south pole. And - so we're
still of by order magnitude in explaining what keeps Enceladus hot.

And the last slide says, "The End" but it's not the end because we are
going to go on observing Enceladus. We're in orbit around Saturn and we
can get to plenty of chances and it's going to be an exciting time.

Now I - some of - if you go to the - don't go, but after this talk is
over and everyone is done, go to the very back of the presentation and
you'll see some written notes of mine.

And with that, I would like to - I think in the interest of time, I
won't ask for questions. But I'd like to introduce Dr. Elizabeth Turtle
who's an associate of the imaging team and will tell us about icy
satellites. Her name is Zibby.

Elizabeth Turtle: Thanks, Andy.

So the icy satellite portion of the presentation picks up Page 32 with
just a summary of information. And in the interest of time, I'm just
going to skip through to the actual slides about each of the satellites
that we've had close targeted or these targeted flybys in the past year.
There were several flybys. They were quite close to a number of the
satellites last fall; so that's been very exciting.

The first one which is actually rather distant flyby but it was the
closest we'll get to Mimas during the nominal tour was last August. And
Mimas in stark contrast to Enceladus is a very old heavily cratered
body. It's a little closer to Saturn than Enceladus but not (a lot) and
they're about the same size...

Woman: Yeah.

Elizabeth Turtle: ...It's a little smaller than Enceladus.

Woman: Less than to it.

Elizabeth Turtle: So that contrast is very interesting. You can see by
the various images on Slide 33, the heavily cratered surface and the
large - the one large 140-kilometer diameter crater Herschel.

The formatting on some of these slides is actually in the transition.
Somehow things got a little messed up. So I apologize to the (types) of
the texts in some of the new - is white on white or in fact over some of
the images. But hopefully there'll be enough that's visible to make
sense of it.

The next close flyby of one of the satellites was at the end of
September. There was a close flyby at Tethys. This is Slide 34. Tethys
is much larger than Enceladus and Mimas and is also a very ancient
satellite. You can see in the upper left an image the Odysseus crater
which is a few hundred kilometers in diameter. And on the upper right,
there's an image of (unintelligible) which is a huge several kilometer
deep fracture that runs most to the way along - it runs about
three-quarters the way around Tethys.

And this is one of the - a view of an area that Voyager hadn't seen and
with the observations that we've gotten from the various flybys of
Tethys in the past year, we're getting more information about the status
of that.

Now you can clearly see here that even though it is fractured, it's a
very old surface there; a lot of impact craters on that fracture \-- on
that large fracture.

In the lower left is a much closer image of Tethys. And you can see that
there's - in some of craters there's been landsliding or slumping of
material down on to the floors. So it's - even though it's an ancient
cratered surface, there has been some modifications since the craters
were formed.

Right after the Tethys flyby, there was a very close flyby by a small
irregular satellite called Hyperion. And on Slide 35 are a couple of the
images from that. Hyperion is a very dramatic surface. It looks
completely different from anything we've seen in the solar system. And
it's just very strange.

It looks like there's very dark material that's concentrated in the low
areas in the bottom of some of the craters. And there's a lot of - you
can see in the image on the left which is the whole of Hyperion that
there are a lot of craters that are formed on slopes that have been
degraded.

It's a fascinating surface. There's a very high resolution mosaic on the
right hand side of the slide that shows a strip across the surface and
some of the details which is the - there are in fact some very small but
bright craters within the dark material which can help us constrain the
thickness of the dark deposits on the bottom of those craters.

At the bottom of the slide, there's actually a couple of links. There's
a movie that kind of pans across some of the images of Hyperion and I'm
not going to show that here. But there are links to those movies listed
there. It's kind of - it's a dramatic view of the surface.

The next close flyby which is a couple of weeks later in October and was
a very close flyby of Dione which again is one of the middle-size
satellite. Now Dione is - you can see on the upper left is an image of
Dione that has craters. But there's some parts of the surface that are
not heavily cratered.

So it looks substantially different from Tethys which is about the same
size. There's some areas that are fractured and faulted and during
this - very early part of the Cassini mission, the wispy terrain you
kind of see in the color image at the top and a little bit on the image
at the right, was demonstrated to be fractured.

During this very close flyby last October, we actually got very close
views, very high resolution views of these fractures and some of those
are shown at the bottom and you can see the bright fractures cutting
across the craters there.

And in fact, if you look closely at the one on the bottom left, which
unfortunately is covered because the text gotten (around) in the
formatting, the bright irregular fractures that run from kind of the
upper right down to the lower left and then there's the set of really
fine dark fractures that run fairly straight from upper left to lower
right. And so we can see that there - and not only are fractures on the
surface but they're multiple generations of fractures.

So Dione clearly has had some level of activity, of tectonic activity
much more recently geologically than some of the other satellites like
Tethys.

And very intriguingly, the magnetometer on Cassini found a signature
similar to the signature that it found near Enceladus. Now it's a much
lower level and there's only been one flyby that they've had that -
there's only been one close flyby of Dione; so we need to look into this
more. But it's very intriguing that there may be more to Dione as well.

Then in November, there was another very close flyby of the satellite
that's on - close to Rhea. And Rhea is another very ancient surface. You
can see a number in the upper left, there are a number of large impact
basins on the surface. And in the lower left is a very high resolution
image form this flyby that shows of craters upon craters on the surface.

There's also - the image on the upper right shows a bright-rayed crater.
This means that the crater was formed very recently and there's still
deposits that were - of material that were thrown out during the
cratering event strewn across the surface. These tend to fade with time
and you can see that most of the craters don't have this kind of rays
around them. But this one young one does and the image at the lower left
is actually the rim of that crater which is about 50 kilometers in
diameter.

So you can see the very...

...of that crater. And in fact, you can see superimposed upon it, a lot
of little craters as well. These are probably secondary from an even
more recent impact.

And the last slide I have for the satellites that aren't Enceladus or
Titan that we've encountered in the last year is just a set of images of
the best views we've had to date and in many cases during the entire
plan for the entire nominal mission of a lot of the smaller satellites
of Titan - of Saturn, excuse me.

In the upper left is Pandora which is one of the F Ring shepherds. And
the upper right, there's an image of Venus. And in the distance - so
there's Venus and then the rings and in the distance is Prometheus which
is the other F Ring shepherd.

The bottom sets of images, Calypso is the one at fairly resolution on
the left and this is one of the trojans of Tethys and Telesto which is
the other trojan of Tethys on the right. And they were - a number of
fairly close flybys for these satellites and intriguingly, they all seem
to have fairly smooth surfaces as if material has been mantled by
material that's been deposited on the surface and it's kind of smooth...

So I'm going to move on to Titan now. I have to talk about Titan
surface, the observations we've made at the surface from last year.
Slide 39 is again just a kind of overview of information about Titan.

And Slide 40 just lists the Titan encounters we've had so far. There
were several and in the first year - in Cassini's first year at Saturn.
In the last year, we've had another nine. And in fact, in the next year,
there are going to be 19 flybys of Titan. So it's really ramping up
the - how quickly we have to turn around between flybys of Titan.

Slide 41 just shows what Titan Looks like to the naked eye on the left;
mostly we see is its atmosphere. But if we look in windows in methane
which is one of the components of Titan's atmosphere in the near
infrared and in infrared, we can see down to its surface. And so those
two views are just what Titan looks like in the near infrared at 938
(nanometers) and then to the - (two colors).

With the imaging system, we've been building up a map of the surface of
Titan. And based on the observations of the various instruments of the
circus, a number of names have been suggested for features on the
surface.

And so Slide 42 shows a - shows the map we have so far. Now you'll
notice in the bottom where there's actually a (unintelligible) grid over
the map that just cuts off at about 30 North. And that's because it's
still northern winter and so the illumination near the northern
hemisphere - in the upper northern hemisphere is still not sufficient to
image well there. So the map we'll be getting - we'll be extending
northward as we get closer to northern spring.

The next slide shows a map of the surface made by the visual and
infrared mapping spectrometer. This is a color map using three of the
windows in the infrared. So this is full of colors because each of these
windows is in the infrared but it shows that there are spectral
variations on the surface. And at this point, there's a lot of work
going on to try to identify what those spectral variations mean.

Man: What slide number please again? I'm sorry.

Elizabeth Turtle: I'm sorry. This is Slide 43.

Man: Thank you.

Elizabeth Turtle: Bu the fact that they exist is significant. There's a
lot of material, is likely to precipitate out a lot of complex
hydrocarbons are likely to precipitate out of Titan's atmosphere because
of chemical reactions in the atmosphere. And so the fact that the whole
surface doesn't look completely uniform, indicates that material is
moving around and that there are variations on time scale shorter than
that material is falling out of the atmosphere; so on the tens of years
time scale which is very intriguing.

Slide 44 and 45 show better views of the - 44 is a (unintelligible) in
hemisphere. And these - I've over - these ones that we've overlaid names
on; these two images.

You'll see in the equator there, a lot of these regions that have a lot
of very dark areas and bright areas that mid latitude there actually is
less variation in the albedo of the surface.

You can see the same thing in Slide 45 which is an image that was
taken - a mosaic that was taken last October. Again, it's a higher
resolution view of the (unintelligible) equatorial region.

There in the - so far, the mission there has been a handful of flybys
with radar synthetic aperture - synthetic aperture radar observations.

And slide 46 shows those data superimposed on the map of Titan. The blue
map in the background is actually from HST because as I mentioned, we
haven't seen those areas well yet with the other instruments because of
the illumination. And the (gray) map is that same ISS map, the imaging
map from Cassini.

So there are five strips of the star across the surface and I'm going to
speak to T78 and T13 which are the ones that we have acquired in the
last year. The T7 is actually a very southerly path. You can see it just
on the lower right of Slide 46.

And Slide 47 shows some close up of the radar data there. These are -
you can see in them channels running across the surface. And you see
that the morphology of the channel changes which is very intriguing
because that is controlled by the style or precipitation for example and
the material properties of the surface that's being eroded by the liquid
flowing across the surface.

And the radar team actually had prophesized that the boundary that one
can see in the lower image on Slide 47 where it's bright on the left
hand side and dark on the right might actually be an ancient shoreline
of sorts.

I should say that in all the time that Cassini has been at Saturn, one
of goals is to try to look for liquids on the surface of Titan. And so
far we haven't done any conclusive evidence with Cassini of liquids on
surface.

And in fact, moving on to the next slide, the T8 observation, this is
Slide 48, this is - this covers the very dark region on the
(unintelligible) Saturnian hemisphere.

And full of what had been identified early on in the - one of the
earlier radar (patterns) as they've been described as cat scratches.
These linear, dark linear features that run across the surface. And the
T8 (was) - here really demonstrated that these are (deemed) running
across the surfaces of Titan, longitudinal beam. So they are actually
going in the same direction as the prevailing wind direction.

And these dominate the very dark areas on the surfaces Titan. So rather
than being seas of liquid, they've been described as seas of sand. Now
of course it's not sand as we're familiar with it. It's a sand-size
particle perhaps but not made of silicate but made of ice or hydrocarbon
particulates.

On a lower - the lower right of this slide, Slide 48, you can see that
there's actually change of bright features. And these are a topographic
high, a few to several 100 meters high and so that may be suggestive of
a tectonic activity on the surface as well.

Also on T8, part of that (unintelligible) actually was extended to -the
radar observation was extended to actually cover the Huygens landing
site.

And Slide 49 shows some images of a - some images showing that
comparison. On the upper right for example you can see the mosaic from
DISR, the Descent Imaging Spectral Radiometer, on Huygen's overlaid on
the radar (SWA).

And you can see a little above half way up that image, there are two
dark lines. Those are actually two cat scratches or two of these
longitudinal dunes and it turns out that these are actually
(unintelligible) as well which is really neat.

The two panels in the upper center actually just show where the landing
site is within the radar (SWA). And then I included a couple of images
more recently processed by the DISR team. The one on the left shows the
moon in a similar perspective to those images that Huygens returned from
the surfaces - the surface of Titan.

And there's been a lot of - the center - the one on the bottom center
shows some (stereo) data. There's been a lot of detailed analysis of the
Huygens data and its - the surface. There are serial pairs that show
that the surface is very rugged. The slopes in between these channels
are 30 degrees. It's about the angle of repose and the topography in
there is a few hundred meters high.

There are a number of videos in fact that Huygens has - that DISR
released in the past month or so. And I put links - the URLs to link to
some of those at the bottom of this slide.

The most recent radar path is T13 which is just a month or two ago. And
this actually covered Xanadu; the bright region that was actually
identified about a decade ago in ground-based observations of the HST
observations of Titan surface.

And this is a fascinating (unintelligible). It compare - it's - again,
showed the channels on the surface in a very rugged area. In fact some
of the results that were presented at the meeting last week suggested
that the surface has topography similar to or slopes similar to those
observed by Huygens. It's kind of 30-degree angle of slope - angle of
repose slope but more height; so several hundred meters to kilometer
height. So it's a very rugged region.

One of the other things that's really fascinating about this is it
provides one of the best comparisons we've got between imaging data of
the surface and the radar data of the surface.

And there's a link again on this. There's a URL listed there that shows
a comparison between Shikoku Facula and (Guavanito Facula). Guavanito is
a ring and Shikoku is the region that we've been referring to as Great
Britain for quite a while.

And it's really fascinating. In the interest of time, I won't go through
that here but it's really fascinating to see how the observations are
different and similar. There are some places where things are bright,
are bright in both, and there are some places where they're not,
specially including a circular feature that appears in the radar in
Shikoku Facula but doesn't appear in the near IR observation.

So that's going to be very helpful in trying - in terms of trying to
understand the surface of Titan.

So that was a bit of a whirlwind but hopefully you got a flavor of what
we've been discovering on the surfaces of the satellite from the past
year.

And I will turn it back over to Dr. Andy Ingersoll to talk about Saturn
and Venus here.

Andrew Ingersoll: All right. My computer has frozen up here. But the
first slide, you can see it Slide 51, some Saturn facts.

The most interesting fact that I want you to think about that Saturn,
the third bullet from the bottom, Saturn as a density less from that of
water which means that it's made out of very light weight stuff.

In fact it's made out mostly of hydrogen helium. It's a big ball of gas,
in fact - and Jupiter are called the gas giants because of this - the
fact that they're made out of gas. Add some other things inside like
water vapor and methane and ammonia but the main constituents are
hydrogen and helium.

And the cloud patterns that we see have this banded appearance, all
lined up with the latitude and longitude which means that the rotation
of the planet is controlling the pattern.

And we measure the wind relative to the inside of the planet, just the
way we measure winds on earth relative to the solid planet. We have to
find some reference frame to measure the wind and the reference frame
that's been in use since the Voyager time has - says that the cloud
motions that we see make Saturn the windiest planet in the solar system.
But that whole subject is up for grabs and it's shifting and Don
Mitchell will tell you about that in a few minutes.

Let's move on to Slide 30 - 52 and in fact let's move to Slide 53 which
shows the same thing. On Slide 53, which is not numbered, you can see on
the left is a 0.90 microns reflected sunlight and you can see the faint
cloud bands. You can also see the shadows of the ring on the planet up
in the north running through diagonally. But the cloud band runs
horizontally in this image and they're fairly hazy.

But if we look at 5 microns which is the right image, you see all the
structure. And what you're seeing here is holes in the clouds that let
infrared radiation from deeper, warmer levels escape to space. But it's
obviously - we're seeing clouds that are deeper than the clouds we see
in invisible light.

And this has gotten us all excited because of - one of the mysteries or
one of the unknowns about - the meteorology setting is what's going on
in the deeper fluid underneath what we see. And so now it appears that
if we look at 5 microns with the (dim) - we can see these deep clouds
and may measure the wind.

Moving right along here to the next slide, God, my computer is not
working too well. It shows the same thing and we - there's a lot more
structure in this deep cloud that we can see. That little red box up in
the left has been expanded in the - down in the right and there's a lot
of structure. And we can't see structure like that in the visible. It's
much more muted.

All right. We're moving to Slide 55. You see a sort of a montage of
different images that were taken in visible light by the imaging. The
one in the center at the bottom is especially interesting because it was
taken not using sunlight to illuminate the planet but it was taken on a
night side of the planet when there isn't any sunlight but they're light
reflected off the ring. So we're basically using ring shine the way you
might use moon shine to make photographs at night.

Except that the rings are so big and they cover the scene so thoroughly
that a ring shine is actually brighter than the full moon at Earth. You
can definitely read the paper by ring shine at Saturn. And so that
strange storm that almost - it looks like a face tilted over is a storm
that we saw in ring shine.

Now actually, we were told to look for that storm by another instrument
on the spacecraft, the RPWS, the radio wave instrument and they were
seeing - to them, it looked like the radio signals from lightning
flashes.

And they said we're getting lightning; we're detecting lightning in the
radio. We want you guys to look for the storm that's producing it. And
we said, well, we can't because the spacecraft is looking on at the
night side right now.

And then they said, we'll, (tough), we'll ask the amateur astronomers to
see if they can see the storm. The amateur astronomers found the storm
first and then we went and look at our night side images and found, yes,
we could see it too by ring shine.

The next slide which is 56, shows some of the \-- so where is 56? \--
shows a time sequence of the storm. We called it the Dragon Storm in
2004. We've been watching a similar storm in 2006. And it's very active
and when it's most active as measured by the brightness and the motion,
that's when the radio signals are at the greatest.

Now Slide 57 shows you a time history in 2004 of the radio signal. Each
spike is radio signal and they're spaced 10 hours and some minutes apart
because that's the rotation of Saturn. And every time a storm is on the
spacecraft facing side, you get these radio signals and then Saturn
rotates and then the radio signals die away.

And indeed it all matches up and it appears that we've got a very
powerful thunderstorm or (unintelligible) thunderstorm on Saturn. The
radio signals from the storm are brighter, more powerful than anything
on Earth. We don't quite understand why the lightning storm should mean
so much greater on Saturn than on Earth or Jupiter.

Okay. Moving on to Slide 58, shows picture of the aurora in Saturn
northern - and particularly southern hemisphere. These pictures were
taken one hour apart. And if you look carefully in the southern
hemisphere, you can see changes in the structure of the Aurora which
probably represent the response of the aurora to changes in the solar
wind.

What's going on with the aurora is that charged - electrically charged
particles are flowing in following the magnetic field of Saturn and
they're flowing in a - and accelerated by the electric fields actually
but they're guided by the magnetic field. And they crash into the places
where the magnetic field guides them onto the atmosphere and that
produces a glow in the ultraviolet which is what you're seeing here.

This is taken by ultraviolet spectrometer and I think Don Mitchell will
have some more to say about that.

Next slide, Slide 59, shows further studies of some of these mapping
where the spacecraft was and in connection with where the aurora was
seen.

Slide 60 is just a picture of the wind as we have been interpreting them
but that all depends - and you'll notice that the equatorial wind is 450
meters per second which is about 1,000 miles an hour and it's 10 times
stronger than the jet streams on Earth.

So this is mighty, big wind and Don Mitchell who comes next is going to
tells us that maybe the reference frame that we've been using for the
inside of the planet from which we measure the cloud motion has been
wrong or changing or - (I'm going on) and so may be these winds have to
be, if anything, increased.

But I'll leave that to Don.

We can measure the cloud motions and he's got to tell us what the
reference were - the proper reference frame to use in determining of the
wind.

Don Mitchell is a co-investigator for the magnetosphere imaging
instrument.

Don.

Don Mitchell: Yes.

Hello?

I'm in the first slide that I've got. It's - again, a Word slide. I'm
going to skip over that and you can look at it at your leisure later if
you have questions about the general form of framework that I'm working
in.

But the next slide is Slide 62. It shows a cartoon of the magnetosphere.
First thing you can see is the huge volume. I mean it's (unintelligible)
The day side, the extent of the magnetosphere is at around 30 to 40
Saturnian radii, sometimes being pushed in as close as 20 around Titan's
orbit by the solar wind pressure which is variable.

The magnetic field of Saturn controls the space, separates it from the
solar wind. Heightened orbit is fairly near the magneto (clause) which
is the boundary between the solar wind and the magnetosphere of the day
side.

And Titan goes around and sometimes actually goes out in to the shot
solar wind although we haven't - not encountered Titan in that region
yet. We've been inside the magnetosphere for every Titan encounter we've
seen so far.

The magnetosphere of Saturn is superficially like other magnetospheres
like Earth, like Jupiter but they are of course different from one
another. And what really sets the magnetosphere of Saturn apart from the
others is the amount of dust in, specially cold gas that's
(unintelligible) with the energetic particles in the magnetosphere.

So the red in the outer part of this is part plasma, part, you know,
tens of kilovolts slimmed down to a few kilovolts of energy of hydrogen
and oxygen primarily. And as you get into the inner magnetic sphere,
there's sort of an inner boundary inside of which most of these tens of
kilovolts particles that are gone and you only have very low energy
particles and very high energy particles.

The reason they're gone is because the gas tends to be (unintelligible)
so high if they absorb the charge exchange with ions and the ions are
lost in the system.

And Enceladus of course is a main contributor to that gas cloud (fills).
The existence of Enceladus and its unique geology really are a large,
major modifier to the kind of magnetosphere we see at Saturn.

On the next slide, which is Slide 63, this shows a cartoon of some of
the work that was done on mapping some of the energetic particle
observations in the magnetosphere the aurora observation.

These are Hubble Space Telescope aurora observations that were not taken
simultaneously with the particle data. But we have a certain number of
aurora images from Hubble. And from that we have at least some measure
of the variability of the aurora, Saturn and where its sort of standard
pattern is.

And so what we did was looked at where we were measuring beams of
electrons in the magnetosphere with Cassini and then using magnetic
field models to develop - and partly using Voyager data and in part
we're using Cassini data we mapped where those particles would have come
from if they come from the atmosphere from - and they map back fairly
closely to (unintelligible) region which indicates that we have not only
or - it may indicate (unintelligible) some of dispute on this, but
anyway, to get electron beams out in the magnetosphere, one mechanism to
do that is to have electric fields which accelerates the electrons
upward out of the ionosphere of Saturn.

Those would be in close proximity to electric fields which are
accelerating electrons down into the atmosphere and creating the aurora
in this place. This happens at (unintelligible) you get dark regions and
bright regions in the aurora which are alternate (unintelligible)
downward electric field accelerating electrons either upward or
downward. So this is the first observation of beams like this at Saturn.

In the next slide, the radio wave emission as Andy I think referred to
have been used to - as a proxy for rotation period in the rotation
frequency of Saturn. And as - the assumption back in the Voyager days
was that since the southern kilometric radiation which is a mission
that's caused by some of Auroral Physics at Saturn was very strongly
modulated at a particular frequency which is obviously very close to
Saturn's rotation period.

It was then adopted as Saturn's rotation period on the assumption that
there was some asymmetry in the (unintelligible) magnetic field that was
rotating with the interior of the planet as then expressed out in space
of these radio emissions that were periodic. And so this was soon to be
the period of the interior and therefore our reference frame against
which to measure the velocities of the wind that Andy referred to.

Well actually even before Cassini arrived that we knew there was a
problem with it because the period was drifting and that was seen on the
Ulysses spacecraft which is also able to measure these emissions from
Saturn.

And then Cassini has since confirmed the Ulysses observations and send
them down more tightly and that the periods which seems to be moving
even during the Cassini mission is changed by - a little bit. And total
change from Voyager till now is up to 1% of the rotation period.

Well, that's way too much - much too larger change for it to be the
entire body of Saturn changing its period by 1% because its conservation
of angular momentum just won\'t let you do that to - there are no forces
around that's going to change Saturn's rotation period by that much. So
now we've got a quandary as to exactly what is rotating at this period
and what the proper reference frame for those winds may be.

I'm saying now at this point, we don't have any measure that tells
uniquely what the interior rotation period is. And therefore, the winds
are a bit of a free function. You have to pick a period maybe in - you
may have to work backwards and decide, well, what's a reasonable wind
pattern for the physics that we understand generates wind and then pick
up rotation period over that. Not very satisfactory but with this period
drifting around, it's going to be hard to use as reference frame.

Then the next slide, 65, just shows a confirmation of that period from -
directly measurements of the magnetic field by Cassini. This is the
first time we've got a well-defined a frequency of disturbance in the
magnetic field itself. And this was published in Nature by
(unintelligible) recently.

And the frequency that they come up with is sort of right in the middle
of what the radio frequency was during the same (unintelligible). So,
although it's a different period than what was published for the radio
observation, that's just because the radio people hadn't published from
this particular period. And you say, look at this particular period, it
matches very closely what the magnetic fields on (unintelligible)
showed.

The next slide is a one (unintelligible) that relate the jetting from
Enceladus of these particles and gases into the surrounding
magnetosphere and its effects on the magnetosphere.

In particular, there's this gas flow which we described earlier as
being - as Andy showed in the vicinity of Enceladus orbit peeking in
that vicinity that spreads out to roughly out to 8 to 10 Saturnian radii
outward and (cuts) off at round 3 Saturnian radii in the inside.

And in that same region of space, the upper right hand panel indicates
the composition of the charged particles in the inner magnetosphere and
shows that the water products \-- OH, H2O and H3O and oxygen \-- when
taken together constitute a fire fraction of the ions there than
hydrogen does whereas in the outer magnetosphere, like Earth, hydrogen
is the dominant species. These water products dominate the inner
magnetosphere in the vicinity of the gaps (unintelligible). They - no
doubt are derived from ionization of these gas clouds.

Then the next slide shows a superposition of the gas cloud on energetic
particle data that was taken during the Saturn orbit injection for it.
And these energies are running up to - it's in the scale of (large
rhythmic) and they go up to about 220 kilovolts and down to - at the
lower end at about 3 kilovolts. This is hydrogen and the oxygen was very
similar in morphology.

And right between (6RS) and (6RS) which is - I've indicated on the
bottoms axis, we get down through about one (Saturn radio). But there's
simply aren't any particles in this energy range inside of about (6RS)
because of the gas probably which - while it's producing the plasma in
the magnetosphere is also absorbing the energetic particles in that part
of the magnetosphere very effectively and keeping the inside - inner
magnetosphere much lower in energetic particle flux that it typically
would be if these gas clouds were not there.

The next slide is pictorial which just shows the charge exchange
interaction which is important to what follows. All the planets -
there's an interaction between (unintelligible) in the same state. And
an ion that is spiraling about a magnetic field because of the
(unintelligible) force on it, in charge exchange pick up an electron
from an ambient full gas particle.

And when it does so, it will become a neutral particle but it will
retain its energy. There's very low energy transfer because the mass of
the electron is so low so that the charged particle becomes a fast
neutral which then escapes from the system because it no longer feels
the magnetic force.

So, you can think of the entire magnetosphere region emitting the fast
neutral atoms. And the ray of emission is going to depend upon on a
number - the intensity of the charged particles and the gas density.
It's that combination that gives you this product.

The next slide is just an indication of a gas cloud with - this is now
hydrogen gas cloud, not the oxygen gas cloud I was talking about before.
And for reference, I've got the blue oval is Titan's orbit. So that's
how there's 20 Saturnian radii and these hydrogen clouds are much more
extensive and goes out for 45 to 50 Saturn radii even beyond that.

And (unintelligible) in a particular geometry here where the magnetotail
would be, the sun would be to the lower right in this image. So it's
sort of (winds back) the magnetotail up into the left as it - during the
summer we're in.

And I placed Cassini in the image because the following slide will show
images of the emission of the fast neutral atoms from the magnetosphere
and its interactions between the ions and the gas.

So this next slide shows a representative image like that. It shows the
Sun to the lower right and the tail region back where the magnetotail -
that magnetotail is the brighter region. And we've seen this is a
repeatable signature in this emission. So there seems to be a reservoir
of more energetic particles back in the magnetotail region.

We really haven't explored that region yet. But with these images -
these remote images of the system, we've been able to see that they're
back there and anticipate measuring them (unintelligible) when we get
there.

The next slide shows emissions in that region were very much more
concentrated and brighter in both hydrogen and oxygen which was
published in Geophysical Research Letters back in June of '05. And that
was a bit of a surprise to see the oxygen (unintelligible) it was back
there since oxygen is a much smaller constituent of the general charged
particle population back there. But it seems to be much more
efficiently - it's much more efficiently accelerated.

And then the next slide shows a composite of images in the lower left
from that same time period which again the magnetosphere stretching away
to upper left and some sort of the lower right in each of these images.

And in this time sequence you can see the magnetosphere going from a
rather quiet state to a very great brightening back in the tail region.
And then that generation of charged particle is picked up in Saturn's
rotational motion and thrown around Saturn as the charged particle
travel over Titan which is in the path - in their path as they're
co-rotating around Saturn, they envelope Titan and you get a very
dramatic brightening of the emission as the cloud moves over Titan which
is in this sort of a center image of this sequence.

And that's because Titan is carrying along with that its own neutral
atmosphere which is a very dense gas that surround it and produces a
large emission of this energetic neutral atoms as they come off it.

In the upper right is an example of a Titan image that when we're
approaching Titan in close encounter with Titan and you can see this
emission from the upper atmosphere as that dense neutral gas charged
exchanges the energetic ions in the vicinity of Titan and provide sort
of this bright emission around Titan.

And then the last of the slides that I have - a framework for a movie
that you could have downloaded and (watch). It's just a reference slide
for that movie. It's the first frame of it. But the movie includes the
data from a previous slide and much more allows you to go through to the
time sequence and watch the development of that as it goes along.

So with that, I'll turn this talk over to (Jeff). I guess that if there
are any questions that would people like to ask now, they can. But
otherwise (Jeff Cussy) will continue with the rings..

(Jeff Cussy): Okay. I'm here. Thank you, Don.

Okay. So the first slide is a bunch of bullets and things that I'm sure
you all know so I won't - I really won't dwell on it. And I'm just going
right to the next slide.

And this will remind you a bit of what the rings look like just from the
nomenclature standpoint. The innermost ring there, designated the C ring
-I'm not sure - let me just go back to - okay. This would be Slide
Number 75 and it's numbered.

This is actually a semi-correct color composite of the rings. You see
the brightest ring there is called the B Ring. It's full of structure
that we don't understand. The outermost ring is the A Ring. And just
outside the A Ring we have the sort of narrow strand, the thing called
the F Ring.

The Cassini's vision between the A Ring and B Ring and the C Ring which
is the innermost ring are very similar in a lot of their properties, and
I'll have more to say about that later. And just to remind you that the
structure in here - almost none of the structure is understood.

A little gap in the outer part of the A Ring is the location of an
embedded moonlit (copan). And a very almost invisible threadlike dark
line at very outer edge of the A Ring is another little gap where we
have discovered another moonlit which I talked about last year.

Okay. So that's what the rings look like on the lit side. This is what
they look like on the unlit side on the next slide. And what you see
here is the darkest thing which is the B Ring. It's dark because very
little light actually gets through.

And the Cassini division which is in the middle of the frame and C Ring
over tot the right are actually bright you're actually seeing
illuminated particles from the - on the illuminated side. This is sort
of just an orientation picture and you see the little red box in there,
it shows you the field of sort of the next image which is - now you can
click the next image.

And here what you see is actually our first discovery of spokes from
Cassini. This happened last fall right around last - oh I guess it was
in September. And we have been not seeing spokes. Spokes are sort of
shadowy finger-like structures on the rings that the rings are just
covered with theses things as seen by Voyager. They've been seen from
Hubble.

But then as the rings (unintelligible) it tended to get more and more
open to years from the sun, the Hubble sort of stopped seeing them. They
gradually vanished and faded from sight. It's a bit of a mystery as to
why that is. It's thought that it has to do with silver illumination of
the rings and charging of the rings actually some light (unintelligible)
electrons above the rings that creates a charge, a negative charge
around them and electric field between them and the material around
them.

So any little dust screens get (popped off) into this charged
environment get immediately sucked right back down into the rings and we
tend not to see spokes. So by that theory we should expect to start
seeing spokes again when the elevation angle to the rings
(unintelligible) down again probably in a year or two.

But this will happen right before Cassini went into equatorial orbits as
seen in the next slide. And basically this is what we've been looking at
for the next nine months - for the last nine months. With the orbiter,
this is terrific geometry for the atmospheric people to (stay at) the
cloud bands as Andy described to you. It's rather boring from the same
point of ring people. So we have been making - used to the time actually
going back and analyzing data and having a lot of fun turning up
discoveries and data that got taken months and months and months ago
that we just had - really had a chance to look at.

But as of this summer, late July, Cassini will again re-emerge from the
equator plane for about a year of highly inclined orbit and will be back
in business.

Okay, next slide.

I want to just remind you, showed you the main rings here. There we also
have these already diffused rings. There's the - on the top panel,
there's this very diffused band that the E Ring - which is sort of
centered on the satellite Enceladus that you've heard all about.

And then just inward to that, between that and the main ring is the
center ring called the G Ring. Well, this is - the three panels found at
the bottom show the G Ring. It kind of actually show what Cassini
discover as an art in the G Ring that is it's not a symmetric structure.
It's got this sort of anomalously bright region in the less ten frame
sort of indicated where the arrow is, so it's sort of rotating around
counterclockwise from lower right, at the left picture to sort of right
at the onset or the rightmost curve of the ring in the center picture.
Then it's moved around a little bit to the far arm in the right hand
picture.

This arc, it turns out, is right at the very inner edge of the G Ring.
And we're starting to try to get some periods on it right now and try to
figure out if it's tied to some satellite or other. But it's definitely
a new discovery from Cassini.

Enceladus, I'm not going to say much about because everybody else has
talked it. But we do know now Enceladus definitely is the source of the
E Ring.

Next slide shows some measurements of the E Ring from inside the E Ring
by the CDA, the Cassini Dust Analyzer or actually, you know, we're
orbiting in the E Ring for quite a bit of time especially this one
orbit. This data is taken from Orbit No. 15 which is an equatorial orbit
for actually just in the E Ring the whole time and just coming out
briefly so the CDA can get beautiful data on the radial structure of the
E Ring in terms in the number of particles per unit volume.

The vertical structure on the upper left here which actually shows if
you look at the points, there's actually a hint of a double peak profile
there which is similar to what we see Jupiter - in very faint rings of
Jupiter, that is. Because like any harmonic oscillator, like a ball on a
spring going up and down, you know, or a child on a swing, you know, the
child on the swing let's say spends more time at the extreme points on
its swing back and forth than in the middle.

So these particles actually tend to spend more time either at plus or
minus vertical distances from the exact midpoint. And that seems to be a
little bit of hint of what we're seeing there along with a sort of a
sudden offset which has to be understood.

The bottom right hand panel actually indicates that the orbits of these
particles are nearly circular. But this particular data if you see the
legends on it, are actually taken out around 8RS. So if you look up at
the top (ply), you see 8RS, eight southern radii. It's all the way over
the right hand side of the plot. It's not really in what you might call
the Enceladus part of the E Ring where we expect the particles are very
eccentric because of a combination of sunlight and radiation forces.

So this is very interesting that theses particles are circular but
what's really going to be interesting is way around the mission when CDA
is able to make these orbital (dynamic) measurements in the E Ring
proper.

Okay, moving on to the next one.

This is a server composite here of various things. The top panel shows
something they feel sort of right at the beginning and the bottom right
hand panel show sort of a close up to the same structure. These are the
strands of the F Ring which I - as I showed you is just sort of outside
of the A Ring.

Now these bright strands just a sort of a mosaic are taken in the launch
two direction that breaks back on the top panel all the way over to the
right \-- this is Slide Number 82 \-- is actually Prometheus itself.

And so we're - as we go the left, we're looking downstream from
Enceladus. This is stuff that's further and further away in the orbital
direction from Enceladus. Enceladus is actually moving faster to the
right than the ring material is.

Man: Don't you mean Prometheus?

(Jeff Cussy): Prometheus is one of the two small ring moons just outside
of Saturn's main rings.

Man: You kept saying Enceladus.

(Jeff Cussy): No.

Man: Okay. Prometheus.

(Jeff Cussy): It's Prometheus now.

It used to be thought that - there's actually another little moon called
Pandora just on the outside of the F Ring. You can't see it in this
picture. So there's one in the inside and one in the outside. It used to
be thought these things were actually confining the F Ring. They were
called the F Ring shepherds because of the idea like shepherds confine
in a flock of sheep. But now we know that's probably not the case. The F
Ring is in a region where a lot of orbital chaos is going on and I'll
say more about that later.

But when you see these beautiful fan-like patterns here and that was
really kind of a puzzle. We called these channels. They actually look
like these places where materials are piling up and other places where
materials are being removed.

It was kind of a puzzle as to what was going on there. In the bottom -
in that right hand lower picture where you can see Prometheus itself and
you can see its little bright crest and even in its dark side, you can
actually tell that it's actually pulling a little piece of material away
from the F Ring.

So one thing people have actually done and I encourage you to look at
this movie perhaps offline; it's called the F Ring movie and I don't
think I can actually show it from within the PowerPoint here but go
ahead and take a look at it. And what it shows is this panel on the left
shows us - it shows a (unintelligible) particles in the F Ring strand
shown schematically. And Prometheus just inside it.

And what you'll see in the movie is Prometheus moving in and out because
its order is eccentric and the entire F Ring also moving in and out
because its order is eccentric as well. And you'll see the ring material
flowing past Prometheus and what you see is Prometheus curving out these
channels. But as time goes on, the appearance of the channels actually
changes with time.

And you see, you know, sometimes they're open like we see them here in
this picture, in the snapshot, and sometimes they close up and look more
like pinwheels.

So the whole nature of all the system is very dynamic and it changes
depending on how close Prometheus is to the F Ring as a function of
time. So this is starting to become a little bit more well understood.

Next slide shows some stuff that we still don't understand very well.
The bottom, very messy looking panels are the F Ring again stretched out
in longitude. In fact, it's repeated twice; so it's actually the F Ring
and then the F Ring again to accentuate the fact that these blurry
strands are in the nature of a spiral that is a - they're tilted from
the orbital direction and you can follow one around and it wraps in to
the next strand.

So this is actually a spiral and it's believed that this is caused by
some object actually going through the F Ring. And the object that may
be responsible for all of these chaos is this little thing called 2004S6
which is shown in these two panels at the top. Only you notice in one
panel, the little object is all the way outside the F Ring and in the
other panel, it's actually inside the F Ring closer to Saturn.

So this thing actually crosses through the F Ring. Its orbit is very
eccentric. And as it crosses through the F Ring, we think it probably
hit something or dynamically perturbed the F Ring).

So if you look at the bottom panel on this messy thing down here and
step to the next slide, you'll see a big black X show up and that is the
longitude where it's been predicted that this little object, S6,
actually went through the F Ring. So this is a very, very dynamic
structure changing all the time.

Okay. So I want to move on to the next subject here which is - this -
the label on this is in white so you can't see it but it's a - not a
particularly impressive-looking slide. But the scientific content is
very, very important.

What this represents is discovery of little things buried inside the
main rings. Now this is - and so we notice there are moonlits called
(unintelligible) clear out these little gaps in the rings, gap - the
(unintelligible) gap s cleared by a moon that's about 10 kilometers
across which we can see.

But here, this is stuff that's buried in the main rings. These little
double dash structures that you see here \-- these all horizontal dashes
that are slightly off set in each one of these panels \-- are slightly
cleared regions that are caused when there's a little object right in
the middle between those two dashes maybe several hundred meters across,
okay, a couple of times the size of a football field, way to small to
see, even in these images which were taken at orbit insertion and they
are the highest resolution images we will ever get, they're 50 meters
per pixel.

What were seeing is little cleared regions just around some of these -
well, what do you call them? We don't really have a name for them yet.
We're calling them "propeller objects" for sure because they cause a
structure. But there were four of them - four different ones seen and
you can do the statistics.

Next slide kind of shows where these things fall. This is a size
distribution plot where the solid line at the upper left kind of shows
your normal tight ring particles from centimeters to meters. And then
down at the bottom right, you have the diamond which shows the two
moonlits that we know are there. And you might imagine a line running
between the largest ring particle at about 10 meters and the moonlits
that we see. And you see these shards, these propeller objects that
we're seeing in the A Ring, these two symbols of the (unintelligible)
are not too far off that line.

So, the implication is there's a whole population of objects lying right
in the main ring from sizes between tens of meters, hundreds of meters,
kilometers, you now, extending all the way up to the biggest things that
we can actually see which are big enough to cause gaps.

So it's - a lot of these other things are not big enough to cause gaps
but it's very, very interesting that they're there.

Okay.

So I want to move on, in the interest of time to - oops, I skipped one.
Okay. Now this is an image that shows - now these are the collection of
the stellar occultations we've had and where a star is seen to go behind
the rings by Cassini and the (unintelligible) takes very rapid sampling
measurements to measure the brightness of the starlight which samples
effectively the amount of material in the ring on a very, very small
spatial scale, tens of meters.

What you'll kind of see in here - sort of at the lower left and at the
lower right, there are radial profiles of the amount of material in the
A Ring, showing the outer edge of the A Ring very abrupt
(unintelligible) gap is and then it's kind of flat. And then you go to
the inner part of the A Ring, the optical depth so the abundance of
material rises again and then it drops abruptly going down into the
Cassini division.

The colored bar at the bottom also indicates optical depth. But you
notice that depending on where you are around this clock - this -
(unintelligible) is variable, the optical depth in the middle part of
the A Ring actually changes. It's much higher over on the right hand
side than it is over on the lower side which is very interesting because
it's saying that, you know, well, that you just - it's like looking
through a comb at different angles. That's the interpretation.

So let's just go on the next slide now. I'll jump to the bottom line and
show you the interpretation here.

We believe that in the middle, in fact we know now Cassini has
demonstrated it, that in the middle of the A Ring, the mass density of
the particles is sufficiently high that the whole system wants to become
gravitationally unstable and clump up and form bigger particles; maybe
like how planets first formed in the solar system.

But because this particles are too close to Saturn and they're moving
with respect to each other, like the ones that are closer to Saturn are
moving faster than the ones that are further away, these clumps get
stretched out into this finger-like structures. This has been modeled
for many years. But this is really the first instance now that we can
actually observe it.

Now, the next slide shows you that as you can imagine looking through
this finger-like structures at different - as (unintelligible) angles
and in (unintelligible) angles you'll see the star better than in
others. And this depends on the size, the (widths) and the vertical
thickness of these fingers. Okay? So you'll see these - some angles here
where these things corrupt the star very nicely.

Okay. Next slide actually shows how - what we can learn now from all
these occultations.

We can learn basically the green shows the optical depth. If you like -
if you make a simple model now, you have these fingers and you have an
amount of material in the finger which would be sort of the blue or the
average. And then the green would show you the amount of material in the
spaces between the fingers. And the red points show you something that
we can learn which is sort of the height of these fingers compared to
their width.

And so from all of these various occultations of the ring we can
actually see now how these things vary throughout the ring. We're
getting very three-dimensional picture here. Like for instance, this is
the A Ring going from 122,000 to 137,000 kilometers. You can see the
gap - where the (Yankee gap) at about a 133,000.

So this height, the thickness of these tubes increases gradually and
systematically as you go out in the rings to a maximum (unintelligible)
in the outer A Ring, possibly because of a lot of density weights there
to stir up the material.

Very interesting stuff, lots to see here. I'm going to have to move on
because of the time though.

So but just to summarize that in a word, we are now certain to get
really three-dimensional information on the rings on this micro, micro
scale of only tens of meters.

Okay. This slide actually - just a reminder, this is the shadow of the
rings on the planet. Remember the B Ring is very dense. It has very,
very dark bands right through the middle of the B Ring where no light
gets through.

Next slide shows you we're starting to peek through that dense material
with the radio occultations to see really how dense they are in the
middle. And what this shows is four panels where the radio occultation
team has averaged their signal to different degrees just to see how deep
you can get. And as they average it spatially more, the blue line which
represents - the blue dash line which represents the noise level, moves
down.

And you can see that there are regions in the densest part of the B Ring
at the bottom line hand panel where the amount of material here has a -
what we call an optical depth greater that about 6 which means, you
know, less than E-3 or you know, I don't know, much less than a percent
of the material gets through. And there is still that one very dense
part right around the 106,000 kilometers where we're just not seeing
anything. So that is a very interesting region to know what's going on
in there.

Okay. This next slide, Number 93, just - is a reminder that we're still
taking temperatures of the rings with (unintelligible) and we're still
measuring the composition of the rings with VIMS. And you can't really
read the bottom so I'm going to just go on to the next slide and show
you an example of what VIMS can do.

This is actually my last slide or pair of slides.

These are spectra of the rings that is the brightness is function of
wavelengths mostly to the near infrared and is taken by the VIMS. And
each different color line is a different region of the ring; so the
higher brightness is to the top that goes 1 micron, 2 microns, 3
microns.

The first thing you see is that these spectra have this big, deep bands;
these deep absorptions that were about 1.6, 2 microns and 3 microns.
This is due to water. We've always known the rings are mostly water;
this is not a surprise. But the different depths of these bands is
really starting to tell us a lot of interesting stuff.

Notice at about 1.2 microns, 1.3 microns in the less 10 panel, there's
a - sort of a very weak band all the way to the left at about - just
about - just longer words or 1 micron and then there's another one at
about 1.3 microns. And notice as you go down the plot, the depths of
that band pretty much goes away. And it's quiet deep in the purple line
which is the outer A Ring but then by the time to go around the red line
at the bottom which is the Cassini's vision, there is no water or ice
band. This is very weak band. It's easily obscured by their pollutants
like dirt or silicates or carbon or something.

So what we're really seeing here is starting to see how the composition
of the rings varies from one region of the ring to the next. And you can
see that even comparing the left hand panel to the right hand panel.

Now, the next slide indicates - this actually shows you where all the
water ice bands are. And it also shows where there's a silicate
structure. In the right hand panel you sort of see this curved
rainbow-looking line here, this boomerang-shaped thing.

The shape - that spectra shape is diagnostic of silicates and we're
seeing it in the C Ring and even maybe - and certainly in the C Ring.
You notice the shape of that spectrum is very different from the shape
of the spectrum - the same spectrum region in the A Ring over on the
left hand panel. So things really do vary from place to place in the
ring so we're just starting to get a handle on that now.

The question mark features down there might imply some kind of organic
material. It's a little bit early to say right now.

Okay. Just to summarize, we have been focusing on data analysis. We're
really understanding, I think, these curious channel structures in the F
Ring and how they change with time.

We've discovered the strands and how these marauding moonlit, you know,
that was barely visible in the Discovery image by Cassini, published in
the (unintelligible) is barely visible, now it knocks your eye out. So
that thing is probably changing the time and it's going to the F Ring
and it's causing a lot of chaos.

We found new kinds of objects - transitional size objects in the main
ring and also in the F Ring.

The 3D holographic structure of the rings, we're starting to map these
out now with all this occultations and we're learning a lot about these
gravitational instabilities.

Finally, we're starting to get compositions. We've seen structures -
features, special features in the rings like on some of these other
moons that VIMS is observing including Phoebe which is thought to be
sort of a captured comet.

We found spokes and we're looking forward to seeing the rings again
starting in July.

So that's all I have to say.

Man: Okay. Great. Thanks, (Jeff), and everyone.

The rest of the presentation, there's a few more charts about what to
expect for year three. I'll go over those since you may have questions
you're more interested in asking the scientists.

There's also some charts that again Andy had to follow on some of his
discussions.

I show about five minutes left. So, you know, if anyone (unintelligible)
otherwise we'll open for any questions you have for the scientists.

Man: (Unintelligible)

Man: I have a question and comment.

Woman: Can you please say you name, please?

(Matthew Otto): It's (Matthew Otto) with the Observation Campaign.

Man: Go ahead.

(Matthew Otto): Yeah, this is for (Jeff), just to comment about the ring
spokes. Voyager in my understanding did not discover the ring spokes.
They're actually observed prior to these spacecraft flights by amateur
astronomer named (James) - Stephen James O'Meara who actually is very
famous for having a sharp eye. He was observing these spoke-like objects
from Earth with a telescope it was confirmed by the Voyager as an image.

(Jeff Cussy): That is - you hear that. I'm very skeptical of that
frankly. There have been lots of claims of people seeing spoke-like
structures in rings going back in fact into the last century by various
people; it's all in Alexander's book.

But I don't know. The Hubble is by far, you know, the most sensitive
thing and I think the geometry if I understand correctly of when O'Meara
was actually observing the Hubble just as has never seen anything there.
So I don't know. It's conceivable but very hard to prove as you know...

(Matthew Otto): Right.

(Jeff Cussy): ...with eyeball observation.

(Matthew Otto): Well, I beg to differ since the Hubble is, you know,
isn't really comparable to the human eye in many respects. But yeah, we
agree to disagree on that.

Thank you.

(Ken Kramer): Hi. This is (Ken Kramer). I have a question about Titan.

There was a lake you may have identified near the south pole and I'm
wondering what's the latest thinking on that.

Woman: It's a - there haven't been any further observations of that
area. The south pole is of course the region where we had seen a lot of
clouds although there haven't been many clouds observed at Titan in the
last year. But the fact that we'd seen clouds that look like convective
clouds will be consistent with precipitation in that region.

The hope is that we'll get a better look at that on the 38th Titan flyby
with the VIMS and ISS instruments but that's still up in the air,
actually. And the radar we'll see some areas near the south pole on the
39th Titan flyby which could help identify whether or not there are
liquids on the surface there.

Unfortunately, in terms of looking for a specular reflections or
something like that off the surface, something that's close to the south
pole, we won't be able to do that with the - certainly with the camera
and I'm not even sure that VIMS would get an opportunity to do it.

So there is no update specifically on that feature at this point.

(Ken Kramer): Okay. Thank you.

Woman: But hopefully, in the future we'll get a better look at it.

(Ken Kramer): I have another question too about Enceladus. When will we
visit that again and what more do we hope to learn?

Don Mitchell: Well, there are a number of sort of distant flybys and
we're going to be looking at the plumes from various angles and in
various colors and try and get a better handle on the particle size.

And then we have an - I think March of 2008, a close flyby of Enceladus
in which we can do it all over again. And knowing what to look for, we
ought to do a better job, get really high resolution imaging and insight
to sampling with the INMS instrument. So it's just going to be spread
out but the March 2008 is the big one.

(Ken Kramer): Great.

(Cyril Prall): This is (Cyril Prall), of Rochester, New York. I have a
question for anybody.

Can you hear me?

Don Mitchell: Yup.

Man: Sure.

(Cyril Prall): With all the charged particles and other so called
radiation in the general vicinity of planet Saturn now, if at some point
in the distant future, human beings were to go to visit that region, how
dangerous would it be from a radiation harmful effect to the human body
point of view? Does anybody know?

Don Mitchell: This is Don Mitchell.

It's pretty benign compared with Jupiter and even compared with Earth
because of the - what Enceladus does to the third particle population,
they're pretty weak Saturn. There are (unintelligible) electrons that
are high energy and some very high energy ions to the region between the
orbit of Enceladus and the outer edge of the rings, it's kind of a
dangerous place to go radiation-wise.

But any place that maps inside the ring would be extremely benign and
even the magnetosphere outside of Enceladus is fairly benign.

(Cyril Prall): Thanks.

Man: Thank you.

Man: Any further questions?

Okay.

We can end this then.

Man: Okay. Thanks to you all for dialing in and listening. Hope to see
you next time.

Man: Thank you.

Man: Goodbye.

Man: Excellent telecom. Thank you.

Woman: Take care.

Woman: Hello?

Hello?

END