**RAW transcript - not yet corrected by mission technical staff.**

**FTS-NASA-VOICE**

**Moderator: Trina Ray**

**August 29, 2006**

**1:00 pm CT**

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Thank you.

Ma'am, you may begin.

Trina Ray: Thank you. And welcome everyone to the CHARM telecon for
August.

We have a terrific talk today. Dr. Larry Soderblom is joining us. He's
an interdisciplinary scientist with the Cassini mission and works for
the United States Geological Survey and has done quite a bit of work in
his career on the large moon of Saturn, Titan, and today he'll be
telling us about that.

Just a reminder to the participants, star-6 is what you can press to
mute and unmute your phone regardless of the capability of your phone.
So, that's a handy feature.

And with that I will turn it over to Dr. Soderblom.

Larry Soderblom: Okay. Thank you Trina.

This is a lecture that I gave on the 31st of July just a month ago. It's
a lab-wide talk at JPL on the subject. And Trina asked me to give the
same talk today. So, if you were in attendance to that talk, you might
want to find something else to do.

I have included all of the slides from that talk even though many of you
are experts on Cassini having heard many talks through this telecons.
But you're welcome to cannibalize this talk for your own use since I
included all of the slides for that reason.

Also there are number of movies that are on the Web site that I've
concluded that are not actually in the talk but they were on my laptop.
You're welcome to use those in any fashion you like. They're all there.

So with that, let's - there are 54 time steps in this and I\'ll try to
keep remarking as to which time steps are on so you can follow along.

There are also two very large movies that Trina mentioned produced by
Erich Karkoschka at the - from the DISR team at University of Arizona
which are included and embedded in the talk.

I won\'t actually go through those movies. They're nine minutes each.
And they have very fine soundtracks over them. And you're welcome to use
those and perhaps view them after the talk. But in the interest of
saving time, let's do that offline.

All right. So, the subject of the talk Titan and Earth-like alien, I
think the most remarkable thing that we keep finding out is that even
though Titan is such an alien environment in terms of its chemistry and
temperature, the more and more we look at the geology of Titan, the more
it starts to look like a glossary out of the textbook of geological
geomorphology of the Earth. And so - which is very striking for those of
us that expected such a bizarre and alien landscape.

So let's go to the second slide.

These are the - this is the obligatory cultural slide. The two
individuals for which the Huygens Probe and the Cassini Spacecraft were
named.

Our next slide shows the Cassini Spacecraft on the left with the Huygens
Probe attached to it and the Huygens probe being assembled on the right.
Again, these are general slides for your use.

The next slide reminds us that we arrived in mid-July or 1st of July in
2004 - mid 2004 and spent several orbits preparing for the release of
the Probe on Christmas Day 2004 and then encountered impact with upper
atmosphere of Titan by the Huygens Probe occurred on January 14, 2005.
So, about a year and a half ago.

Next slide.

So, I\'m reminding you that Titan is a large object. It's larger than
Mercury. It has a nitrogen atmosphere like the Earth. It's not just an
atmosphere, it's actually four times as dense as the Earth owing to the
fact that its surface pressure is 1-1/2 times greater and the
temperature is a factor of several times lower. The surface temperature
is in the order of 95 Kelvin, 96 Kelvin probably a small variation over
the globe.

Also Titan's atmosphere is known to be rich in hydrocarbons. We measured
methane in the atmosphere as the Probe descended that was known to exist
there. It varied from about 2% at high altitude to the order of 5% in
the troposphere. And then as the Probe set on the surface, methane
issued out of the subsurface reaching even higher vapor pressures.

So, methane is a key to what we expected. And as you know, we were
wondering whether the Probe would go splash or split or (tickle). And
so, the splash was - for those that hoped that we might actually land in
a methane lake or sea, as you know, we landed on something more like
faux sand.

And - but the methane and ethane in combination on Titan act like water
dust on the Earth. In other words, there is an ingredient which is
mobile as a gas, a liquid and even as ice particles and clouds and snow
in parts of Titan. But we expected to see perhaps methane rain, perhaps
methane rivers, perhaps methane lakes and seas. We'll get back to those
later.

So, the methane is also known early on to be converted to a whole range
of hydrocarbons due to exposure to ultraviolet photochemistry in the
upper atmosphere converting it to higher order hydrocarbons and
combining it with nitrogen to form nitrogen compounds or nitrile
sometimes including things like cyanogens and cyanide-based materials.

So in addition to methane rain, we expected a whole host of coatings of
black to brown to yellow, orange hydrocarbons snowing down out of the
atmosphere.

Going to the next slide which is \-- let's see \-- the Slide 6, list
some of these - this is a slide I\'ve got from Jonathan Lunine. And it
shows that these compounds that are converted from methane which is CH4
are quite a wide variety. Ethane is the only one that is liquid and is
miscible with methane and might well be found in methane/ethane liquids
on the surface on these lakes - putative lakes and rivers and so forth.

Also, the other materials are solids \-- acetylene, propane, the
cyanide-based compounds \-- and we might expect a small amount of carbon
dioxide on the surface as well.

Going to the next slide, so, the difficulty of course all the way back
to Voyager is seeing through the atmosphere to the surface analysis of
our Voyage images just a few years ago by a number of folks at U of A
showed that there were subtle features that might actually be visible.
But for the most part we have not seen the surface until Earth-based
Hubble Space Telescope images and near-infrared images started to reveal
features on the surface.

So, as a result Cassini carried an imaging radar and near-infrared
spectrometer which is called VIMS, Visual Infrared Mapping Spectrometer;
and of course, the DISR probe which floated down through this (hazy)
atmosphere was able to image the surface.

And I\'ve been privileged to be a team member of all three of those
teams \-- the Radar Team, the VIMS team, and the Huygens DISR team. And
that's the basis of the talk today that I\'ll be talking about in
combination all three of those data sets.

So, in addition to the fact that it has a thick atmosphere and difficult
to see through, it also has the thick atmosphere or (mix) that's ideal
for visiting the surface by spacecraft. It's probably one of the easiest
targets to get a spacecraft to the surface. The surface is cold unlike
Venus which is- although a thick atmosphere, the surface temperature is
about what you'd expect if when you're modern oven is in a safe-clean
mode. And that's tough on electronics.

The Huygens Probe was able to survive more than two hours owing to this
benign environment and it actually - it probably somewhat longer
although the Cassini Spacecraft basically flew out (of) radio contact.

So, in addition to the atmosphere and its interaction with rain and
clouds and rivers there, we expect internal processes as well and
tectonism and what's the basis for that.

We believe that there's a lot of ammonia available in the interior of
Titan. And that will mix with water to form a hydrate lowering the
melting temperature of water-ice from 273 Kelvin to about 171 Kelvin.
And so, this by Titan standards, this is extremely hot material.
Remember the surface temperature is the order of 95 Kelvin.

So when this lava-like material, this ammonia water hydrate erupts under
the surface, it would form a gelatinous gooey mass that would march
across the surface in an almost revolting sort of mode.

And so, that's another thing we expect to see and in fact some of the
DISR images suggest that we might actually be seeing some of this
ammonia water volcanism. And the VIMS Team has also a published a paper
suggesting there might actually be cryovolcano of that material.

On the next slide which is Time Step 9 shows three beautiful images
provided by the VIMS Team, work of Jason Barnes at the University of
Arizona. You'll see the equatorial belt of Titan. It's basically
remarkably similar in appearance to the dark equatorial belt of Mars.

As a matter of fact, if you look and detailed it, a number of the
margins, the sort of serrated jagged edges between the bright and dark
terrain suggested perhaps wind-stripping; and in fact on later images
that I\'ll show you suggest there's a wide variety of alien processes
active in addition to the fluvial processes we see on Titan.

Next slide shows the radar coverage as it was being built up over the
course of the last couple of years. TA which is a high-latitudes - by
the way I should remark that in the equatorial belt, I noted that it was
a dark band around the equator with the exception that it's interrupted
by a very bright region called Xanadu known from the Earth for a long
time at about 90 degrees longitude you can see in this region and will
come back to Xanadu in that.

But TA was our first path and it was a fairly high north latitude. If
you look at Slide 11, you'll see that we - numerous features that the
radar team interpreted to be related to tectonism and volcanism. And
remember in the volcanism, we're talking about here is this
cryovolcanism involving materials that are the order of 80 degrees
hotter than the surface itself.

The image on the center tier on the left is a large pancake dome very
similar to those that we see on Venus, the order of 150 km across. These
show patterns throughout (some) radio patterns and so forth suggesting
of volcanic flow.

The feature in the center reminded me of the grooved terrains on - that
we see in particular on Ganymede, but in the other solar system IT
Satellites these are tectonic patterns produced by a variety of
extensional processes involving injections of volcanic material on a
long fault plane. And - so, volcanism and tectonism was a key.

The slide on the right was dubbed CC, the cat, by Charles Elachi on the
first day we saw this. And it was our first suggestion that we might be
seeing things that were darkened off that there might actually be a
liquid there. On further inspection, these are still quite bright
compared to what we'd expect. And we'll come back to that a bit later.

But so far, what we've been seeing in the equatorial or mid-latitude
regions that convinced us that we're actually seeing liquids on the
surface.

On the next slide, we go back to looking at the radar coverage. And T3
which is - just south of TA was the next path. And Slide 13 shows you
had a different set of processes.

So, we had tectonism and volcanism in the TA path. In the T3 path, we
see on the left-most side, what we interpreted the longitudinal dunes.
This turned out later \-- and I\'ll show some - another slide shortly
\-- to be pervasive throughout the equatorial region and they are dark.

And a key feature to remember here is the dark longitudinal dunes are
the one thing that is visible in radar and in the imaging system and the
VIMS spectrometer and in the DISR instrument. And that's going to be
important when we come back to how we actually located the DISR landing
site.

So on left-most side, you see those, what we call tiger scratches, but
they're longitudinal dunes of material which is very fine grain relative
to the 2.1-centimeter wavelength of the radar. And so, they appear dark
as the - the radar basically vanishes within them.

The feature in the center is a very large impact structure; this one
about 400 km across. And we've seen a number of impact features. There's
another one in the upper-right corner of the full radar (shot) that's
shown at the top of the slide called (Cynlap). And remember that we'll
come back to that feature as well.

And then on the right-most part of the enlargement in Slide 13, we see
what looked like a fluvial or river valleys. These are similar to the
kind of crisscrossing fluvial patterns that we see in the deserts of the
Earth. And we'll come back to those.

So, from the first two passes we see tectonism and volcanism impact
dunes and something that looked like drainage pattern.

Next slide is Slide 14.

This has an animation attached which is a release of the Probe which is
in the directory. And so on Christmas Day, the Probe was released.

And the next slide, Slide 15 shows the stages of descent on the multiple
sets of parachutes as this - as the Probe was released and encountered
the atmosphere and then spent a couple of hours; 2-1/2 hours in fact
down to descent. And as shown on the slide there, we continue to receive
the radio signal for over three hours and they probably - the spacecraft
probably survived even longer than that.

So, next slide shows the schematic diagram of the Probe. And what I want
to talk about here is the descent (unintelligible) spectroradiometer.
This is remarkable instrument provided by the University of Arizona;
Marty Tomasko is the Principal investigator.

And it has upward-looking and downward-looking ultraviolet
spectrometers, infrared spectrometers, visible spectrometers,
nephelometers, sun trackers. It's quite a gold mine of - I think it has
14 optical channels and most of them all worked providing a whole
variety of data sets.

The one I will talk about today are depicted there, the three imaging
systems which take views \-- side-looking imager looks out for the
horizon, the medium resolution imager down at about 45, and high
resolution imager about 6 degrees off of (Nater), the bottom edges of
that image.

So these three cameras are fired simultaneously in what we call
triplets. And as the Probe spun, the idea was to collect panoramas as
this set of triplets basically marched around as the Probe rotated.

On the next slide, Slide 17, shows the descent was far more complex than
we had anticipated. The direction of the Probe actually started out and
reversed and to this day no one really understands how that could be -
the (VIMS) which produce the rotation were certainly mounted in the
right direction.

It turns out that because of the reverse rotation and because of the low
signal, DISR lost track of the sun. And so - also the wind speed we
expected moved the Probe at a fairly high rate across the surface of
Titan were much lower than we expected. So, the probe basically sank
almost vertically down in the lower part of the atmosphere when the
surface became visible.

And then the wind direction actually reversed in the last 7 kilometers
before landing. The parachute was randomly tilting and experiencing all
kinds of chaotic motion. And so when we gout our data set the first
evening, out of 6 degrees of freedom which would be the latitude,
longitude elevation and then the orientation - the three orientation
angles, we basically only knew the altitude.

So, the next slide which is Slide 18 shows something you've all seen,
which is the high resolution mosaic from DISR, and as I said because the
wind speed is quite low, these mosaics as we flew closer and closer the
surface covered the same area.

And there's good and bad in that. And the bad in that is we saw less
total area with the imaging system. The good in that is that we get
higher and higher resolution data of the same region allowing us to
better interpret what we're seeing as we go down in - to higher
resolution.

The next slide shows how we went about early on reconstructing the
motion of the spacecraft from the images alone. You can see the little
mosaics are made up of the higher resolution images taken in the last -
looks like six to nine minutes of descent.

And we know that - as I said the bottom edge of the high resolution
imager is 6 degrees off of (Nater) if the Probe were hanging (plum).
However, we know the Probe was not hanging (plum). And so those little
black arrows show where the intercept of the axis of the Probe is with
the ground.

And so by building up mosaics, we can see the direction the spacecraft
was moving and the oscillations that it was experiencing and actually
build up motion history and a directional history.

And see - you can see that red vector that you get from -500 and 44
seconds to -386 seconds gives us the direction of motion. That little
mosaic has dropped into the big mosaic in the lower-right corner. And
you can see that in the last several minutes, the Probe was traveling
back toward the northwest.

Now, the prevailing winds through most of the descent was from west to
east. And so - the next slide shows then the construction of the final
part of trajectory. As I said it was coming down traveling to the east
and when it encountered apparently a boundary layer about 7 kilometers,
you can see that scale on Slide 20, the wind actually reversed and moved
back to the east and - to the west and actually to the north.

Now, there are actual (Meridiana) winds. (Tucano) has modeled some of
these and they're (tightly) induced and these are not totally
unexpected. But they were at the time to ask particularly when we were
trying to build a model of the descent trajectory.

So, the next two - time steps are these two movies. In the first movie -
they're wonderful movies provided by Erich Karkoschka and I encourage
you to spend some time looking through them.

The first one basically is - shows the images as the descent occurred in
sort of a forward-looking direction eastward looking direction. The
second movie is designed to show you the spacecraft orientation
parameters, data links, parachute orientation. It's really a wonderful
movie for us space cadets if you will. I love it. It's just a wonderful
way to see the complexity of the entire descent.

Now going on to the next slide, which is Slide 23, again on the
right-hand side, this is something that all of you probably saw the
morning of the January 15, just a day after the encounter. And the
remarkable evidence of what looks like drainage channels cutting down
through the bright terrain on the right-hand side there, if you look at
those channels, you'll see that they're fairly high order than the
dendritic patterns. In other words, they branch and the branch is
branched and so forth up to fifth and sixth order which suggests a
distributed source meaning rainfall.

In other parts of the mosaic, we see very stubby networks suggesting
perhaps spring-fed processes. So, there's evidence in the data set of
both rainfall and spring and the candidate obviously for this is methane
rain forming these.

Now, the dark material in the channel is not liquid. It is - although,
those are stretched to make them very dark, that - the difference in -
albeit or between those and the surrounding terrains is actually quite
small probably less than a factor of two. And they are not dark enough
to be methane liquid. Most likely the dark materials in the floors are
legs of hydrocarbon that had been washed off of the bright materials.

Now going to the next slide, we've been able - because the images are
acquired as the Probe descends and we acquired images from a whole
variety of directions and altitudes of the same parts of the terrain,
this allows a compilation of stereographic models. And this is a digital
elevation model of that region which looks like a shoreline between the
dark planes and the bright highlands.

The release shown in this model is the order of 200 meters; the lowest
regions being in the dark planes which we believe to be carved by
fluids. They have scoured fabrics and - that you would expect from
floods across a plane like that.

The next slide is an animation which some of you may have downloaded.
And again, this is built up from the five stereographic models.

The remarkable thing about this movie is this is - a vertical
exaggeration has not been doctored. In other words, this is one to one
vertical. And so the very, very rugged on nature of the bright highlands
in the small block of 3x5 kilometer area is actually with slopes of the
order of 30 degrees which is the angle reposed. So, these terrains are
extremely rugged highland areas.

Going to the next slide, I want to turn now to the process by which we
try to find the landing site in the radar T8 coverage which is shown in
the lower-left corner.

The red circle shows where we believe the Huygens landing site would be.
The upper-left corner is an ISS image from Cassini. At the lower-right
corner is the VIMS image of the same of region.

All three of these \-- ISS in the upper left, the radar in the lower
left, and the VIMS in the lower right \-- are to the same scale. That
is - the top to bottom scale is about 300 kilometers.

So, our thought was it would be trivial. We'd simply identify the DISR
mosaic which is shown there in the upper right into scale, the little
inset next to it, slide it over the radar image and Eureka we'd know the
landing site.

Well, it turned out when we compared it as you can see the lower-left
image wit the lower-right or upper-left, that the radar images don't
resemble the visible images to a large degree. As a matter of fact it's
very little.

If you look to the right of the red circle, about four-circle diameter,
you'll see a circular feature with a little tab pointing out at about 10
o'clock. If you trace that feature, you can easily see it in both the
ISS and the VIMS image. So, a few things do correlate but not very many.

In general, the bright materials that we see in the visible images are
randomly bright and dark in the radar images. So that set us on a path
trying to figure out what does in fact correlate between the visible and
the radar images.

So the next slide, we'll show the T8 coverage. You see where the Huygens
landing sight is there. And in the T8 coverage, we saw enormous sand
seas, you know. Ralph Lorenz et al has published a paper in Science
recently describing this very, very ubiquitous - what looked like
longitudinal sand dunes that drape the many parts of the equatorial
regions.

So these typically are 10-kilometer spacing, crest-to-crest and they run
for hundreds of kilometers in cases. For the most part, you can see that
they are (sleep) around and are interrupted - deflected by the bright
materials, which we believe to be bright hills or mountains in the data.

So coming back now, which is Slide 29, let's start looking at the - a
little more of the correlations between the radar properties in the
upper left. And remember, the crater (Cynlap) left I mentioned early on
that we saw in the T3 coverage.

You can see in the lower left, a VIMS color composite in which blue is
set to 1.3 microns, green, 1.6 and red 2.0 Microns. These are three
methane bands. And let's look at the next slide which shows the windows
through the absorbing gasses and they're basically - the primary
absorber in the atmosphere is methane, CH4, and although nitrogen, which
is the primary (meteoric) gas - the carrier gas and a full amount of
carbon monoxide also are absorbers.

I've - I lettered the three bands I just mentioned in the VIMS, a 1.3,
1.6 and 2.0 microns are lettered blue, green and red in that diagram. So
those are the window that we're looking through.

So the next slide returns to the composite - VIMS composite. And if you
look now, you'll see that the dark materials in VIMS in the lower-left
corner are broken into two units that we'll call dark brown and dark
blue. The bright units in this image don't show a lot of
discriminability but we've been able find spectral discriminability in
them as well.

So what is the dark brown and dark blue possibly related to? The next
slide shows an enlargement of the (Cynlap) crater region. And you'll see
that to the outer margin of this large bright radar or bright region
around the crater that's probably associated with the ejecta blanket and
may be associated with a cloud that was wind-swept by the atmosphere
during the ejection of material from the surface; this big, parabolic
form.

Outside that margin, you see a pervasive set of the dark tiger scratch
sand dunes. We found that throughout the equatorial region, the dark
sand dunes seen in the radar correlate one to one with the dark brown
unit that we saw earlier on. So going to the next slide, which is a
single VIMS cube, you can see that dark brown unit wrapping around
(Cynlap) which is in the upper top margin on the right side of that
crater.

So going up - the next slide shows what might be causing this
distinction of dark brown and dark blue. Water ice which is - we're now
looking at Slide 34. Water ice, this is a spectrum of water ice shown in
black. It's a 50-micron grains of water ice provided by Bob Brown who is
the (PI) of the VIMS Team at 120 Kelvin.

And you can see that water ice has strong absorption bands at 1.6 and 2
microns. And if you look at the dark blue and the dark brown units which
are shown there, you can see the dark blue actually reverses its
brightness from 1.3 to 2 microns relative to the dark brown units in
that slide. The suggestion is that the dark brown units have less water
ice than the dark blue units which maybe dominated by water ice.

Going on to the next slide which is a three-dimensional model, for those
of you that have downloaded it, in which a cluster diagram is presented
in 1.3, 1.6 and 2 microns. And what you'll see when you look at that
movie is that the cluster in - that is breaking apart, these bright and
dark units, is extremely flat in three-dimensional space suggesting that
there are only three components involved in this model.

Next slide, which is Slide 36, shows those components mapped onto the
surface, this has been interpretive if water ice is controlling the 1.6
and 2.0 micron features in bright and dark (solens) are controlling
basically the brightness away from the origin in that cluster - 3D
Cluster.

And so the interpretation is that the very dark blue in those units,
which correlate now with the sand dunes are the dark dry (solens).

So let's go back now to Slide 37 and returning to try to interpret where
the DISR landing site is.

So we've concluded that the dark sand dunes ought to be visible in both
VIMS and in DISR and ISS and in radar. So let's go to the next time step
and you can see now an enlargement of the radar image from T8. The red
circle is where we believed based on navigation that the Huygens landing
site should be.

And you can see that north of the landing site, there are a few dark
isolated dune streamers. Those are about 30 kilometers to the north. And
in fact, a young scientist at U of A, Jason Perry, actually pointed this
out early on and the site - remember the side-looking imager on DISR
looks out toward the horizon from about 45 degrees below the horizon, up
to the horizon. And so the side-looking imager, you ought to be able to
see those individual dunes.

So going to the next time step, which is 39, we're now zooming in on
those streamers. The two of interest are just above center, about a
fifth of the slide. And the next slide shows a mapping of the
side-looking imager from DISR this or onto this radar image, two of the
images.

Next slide, we had another image. And remember I said that these images
were acquired as triplets in which a side-looking imager, a medium
resolution imager and a high resolution imager pictures were acquired as
a triplet. So these are glued together.

And as many of you know, we lost a lot of the DISR coverage owing to a
transmission - a mistake made in coding the sequences. And so we lost
the medium resolution imager in this case. However, because the
side-looking imager and the high resolution imager are locked together,
we can navigate and control the high-looking imager and that
automatically places the high-resolution imager in the right place in
that image.

So going on to Slide 42, we had another one, which is a side-looking
imager with a high resolution imager. You had another one in Slide 43.
And finally we can tie the mosaic onto the radar coverage.

And so it was owing to the fact that the sand dunes, these dark sand
dunes would be visible both in radar and in all three of the optical
instruments that allowed us to do this navigation of the landing site.

And finally, Slide 45 shows an enlargement. In 46 we removed the mosaic.
There's not a whole lot there; you can barely see the edge of the bright
highlands. But if - you can see the difficulty in just taking a DISR
mosaic and arbitrarily pasting it on a place.

We now believe that the DISR landing site is probably or the Huygens
landing site is probably located to about 5 to 10 kilometers, probably
closer to 5.

So now going on to the next slide which is the Word slide, the summary
of the VIMS and radar correlations. These dark longitudinal dunes
clearly correlate with this dark brown unit seen in VIMS and believed to
be high and dark (solens) and poorin water ice relative to the other
materials. That makes these dark sand dunes granules of dark (solen)
that are being (saltated) across the surface.

Also Huygens landed in a region - in the bright regions and dark blue
units. So there were no sand dunes in the immediate vicinity of the
Huygens landing site. The nearest sand dunes were about 30 kilometers to
the north. So we would expect the materials at the Huygens landing site
to be those which are corresponding to the dark blue unit which we
believe to be (solens) that are richer in water ice. And in fact the
DISR infrared spectrometer data published by Tomasko et al suggest water
ice present in the surface materials. So at least we're beginning to
sort out one or two of the units on the surface.

And coming to the next slide, which is Slide 49, Titan - as I mentioned
early in the talk, Titan's geology is looking like a Lexicon out of a
geological textbook. We see evidence for volcanic processes, faulting,
and tectonism, pluvial processes \-- that's P-L-U-V-I-A-L, which means
rainfall \-- and (curving) of dendritic channels. We see things that
look like spring-fed processes and we see a volcanic pancake dome
suggesting volcanic processes.

So - but until the end of July, we had not seen anything that convinced
us that we were actually seeing liquids on the surface.

Now coming back, so Slide 50 is a ISS image. It's actually an animation
of several images showing a kidney shape feature near the south polar
region that the imaging system \-- Caroline Porco is the (PI) \--
image - about a year ago now.

And this large dark shaped features actually the size of Lake Ontario
and the ISS Team suggested this might be a lake although - because the
difficulty in seeing through the atmosphere and getting a good measure
at the surface (albedo) and so forth, it was difficult to certify.

So let's come now to the next slide which just shows - which shows all
of the radar coverages with the addition of T16 that was acquired in
late July. And this was the one that recently you've seen from the Radar
Team suggest we may in fact now be seeing this methane or methane-ethane
lakes up in the - very high latitudes.

The only - the darkest of these, going to the next slide which is Slide
52, occur at the very highest latitude of this path. And these - if you
looked at these in a histogram, you'd see that the darkest parts of
these bodies that look like (light) features are very, very dark.

The Radar Team is working now to analyze how dark these really are and
if the case really can be made that we're seeing liquids but the
preliminary indication is that they are dark and quite likely liquids
are much darker than anything we've seen elsewhere particularly in the
equatorial and mid-latitude regions.

Notice that in the lower tier which is a part of the path and I believe
that's to the right-hand side, you see, many disconnected little lakes
and that suggests that perhaps intersection of a rough surface with a
methane water table is at work, sort of like mini - like a (slot) in
which the water table intersects to the surface.

The upper images shows (stubby) drainages that go in places and a lot of
these are in very deep circular depressions or quasi-circular
depressions. This may in fact be called (Aras). They are filled with
fluids.

So perhaps rain, perhaps tectonic volcanic control of the depressions,
and perhaps the sub-surface are saturated and the water table or methane
table basically intercepts the surface.

More to come on that, Radar Team is busy analyzing the results and
writing this up for publication.

But in T19, we - after seeing the T16 coverage, we elected to move the
T19 coverage. We have a choice of either looking to the right or to the
left of the spacecraft, to the right or left of the ground track.

And we elected to look at high latitude with T19 which will be coming up
in early October, and you can see that it will perhaps intercept a few
of the "lakes" that we're seeing at very high latitude in T16. If that's
the case, one of the things that we'll be looking for is changes in
patterns. These lakes may actually have wind ripples on them. And if
those were to change in form, that would certainly be another piece of
evidence.

And the other question is, whether or not this "lakes" that appear to be
pervasive above 70 north are even more abundant in - at higher latitudes
where T19 will cover. So stay tuned for that.

And so in summary, for a planetary object that I for one expected to
find the most bizarre and new processes - unimagined processes, the more
we look at it, the more it looks like processes that we see in
geomorphology and geological settings on the earth, albeit that the -
that chemistry and the temperature are shifted enormously.

And so questions: Are these really lakes? Where is the rain occurring?
Is it occurring in the polar regions? Is that why we see evidence of the
lakes' high latitudes? Will there be - are there monsoonal seasons as
the sun moves from latitude to latitude? As you know, Titan has seasons
like the Earth and Mars owing to its tilt - of its rotation axis
relative to the sun.

Currently the sun is at the - in the southern mid-latitudes. In about
2010, it will cross the equator and move north. And we'll be looking to
see if the weather patterns change and we see evidence of rain elsewhere
on the planet.

So thank you very much.

Trina Ray: Do we have any questions?

Man: Where can we find the animations he mentioned?

Trina Ray: Those are on the password-protected site for the CHARM
telecon and in the original email that you got there is all the contact
information to get to that site is at the bottom.

(Ken Kramer): Yes hello. I have some questions. This is (Ken Kramer).
You mentioned with the T16, can you make (an estimate) how deep these
lakes maybe?

Larry Soderblom: How deep they may be?

(Ken Kramer): Yeah.

Larry Soderblom: The - it's possible that in some places we're seeing
where the lakes don't look as dark as - they seem to vary in their
darkness, (Ken), it's possible that we're actually seeing the radar
reflecting off the floor of the channel at the bottom of the lake
because methane can be quite transparent to the radar.

In those cases, it might be tens - several tens of meters deep. In the
very darkest parts, they might be a hundred meters deep. But again, this
will await further analysis and we have experts on the Radar Team
looking at the radar properties they expected.

But one of the suggestions is that we're actually seeing reflections
from the floor of some of these lakes which is causing variations in
their appearance.

(Ken Kramer): That's really helpful, you know, and I'm looking at this
big lake-like feature that you're saying that has channel on the top
right. You're saying that little (squiggle) is the bottom? Wow.

Larry Soderblom: Yes. If you actually look at that image that's two
pieces of the (slough) above one, above the other, the darkest parts are
the lake in the upper-left corner. Then there's a lake that's kind of in
the middle of that (slough). It's kind of irregular shaped with rounded
margins that has a very dark spot in there.

And then the upper-right lake, you actually see a dark part in the
largest lake. Dark part sort of left of center...

(Ken Kramer): Yes.

Larry Soderblom: ...but then you'll see what looked like channels.

(Ken Kramer): That's what I'm talking about.

Larry Soderblom: So one of the notions is that you're actually looking
at the floor through the liquid.

(Ken Kramer): (That's neat).

And the brighter areas, are they - they're higher in elevation,
obviously, I guess, right?

Larry Soderblom: Yeah. And those vary from - I suspect there's a
combination of - some of these bright materials are water ice. The
things that are bright, I didn't get into that, but we see variations in
their infrared properties in the VIMS data suggesting some of these
bright areas are water ice perhaps (cleansed) by the rain.

In others, maybe bright (solens). So one idea is that perhaps the
(solen) which is snowing out of the atmosphere may start out as bright
material, (goes) to surface and then as it's moved and washed and blown
around, it aggregates into coarser and coarser particles that become
dark. This is similar to processes that occur on Mars as well.

(Ken Kramer): And these lakes are - so there is some question in your
mind then as to whether these actually are lakes then?

Larry Soderblom: I'll give them 90%.

(Ken Kramer): Ninety percent? Okay. And...

Larry Soderblom: But there are a lot more - there are folks on the team
which are less and more conservative. So we're really excited about
getting this new coverage in early October. It's - as a matter of fact
it's right - adjacent to the DPS. So we may be able to have something
available.

(Ken Kramer): Yes. Because the public press release that's coming out
like this - it's like greater than 99% chance that this is a lake. So,
okay, so you're still a little bit hesitant.

Larry Soderblom: Yeah. But you know how things work with
(unintelligible). There's a tendency to convert qualifiers to - and
caveats to be deleted.

(Ken Kramer): Right. And you think this - if they are left in there,
like this is mostly methane and maybe just a little bit of ethane. Is
that right?

Larry Soderblom: Boy, that - I think that we don't have any direct
evidence although we know that ethane has to be there because it's
generated in a (photochemical) chemical process and we know it will be
immiscible. I don't know how much ethane was detected in the GCMS or
whether that's been refined. But most of what we're seeing was methane
as far as the hydrocarbons.

(Ken Kramer): Yeah. That's why I'm asking because I asked this question.
They haven't found much ethane in the GCMS is my understanding from one
of these other telecons.

Larry Soderblom: And that's - I think that's the case. But I think
(Hunter) is going to do this in a month. Is that right, Trina?

Trina Ray: Yes. In fact, our very next CHARM telecon is all about
Titan's atmosphere.

Larry Soderblom: So ask them that question and ask them where the ethane
went, yeah.

(Ken Kramer): Yeah.

Man: If these are not lakes, what could they be?

Larry Soderblom: They could be solid. They have to be very, very smooth
for 2-centimeter radar to be reflected away like a mirror. So -which...

Trina Ray: Could they be frozen lakes, Larry?

Larry Soderblom: Well, frozen what is the problem. More likely they'd be
lakes that may be - have - were very flat and the liquid basically just
retreated to the subsurface. I suppose that they were some sort of
volcanic eruption of material that was extremely fluid and formed a
surface that could be like an ice sheet. That's conceivable. But, you
know, the easiest thing for them to be is liquid methane.

Also, the fact that they're so highly concentrated in this latitude ring
north of 70 degrees doesn't suggest to me that they're, you know, a
volcanic process, but some sort of a natural process related to the
atmosphere; a lot like rain in the polar region. As a matter of fact,
it's been suggested that the polar regions may well be experiencing a
lot of rainfall now.

(Ken Kramer): What's your opinion about this rainfall now? The latest
that I've read is that it could be a very - there was a mist coming
down.

Larry Soderblom: Right, right. That's - those are a couple of vapors
that came out just the end July and Nature, was it?

(Ken Kramer): Yes.

Larry Soderblom: I'm not sure. I think they were talking about mist
everywhere. One of the things that the DISR data has shown is that the
(solen) particles as they fall to the atmosphere may change their
optical properties and become very shiny towards the bottom.

And so, perhaps the stuff is nucleating on them, you know, forming icy
coatings. But as far as rain, I don't - the problem is finding a - the
problem all along is finding direct evidence for liquid whether it's
rain or on the surface in the form of lake.

What do you actually look for and everything we've come up with, you can
find alternative explanations although I think the alternative
explanation for the very, very high latitude concentration of these
lake-like features is what makes me think that it's 90-10 that they are
liquid.

(Ken Kramer): Well, to follow up on that, what would a ripple look like
if that's what you're looking for?

Larry Soderblom: A ripple, like a wind ripple?

(Ken Kramer): A water ripple, right? That's what you're looking for and
maybe a wave?

Larry Soderblom: Well, the ripples on the surface would be ripples on
the surface of the methane liquid.

(Ken Kramer): That's what I'm talking about. So what would they look
like?

Larry Soderblom: They'd look like a deviation where instead of seeing
they're really dark, you'd start to see - because the waves are
tilting - are facing the spacecraft and the radar would come right - a
small fraction would come directly back.

So you see these in Earth orbital radar, of places in the oceans in the
Mediterranean and so forth in which you see all kinds of patterns which
are related to ripples and wind (wakes).

And so the question is can we take some images with the radar in October
of the same lakes and see if in fact the patterns have changed.

So - well, Trina?

(Ken Kramer): Can we - can I - you've got time for a few more questions?

Larry Soderblom: Sure.

(Ken Kramer): Great. Can we go to Slide 11 which was TA path. Okay, on
the right-hand side, I think you said you might come back to this. Now,
in light of the T16 path, these dark areas, you see these really dark -
yeah, we see these dark similar kind of dark areas. What do you see or
thinking about them? Are they...

((Crosstalk))

Larry Soderblom: On the lower-right corner...

(Ken Kramer): On the lower right, yeah.

Larry Soderblom: ...the same - CC, the Cat, was that we're looking at
Slide 11?

(Ken Kramer): Yes, on the lower right exactly.

Larry Soderblom: If you - as a matter of fact, I - we did this in the
T16 path and we basically made a histogram of the brightened
(variations) within the entire path. And you basically see the very
bright materials as a mode sort of the - in the very dark lake-like
things, the pole is a mode right against the floor of the signal.

And then you see variations of dark materials which is sort of midrange.

Well, this set of data here is fairly midrange. In other words, they've
been stretched so that the dark materials - these are the dark materials
in this image. But they are very, very much brighter than the dark lake
in T16.

(Ken Kramer): So they are.

Larry Soderblom: Yes. So one of the things that I'm hoping we'll include
in the radar paper on this is a set of image that all stretched the
same...

(Ken Kramer): Yeah. Right.

Larry Soderblom: ...so you can really see that effect. And, you know,
it's like images of the Martian polar region. Everybody stretches them
so hard that things that vary and albeit by 2% from one another look
black and white. And it's a, you know, we're taking advantage of the
fact that these cameras have extremely high signal and noise, but it can
be very misleading if they're just (auto-stretched).

(Ken Kramer): Yeah. You're (fooling) yourself basically.

Larry Soderblom: Yeah. So I think it'd be really good if we can get a
set of these radar passes in which they're sort of stacked side by side.
They're all stretched identically.

Anita Sohus: Hey Larry. This is Anita.

Larry Soderblom: Hi.

Anita Sohus: Is there a chance of any (colorization) or anything to help
people interpret this a little better?

Larry Soderblom: There are some tricks. This is getting away from my
field. So I'm going to hesitate to go there. I don't - I'm not sure the
data are there, but by looking at different angles of reflection off of
these surfaces, there may be a way to use the radar to get a better
handle of sort of the reflection as a function of a mission angle from
these things; incidence in the mission angle if you will.

So by getting all the data that we get from T16 and T19, we may be able
to see more - confine the optical properties or radar properties. But
the experts on the team will work that problem.

Anita Sohus: Who would that be?

Larry Soderblom: Well, let's see. People like Phil Callahan, (Brian
Style) (unintelligible) those folks.

Anita Sohus: Okay. On that Slide 11, on the left that...

Larry Soderblom: Uh-huh.

Anita Sohus: ...looks like a circular structure, is that a
(unintelligible)? Can we have an estimate of the...

Larry Soderblom: We think it's actually a raised - we see those on Venus
and they're called pancake domes.

Anita Sohus: Aha.

Larry Soderblom: So if you sort of imagine a flapjack laying on the
table, the notion is that they are produced by a viscous eruption that
just oozes out.

Now, we don't have any direct evidence on the topography other than the
radar shading around the margin. But in the case of Venus, they're
clearly standing up above the surface. It looks just like this.

Anita Sohus: And do you have a diameter estimate on that one?

Larry Soderblom: Typically, the radar (sloughs) are about 150 kilometers
wide in their narrow part. So that one's probably like that.

Anita Sohus: It takes some time to get to interpret these, doesn't it?

Trina Ray: That's kind of a good number to memorize, sort of the width
of the radar (swat) is about 200.

Larry Soderblom: Right and they go up to like 400 towards the end.

Trina Ray: Right and the length is like a thousand or something.

Larry Soderblom: They're really long and you know that's been really
exciting because the radar, like all the instruments on Cassini, has
worked so well. We've been able to get data from higher and higher
altitudes and increased the coverage. And that's been really fortunate.

Trina Ray: Do we have any other questions?

(Ken Kramer): Yes. Can I ask about Slide 19 and 20, please?

Larry Soderblom: Sure.

(Ken Kramer): Okay. Let's look at Slide 20 first. The height there,
that's kilometer. Is that right?

Larry Soderblom: Yes.

(Ken Kramer): Okay. And the lower axis, is that similar? Each one of
those is about - the stick marks about a half kilometer or so?

Larry Soderblom: Well...

(Ken Kramer): Because I'm looking at your Slide 19 and 20 and 19 looks
like it's really traveled along because...

Larry Soderblom: Right.

(Ken Kramer): Because I look at 20, it doesn't look all that long, (so
this)...

Larry Soderblom: I'll tell you what. The right thing to look at is
Nature, December 8, 2005...

(Ken Kramer): Uh-huh.

Larry Soderblom: ...Tomasko et all. And I think (Bashar Rif) put in a
model in Figure 2 that shows the actual - actually, if you look in
Figure 1, you can see the \-- you have to use a microscope \-- but the
reversal, the total distance of the scale in the bottom in that, I have
to look it up, but it's more like a kilometer on the full side of those
things marked "East" and "North".

(Ken Kramer): Right. Yeah, I'm thinking exactly it's more than...

Larry Soderblom: What happened is the, you know, the wind speed's
dropped to like a half a meter a second. Total distance that the Probe
traveled back on itself was only in the order of a kilometer, I believe.

(Ken Kramer): Oh okay.

Larry Soderblom: So you need to view that as sort of schematic. It looks
like maybe 2 kilometers, but not very far.

(Ken Kramer): Are there, let's see, to go to that kidney-shaped feature,
Slide 50, are we going to be looking at that again in another path to
get some more data on - although that may or may not be a lake?

Larry Soderblom: Probably not until the extended mission. Trina, do you
know anything about that?

Trina Ray: Let me look to see...

Larry Soderblom: As far as I know...

Trina Ray: I thought we had a radar path near there, T39, but I'm not
positive.

Larry Soderblom: I don't think there's anything in the southern...

Trina Ray: No. Yeah, I don't see anything that's going to hit that lake,
but it does get into the area.

Larry Soderblom: Yeah. We're really hoping that in the extended mission
that we can get into some really neat orbital configurations that will
allow us to get more coverage in the polar region.

(Ken Kramer): So - did I understand you right, there's not going to be
any radar then in the south?

Larry Soderblom: I don't...

Trina Ray: No. We have a few. We had T7, we had - that went pretty far
south. But we lost half of that. Then T39 goes even further south than
that. And then we have a little bit of T36 that gets right down there
and a little bit of T41.

(Ken Kramer): So there may be some radar path at the same latitude as
what we see in Slide 51.

Larry Soderblom: Into that - like T16 and T19?

(Ken Kramer): Yeah.

Larry Soderblom: Yeah. I don't think that we have anything like that,
but Trina is looking at the map.

Trina Ray: Yeah. You were talking about the South Pole. Was that right,
the question?

(Ken Kramer): Yes. I'm talking about the south, right.

Trina Ray: Yeah. Yeah I've - the numbers that I looked up were for the
South Pole. We do also have some more northern passes. T19 is a good
example. And then we have a series; so T23, T28, T29, T30. Those are all
North Pole passes.

((Crosstalk))

(Ken Kramer): Yeah. We're looking for about 40% coverage with the radar
in the...

Trina Ray: Oh no, about 20 in their prime mission currently.

(Ken Kramer): Oh 20?

Trina Ray: Yeah.

Larry Soderblom: We may get a little more than that. On the other hand,
you know, we have lost pieces of passes going to, you know, things that
happened. And the real hope is the extended mission is going to give
us...

Trina Ray: Maybe another 10% or more.

Larry Soderblom: Yes. We might get up to 30%, 35%.

Trina Ray: Extended mission maybe more than that. The one thing we do
know is that we know at the end of the Cassini mission, we will not, you
know, we will not have it covered. So we have to go back.

(Ken Kramer): Hey, what's your opinion of - this brings up a great
question about follow-on missions to Europa or Titan or what about a
Titan balloon?

Larry Soderblom: The Titan balloon is a - well, okay, Europa is
exciting, but extremely difficult because the radiation environment and
so forth, right?

And also, if you really - whereas Titan is maybe one of the easiest
things to get to in that sense. And so, you know, if you wanted to find
something that's easy versus difficult, if they both have identical
scientific merit, let's just say that they do, so we won't argue among
Europa and Titan, then Titan certainly is a lot easier.

((Crosstalk))

Anita Sohus: So what year would you think Larry, that we might be back
at Titan if you have to, you know, put a bet down?

Larry Soderblom: Hmmm.

Anita Sohus: With your vast experience and knowledge.

Larry Soderblom: Well, it kind of depends on what happens in politics in
the next few years. But maybe 2015.

(Ken Kramer): Can you do it within the discovery program or do you need
a much more expensive...

Larry Soderblom: It's going to require a flagship mission.

(Ken Kramer): okay.

Larry Soderblom: Yeah.

(Ken Kramer): It's interesting because I guess NASA has always promoted
or the scientists Europa as the place to go until your colleague
Jonathan Lunine...

Larry Soderblom: Well, there was a caveat when we started looking at
Titan, Europa and other targets back six years ago. And the answer was
let's wait until Cassini before we try to - to make that decision. So we
now have Cassini. So, what do you think?

(Ken Kramer): Oh I think we should go to both actually. I'm a chemist
myself and I think they're both fantastic.

Larry Soderblom: All right. Well that's - that's a very politic answer.

(Ken Kramer): No. Well, the reason is because water, I mean liquid water
and life, you know, you got a better chance with Europa.

Larry Soderblom: Yeah that's true.

(Ken Kramer): But I understand that there's a radiation problem and can
you even get through the ice, you know, it's a couple of kilometers. So
that's a real question whether you could do that...

Larry Soderblom: Yeah.

(Ken Kramer): ...whereas I think - I agree that the balloon going to
Titan and the way you've presented it is much - is a very attractive and
from a chemical standpoint is fantastic. We're not going to find life at
Titan, I would guess, but a lot of interesting chemistry.

Larry Soderblom: Yup.

(Ken Kramer): So, I mean I'd like to go to both actually; plus Sirius
would be another one...

Larry Soderblom: Sure.

(Ken Kramer): ...or Enceladus for that matter.

Larry Soderblom: Well it's obviously exciting.

Trina Ray: I'm for all of them.

(Ken Kramer): I'm for all of them.

Trina Ray: Do we have any more questions?

(Ken Kramer): Yeah. I got one last question about Slide 36.

Larry Soderblom: Okay.

(Ken Kramer): Okay. I don't understand what is the difference between
the blue and the green.

Larry Soderblom: Okay. Do you have a, you know, Slide 35 is the
animation.

(Ken Kramer): Yeah.

Larry Soderblom: (Buster) something.

(Ken Kramer): Great.

Larry Soderblom: So, basically what that is is if you play that
animation, you'll see that that triangle has three end-members \-- water
ice, dark (solen), and bright (solen). And everything lies on the sheet.
So what I basically did there is I assigned that to a trinary diagram in
which water (excess) is red in this model.

The dark (solen) is blue and the bright (solen) is green. So, where you
see a red and blue, you're going to see magenta or purple and so that
would be dark materials that are water rich.

(Ken Kramer): The dark materials are water rich. Oh I see. And the
bright materials...

((Crosstalk))

(Ken Kramer): ...are water poor for them?

Larry Soderblom: Then the blue materials would be water poor.

(Ken Kramer): Okay. That's what I'm trying to...

Larry Soderblom: Okay. And then the green materials would be bright
materials that are water poor.

(Ken Kramer): Green is water, let me just write this down. You mean
green...

Larry Soderblom: Green that's bright, that's water poor.

(Ken Kramer): The blue is water rich?

Larry Soderblom: Blue is water poor.

(Ken Kramer): Water poor.

Larry Soderblom: So blue and green are basically the dark (solen) and
the bright (solen) without - with less water. Everything probably has
water ice in it by the way. So, we're talking about degrees.

(Ken Kramer): So - well, that's what I'm getting at. What is the
difference between the dark (solen) and bright (solen)?

Larry Soderblom: The - oh probably grain size.

(Ken Kramer): Oh just grain size.

Larry Soderblom: Or chemistry. I mean the (solens), you know, the stuff
that folks have generated early back to (unintelligible) and Sagan,
there are a variety of (solens) you can generate; some of them are dark,
some of them are bright. The fine grain stuff maybe be the bright
(solen). My model is that that starts out as bright fine grain, it's
processed on the surface and coagulates into a larger and larger grains
and - that become darker. And then finally they, because they're
scattering is inhibited, and finally they (saltate).

So that's just a mental model.

So the stuff that's orange with the bright material that's got water,
more water in it and the purple stuff would be dark material that has
more water in it.

Does that make sense?

(Ken Kramer): Yeah. And I absolutely understand the difference.

Larry Soderblom: And this is just a model.

(Ken Kramer): I didn't quite understand the difference. Thank you.

Man: I have a question.

Larry Soderblom: Sure.

Man: Could you explain why (solen), they don't exist on earth and how
they are actually created experimentally like you had just referred Carl
Sagan's early experiments.

Larry Soderblom: Well they're created by mixing methane and nitrogen gas
and putting them in a plasma chamber and electrocuting them. And that's
the original.

And then there is a more recent papers. I think Imanaka and the folks
said at (AEMS) have done more recent work. But basically, it's due to
the fact there's abundant methane exposed to solar UV at the top of the
atmosphere. And the methane, this is photochemically with nitrogen as
well, you know, CH4 is dismembered and then C2H2 forming methane and
C2H6, the (FA) and C2HC, acetylene propane, all of these heavier things.
And finally they coagulate into a bigger, more complex hydro carbons.

And this is not my field but I can certainly get you a long list of
literature on the subject.

This should be a real good question for (Hunter) next month. To go -
because he understands the chemistry of the upper atmosphere better than
anybody.

Man: Thank you.

Trina Ray: Okay. Do we have any final question?

(Ken Kramer): Could I ask a Mars question?

Larry Soderblom: Sure.

(Ken Kramer): Okay. We're going to be...

Larry Soderblom: Trina was willing to pay for it.

(Ken Kramer): What's your opinion about where we're going to find life
on Mars? Is it better there or should we - if we could direct the Mars
Science Lab there or better at the equatorial regions or I guess regions
or I guess (unintelligible).

Larry Soderblom: You mean polar versus equatorial?

(Ken Kramer): Yeah.

Larry Soderblom: So the polar regions would be a lot of fun because of
the history that's got us the - held in the polar layer of (ice). But
it's probably mostly modern geological history in the last, you know,
hundred million years or less. The external regions, you know, are going
to give us evidence back to two and three billion years ago and that may
be the period in which Mars was warm, wet and may actually be more
interesting from that perspective, from the life perspective.

So, I guess here is the answer again, it's do both.

(Ken Kramer): Yeah.

Trina Ray: Okay. Well, Larry, we'd like to thank you very much today for
taking the time out of your schedule to talk to the CHARM telecon. We
really appreciate it. We've had really series of these talks over the
last couple of years and we all go on this audio recording that we have
several hundred people download and we've gotten a lot of very good
feedback.

So we really appreciate your taking the time. Thank you so much.

Larry Soderblom: All right, thank you.

Anita Sohus: Hey, Trina, can I make a plug here?

Trina Ray: Sure.

Anita Sohus: The Division for Planetary Sciences meeting is one of the
two top planetary science meetings that are held every year and it will
in be Pasadena, California this year; it's October 8 to 13. And we are
planning some solar systems seminars as the best way for faculty and
their students locally and then we're hoping to also make it available
as an online course that people can take either fall or spring semester
online.

So I can send out information about that if anybody is interested in,
you know, actually coming to DPS, give me a ring and I will see if we
can get you in without having to pay registration.

Trina Ray: Sounds good. And this is Anita, right?

Anita Sohus: Yes. Anita Sohus at JPL.

Trina Ray: And then our CHARM telecon for next month as Larry has
already alluded to is Dr. (Hunter Wade). He is the principal
investigator for the ion and neutral mass spectrometer and also an
expert on Titan's atmosphere and he'll be giving us the talk. The
telecon will be on Titan's atmosphere and hopefully some of the history
of how our understanding of Titan's atmosphere has changed which has -
it's changed quite a bit during just the Cassini mission itself. We've
actually had to change the reference trajectory of the spacecraft a
couple of times based on newer and better understanding of Titan's
atmosphere.

So that's going to be a terrific talk. That will be next month, the last
Tuesday of the month as always, at 11:00 am Pacific time and that would
be September 26.

And with that, we'll let everybody go. Have a great week.

Man: Thank you.

Man: Anita, are you still there?

END