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Posted by: jmknapp Dec 30 2005, 11:20 AM

Here's an animation of the Jan. 15 flyby:

http://cboh-t.cboh.org/~jmk/titan15jan.avi

A list of some of the activities:

CIRS_020TI_FIRNADIRCOMPINT_01

Obtain information on trace constituents in Titan's stratosphere. Integrate on limb at two positions POINTING: Obtain information on CO, HCN, CH4. Integrate on disk at airmass 1.5-2.0. POINTING: -y to Titan, x away from sun.


ISS_020TI_MONITORNA001_PRIME
NAC Monitoring of Surface and Atmosphere
monitoring for surface/atmosphere changes; attempt to see surface color variations; monitor limb hazes, 1-3 km/px

MAG_020TI_MAGTITAN001_PRIME
T10 Flyby
T 10 is an interesting upstream encounter with a minimum distance of 2071 km which reaches into the middle ionosphere. Together with T 8 and T 6 it allows to reconstruct the upstream equatorial ionospheric pile-up region. Since it repeats T 8 and T 6 to some extent the priority is smaller than T 6 and T 8, but still in the range of grade one priority.

NOTE: - continuous data rate of 1976bps (32vps).


MIMI_020TI_T10INBND001_ISS
MAPS 020TI(T10) Campaign
Part of 020TI(T10) MAPS Campaign. Investigate micro-scale and near aspects of the Titan interaction by observing during about one hour period around an encounter. With -Y pointed toward Titan, when within 30 minutes of the targeted flyby, optimize secondary axis for corotation flow as close to the S/C -X, +/- Z plane as works with the other constraints on pointing. Also, measure Titan exosphere/magnetosphere interaction by imaging in ENA with INCA (when sun is not in INCA FOV).

RPWS_020TI_TIINTRMED001_PRIME
Titan Interaction - Intermediate
Study the interaction of the magnetosphere with Titan at intermediate
distances for evidence of ion pickup, radio emissions, density profiles,
and the general wave environment. Prefer Langmuir probe within 90
degrees of plasma ram.

UVIS_020SU_USUNOCC001_PRIME
USUN_T10
This is a Titan solar occulation with both ingress and egress.
1) Turn from waypoint to Titan. EUV solar occultation port centered on sun at start time: 2006-015T11:15:00. +X to Titan Center
2) Take data from start time: 2006-015T11:15:00 until 1st activity stop: 2006-015T11:48:00. 3) Take data from 2nd activity start: 2006-015T11:53:00 until activity end time: 2006-015T12:27:00.
3) Turn to waypoint and reset pointing.

MP_020TI_FLYBYT010_NA
2006JAN15 11:41 UTC - 2006JAN15 11:41 UTC
Targeted inbound 2043 km flyby, v = 5.8 km/s, phase = 120 deg

MP_020EA_OCCTITAN020_NA
2006JAN15 11:49 UTC - 2006JAN15 12:03 UTC
Earth occulted by TITAN duration = 14 min; egress = 2006-015T12:04

MP_020SU_OCCTITAN020_NA
2006JAN15 11:49 UTC - 2006JAN15 12:03 UTC
Sun occulted by TITAN duration = 13 min; egress = 2006-015T12:03

CIRS_020TI_FIRLIMB_INTEG_01
Vertical sounding stratospheric compounds on Titan, including H2O. Integrations at 2 locations on the limb displaced vertically. POINTING: -y to Titan, z within 45 degrees of normal to limb.

ISS_020TI_AURORAE001_VIMS
WAC Nightside Imaging
search for and monitor lightning/aurora

Also stealing some of the limelight on Jan. 15, Stardust will return samples from Comet Wild to Earth.

Jan. 15 in space exploration history:

2008: First Messenger flyby of Mercury
2004: MER Spirit drives onto the surface of Mars
2001: Stardust spacecraft flys by earth
1962: Apollo Spacecraft Project Office established

all hail Google...

Posted by: Decepticon Dec 31 2005, 03:14 PM

When does cassini look at a new hemisphere? We have had the same 2 for a while now.

Posted by: alan Dec 31 2005, 11:57 PM

The Feb 27, Apr 30, and Jul 2, flybys ( T11, T13, T15 ) will work gradually farther east. TItan will be on the opposite side of Saturn during the July 2 flyby as it was during Ta.

Posted by: belleraphon1 Jan 2 2006, 12:37 AM

I, too, want to start seeing a new hemisphere, but one advantage to seeing the same area, over and over, is the ability to map changes in albedo patches over time.

ANOTHER reason for extending CASSINI past 2008.

Craig

Posted by: Decepticon Jan 2 2006, 01:28 AM

I welcome additional Imaging and radar passes with open arms.

Posted by: AlexBlackwell Jan 12 2006, 03:53 PM

http://saturn.jpl.nasa.gov/multimedia/products/pdfs/20060115titan_mission_description.pdf

Posted by: ljk4-1 Jan 12 2006, 03:59 PM

Have any surface changes on Titan been seen lately? And I mean surface changes, not clouds.

Posted by: volcanopele Jan 12 2006, 07:30 PM

Thanks Alex. This should be an interesting encounter as we will look at the same area as Ta HIGHRESNA001 at comparable resolutions, but with better camera parameters, which should make the images less noisy. UVIS also has a solar occultation on this encounter, their first.

Posted by: AlexBlackwell Jan 12 2006, 08:17 PM

Is this the same observation with the VIMS ride along (i.e., T10 HIGHRESNA001_VIMS)?

As I understand it, ISS has a pretty cool Titan nightside observation (T10 NIGHTNAC002_PRIME), with very nice, long dwell time.

Posted by: volcanopele Jan 12 2006, 09:03 PM

No, its T10 GLBMAPNLP001. The VIMS ridealong is a series of "postage stamps" across the disk as VIMS looks at a few areas (like Tortola Facula) at high resolution

Posted by: AlexBlackwell Jan 12 2006, 09:32 PM

OK, I went back and saw Zibi's TOST T9/T10 ISS slide presentation and now see the different footprints. Thanks.

Posted by: belleraphon1 Jan 13 2006, 12:47 AM

None have been officially reported that I know of. I am a qualitative observer,
and lack the sophistication of those who can render clean images out of the raws.

But due to the haze, I think it is easy to see changes that are not there or miss changes that are there.

Looking forward to Ta HIGHRESNA001 just to see how improved the viewing may be now that the ISS team has more experience .....

Craig

Posted by: elakdawalla Jan 13 2006, 05:17 PM

Volcanopele, is the ISS team planning on releasing one of those overview maps for the imaging plans for T10? There wasn't one for T9, right?

--Emily

Posted by: JRehling Jan 13 2006, 06:03 PM

If surface changes are seen, and they are not so obvious that any rube can spot them immediately, then I expect that the release mode will be like the martian gullies: The data will be there in the raws where anyone could find it but no one will; then when the team has all the i's dotted and all the t's crossed, they'll announce it. So far, there's been no indication of that.

Many kinds of change, if it did happen, would be fairly difficult to distinguish from meteorlogical clouds or products of changed observation geometry.

Aside from possible volcanic eruptions (and we have no reason to suspect that Titan is another Io), I don't know that I would expect Titan to show much in the way of surface changes in a mere 1.5 years of spotty, and largely long-distance observations. It's clearly a place where it has rained, but most of its surface hasn't even seen clouds pass over during this 1.5 year period. And the mere presence of clouds wouldn't mean rain. And mere rain wouldn't mean surface changes that could be seen at 600 m/pix in mono-filter imagery.

I think there are three kinds of surface change we might see eventually:

1) Volcanic, but Titan probably isn't active enough that we'd "get lucky" and seen an eruption during Cassini's tenure. Earth only has a few volcanos that active. Note, though, that the midlatitude clouds on Titan have a postulated correlation with *longitude*. Potentially interesting.

2) Rain, if/when/where abundant clouds show up. Those may be happening at the south pole about now, but it could be very hard to *see* the effects from Cassini. The pavement gets wet, it dries, narrow streams fill for a short time, basins gain a smidgen of area. It would have to be a lot of rain for us to see that. And we know that nowhere else on Titan is getting more than isolated and somewhat wispy cloud cover. However, that might change as the seasons go by.

3) Global inundation if a hypothesized north polar methane cap were to melt. That would be exciting beyond anything yet seen in solar system exploration. Maybe it happens every 15 years, and Cassini will get to see "wet season" begin in the next six years. Or, maybe no such thing happens at all, and Titan's channels are, like Mars's, "ancient history".

When it comes to extended mission priorities, I think there are two distinct Titan priorities: global RADAR mapping, and long-term "weather" observations with VIMS/ISS. These goals are actually antagonistic, given that Cassini's lifespan will probably be limited by attitude-control supply. The situation differs considerably, then, from MGS at Mars. It might be important to define a long-term budget of thruster fuel that will allow several years of limited operations and then a "phenomenon observation" campaign if a major seasonal event takes place. The ideal extended mission, then, might be to perform only a few more RADAR tracks at Titan, intermittent flybys of Enceladus (maybe one of Iapetus), adopt an orbit that intersects Titan's twice at some distance, and take long-range pictures with the CB3 filter at those two points in each orbit, waiting to see if an event takes place worthy of intensive observations.

Presumably, a full cycle of Titan phenomena would appear in 15 years (assuming the alternate hemispheric seasons are similar) or even 7.5 years (if spring==autumn, climatically speaking). We should hope to have a long period of limited observations of Titan, plus "another bullet in the chamber", in terms of attitude-control, in case something happens we want to scrutinize. If the latter happens, we have the story of the century (for planetary science). If it doesn't, then a new priority in 2019 (more RADAR tracks...) could spend the "reserve" with a new mission goal. Assuming that such long timelines are feasible with austerity conservation of the craft's fuel in the meantime.

Posted by: JRehling Jan 13 2006, 06:05 PM

Call me biased, but I like to think of this as "Cassini occulted by Titan".

Posted by: volcanopele Jan 13 2006, 06:20 PM

None that I am aware of. Many of these Titan encounters that don't cover "new" terrain may not require to much press coverage.

Posted by: Decepticon Jan 13 2006, 06:45 PM

Volcanopele Will there be a refreshed Titan Map released soon? I'm curious as to how much refined the images are now with multiple flybys.

Posted by: volcanopele Jan 13 2006, 07:24 PM

hehe, um not in the immediate future. The issue is that I want it to be the last version for at least a year if not longer, so I am trying to put as much data and have it be as "clean" as possible.

Posted by: David Jan 13 2006, 08:03 PM

Titan's northern hemisphere ought to be in half sunlight (beginning of northern spring) by the end of 2009. If Cassini could stay operating for the next decade after that, we should be able to see all of Titanian northern spring (2009-2017) and part of Titanian northern summer (2017 to early 2025).

Posted by: ugordan Jan 14 2006, 10:44 PM

Interesting raw image http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=60312.
Haven't seen 8LSB conversion mode used in a while. I'm wondering of its usefulness here, obviously it cheats a bit by returning only the lower 8 bits of the image DNs and no lookup table is used. Having a pretty smooth intensity gradient like here permits one to recover the full 12 bits (since no LUTs were used) with a bit of work, but is it really worthwhile?
What is the scientific justification of an image like that? There were also a whole bunch of them back during the Phoebe flyby...

Posted by: Decepticon Jan 14 2006, 10:44 PM

Some data already on the ground.

http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-list.cfm?browseLatest=0&cacheQ=0&storedQ=0

And this image, Curious as to what was attempted here?!

http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=60312

Posted by: Greg Hullender Jan 15 2006, 12:07 AM

Can we see a beta version? :-)

--Greg

Posted by: David Jan 15 2006, 04:28 AM

That's a pretty good look at the big ring crater (I've forgotten its name) and the "smile" semicircle of brightness down south.

Posted by: dilo Jan 15 2006, 01:26 PM

Very interesting, maybe they didn't correctly reduced bit depth of original image (truncating most significant bits)... this give a hint of real image dinamic range and inspired me to do something vaguely similar (solarization), now clearly showing bright clouds on other nice details...

Posted by: jmknapp Jan 15 2006, 01:51 PM

Very interesting. I applied an edge filter to further bring out the detail:

Posted by: dilo Jan 15 2006, 06:06 PM

Yes,jmknapp, veery interesting (maybe you forgot a ...).

Posted by: alan Jan 16 2006, 07:18 PM

new images are posted
http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-list.cfm?browseLatest=0&cacheQ=0&storedQ=0

Posted by: ljk4-1 Jan 16 2006, 07:34 PM

Some of those raw Titan images remind me of the Earth-based photos they took of Neptune around 1979 before the Voyager 2 flyby in 1989. The ones with the dark band between the middle.

http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=60463

http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=60462

Cannot seem to find them online, but they were the main images shown when presenting the latest info on Neptune before 1989.

Posted by: ugordan Jan 16 2006, 10:30 PM

Does someone have an idea on what a weird feature in http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=60698 image is? It's located at the top of the disk, a weird ring-looking feature. I don't know the orientation in the image, but the extended haze at 10 o'clock suggests that's the azimuth of the north pole.
The feature is visible in at least another image.

Could it be a real feature or a weird optical artifact?

Posted by: djellison Jan 16 2006, 10:37 PM

I THINK it might be real - Jason will probably smack me down for this....but is it Cloud?

On second thoughts - it does seem to simply appear and dissapear with unusual filters - maybe it IS an imaging artifact - it doesnt quite move with Titan does it? JASON!!! Help!!

A quick RGB, I love these high angle images

Doug

Posted by: ugordan Jan 16 2006, 10:40 PM

I think it's too high to be a cloud, it's way up in the haze layer. I'm going to be cautious and not dismiss light scattering by the optics just yet. The feature DOES seem to be neatly centered on the anti-solar side of Titan's disk, a little too much of a coincidence if you ask me.

That said, it does appear to be below the main boundary of the haze. Could it perhaps be a complex refraction of sunlight?

Posted by: mchan Jan 16 2006, 10:43 PM

It appears to have some symmetry to my untrained eyes. A symmetrical cloud formation?

Posted by: exoplanet Jan 17 2006, 12:51 AM

How odd . . . it appears to be perfectly round too. Also the two dots of light above are nearly the same distance apart as though they went through the doghnut shaped cloud. This has to be an artifact but if not . . .

Seems quite odd too that we see a feature like this at Titan's north polar region and then we find all sorts of activity at the south polar region of Enceladus.

Posted by: JRehling Jan 17 2006, 01:44 AM

Is that the north polar region? I can't tell what orientation we're looking at -- there aren't any clues I know of, besides possibly this ring-cloud.

If it is, note that Voyager imaged a dark ring over Titan's north pole -- in visible light and above the haze; of course, Cassini has imaged bright clouds around the south pole -- in IR and below the haze.

Overall, we have to suspect that the convection patterns at Titan are poleward at some altitude, and since the polar longitudes are smaller than the equator, this causes a "traffic jam" where air is forced up (or possibly down). That would naturally cause rings, but I'm hand-waving here -- the details are obscure.

My synthesis of this has been that the summer pole has low-altitude methane clouds that somehow (try: lightning) changes the chemistry in the vicinity even at higher altitudes. Perhaps some organics created by lightning are light enough (or dark enough, and thus warmed and rising) to climb over the haze. This ring (if not an artifact!) may be the same "smoke ring" seen by Voyager as a dark ring over the haze.

As for what happens at the winter pole, that's potentially/probably a separate question.

Maybe this ring is over the summer pole?

Posted by: Decepticon Jan 17 2006, 02:04 AM

How about a aurora?

Posted by: jmknapp Jan 17 2006, 02:07 AM

Here's what I get for the view at the time of this shot (15JAN2006 19:51UTC):



That view doesn't account for any rotation of the spacecraft, but evidently the feature is directly opposite the crescent in the Cassini image? Which would put it pretty far off the pole if so.

Posted by: dvandorn Jan 17 2006, 03:11 AM

I know, it's almost definitely an image artifact. But... it looks like a plume to me. The top of an umbrella-shaped plume from some massive vent or cryovolcanic eruption, propogating through the visible atmosphere and out into the haze layer.

What kind of energy would you have to generate to force a plume through the atmosphere and into the haze layer?

-the other Doug

Posted by: edstrick Jan 17 2006, 09:09 AM

The "Anomaly"....uhoh... I said the A-word!.....is visible in 4 or 5 frames. When I use ACDSee to step through the sequence of frames like a movie, the halo over the nightside limb seems to move relative to the limb. The two bright dots above the limb are probably stars, they move relative to Titan during the sequence.

I'm very very inclined to think this is an image artifact, but it's the oddest, most sharp-edged, real-looking scattered light or whatever artifact I've seen from these cameras. Also, it's present in some images, but not other ones with similar overexposure of the illuminated crescent that are *in the middle* of the several frame image sequence.

Conclusion: duh.. I dunno. These weren't really long exposures or the stars would have trailed like they do durnig Iapetus saturnlight images, so if it's aurora, it'd be unbelievably bright, I think.

Posted by: Sunspot Jan 17 2006, 09:43 AM

I think it looks like an Aurora too.

Here's an image of the Aurora on Saturn from Hubble

http://hubblesite.org/gallery/album/solar_system_collection/pr1998005a/

Posted by: ugordan Jan 17 2006, 09:53 AM

Well, it could still be a longish exposure, keep in mind these are wide angle camera shots. The WAC is much more sensitive than NAC is and any target motion compensation is bound to leave 10 times shorter star streaks due to the larger field of view.
I believe we can definitely rule out the aurora, as I said before the north pole is somewhere around 10 o'clock direction and not directly on top. The most plausible explanation would be unusual light scattering from the sun (which is itself out of the field of view). Were it not for the calibration lamp in the wide angle camera, there probably wouldn't be any significant scattering, but as it is the lamp and its three supporting rods likely induce diffraction patterns, depending on incoming light angles.
We might actually be seeing a distorted, reflected/refracted image of the sun through the calibration lamp's glass.

Posted by: Bill Harris Jan 17 2006, 10:34 AM

I don't think it is either, but remember that the magnetic pole does not have to coincide with the rotational pole and auroras are centered on the magnetic pole.

--Bill

Posted by: djellison Jan 17 2006, 10:41 AM

I'm going to put my vote in the hat marked "Imaging Artifact on one filter wheel"

Doug

Posted by: edstrick Jan 17 2006, 11:27 AM

Ugordan's idea isn't bad, whether it's correct or not is another question.

Regarding aurora ideas.. Titan has no global magnetic field, and little if any field that extends up into the plasma sheath around the moon. Voyager flew through Titan's magnetic wake -- a good geometry to see an internal field -- and detected only the interaction of magnetosphere plasma blowing around the moon's upper atmosphere/ionosphere. Cassini has much more data by now on the interactions.

Posted by: jmknapp Jan 17 2006, 12:19 PM

Accounting for the orientation of the camera, here's a quick-and-dirty correspondence of the image with the Titan globe:



I.e., the feature centered around 100E, 25N.

Possibly a ghost image of the main image which is itself a ring?

Another idea: a meteor?

Posted by: Decepticon Jan 17 2006, 01:38 PM

^ Maybe the trail of a meteor?

Posted by: Ames Jan 17 2006, 01:59 PM

Solarized the image and got...

Curious don't you think?

Nick

Posted by: jmknapp Jan 17 2006, 02:19 PM

BTW, this was the scheduled activity at the time of these observations:

begin: 2006JAN15 19:41 UTC
end: 2006JAN16 02:24 UTC

ISS_020TI_NIGHTNAC002_PRIME NAC Nightside Imaging: search for and monitor lightning/aurora

Posted by: odave Jan 17 2006, 02:29 PM

Hmmm - it could be an aurora - check out some of the views of Earth's aurorae from space:

http://www-istp.gsfc.nasa.gov/istp/outreach/afromspace.html
http://antwrp.gsfc.nasa.gov/apod/ap030408.html

They were taken at a much lower altitude, of course...

Posted by: djellison Jan 17 2006, 03:01 PM

Who know - perhaps it is. Earth Aurora are based around Oxygen emissions irrc, whereas Titanian Aurora would be based on what I assume must be Methane?

Doug

Posted by: belleraphon1 Jan 17 2006, 03:26 PM

I believe that the excitiation would more likely come from the nitrogen.

Be that as it may, as edstrick pointed out, CASSINI has not detected an intrinsic magnetic field for Titan. I wonder if the plasma from Saturn's magnetic field could cause something like this as it impacts the Titan atmosphere? Or is there some electric or magnetic field that gets generated as a buffer tha protects the atmosphere?

Do we have a mag person on this blog?

Craig

Posted by: djellison Jan 17 2006, 03:30 PM

Well - that's what I thought initially, given that Nitrogen is the main gas there, BUT, it's 'most' of the gas here on earth, and I was under the impression that it's mainly Oxygen and other gases, not Nitrogen that cause the earth aurora - BUT - on further reading, the red aurora on earth are indeed Nitrogen based, so one can only assume that Titan aurora would be in the same ballpark.

Doug

Posted by: Ames Jan 17 2006, 03:36 PM

And the "Artifact" is indeed evident in red in your multi spectral image (if your colour allocations are indicative of the filter colours)

Not totally convinced yet! but...

Nick

Posted by: djellison Jan 17 2006, 03:39 PM

That freakier one was indeed nIR, G, B

Doug

Posted by: ugordan Jan 17 2006, 03:39 PM

You need to be VERY careful when making statements like this about uncalibrated, stretched raw images. If the colors were correct and assuming RGB or RGV filters, Titan's dayside (at least parts that weren't overexposed) should have turned out orange in color.

Posted by: dvandorn Jan 17 2006, 06:54 PM

That looks like it supports my plume theory!

-the other Doug

Posted by: dilo Jan 18 2006, 03:51 AM

The plume/aurora hypothesis is very intriguing, but also in my opinion this is an image artifact.
In the following color image, I combined 3 pictures taken with IR3+CL2, IR2+CL2 and MT3+CL2 (RGB respectively)...

the circular features appear always in the same, exact position, while the coulored Titan edges suggest a subject movement (note also the two moving stars in the upper region); so the features appear fixed to optical system and do not follow Titan.
As further confirm, I stretched another image taken earlier and closer (C1+VIO) showing a very weak feature in the same position, but far from Titan edge!

About solarized image by Ames, this "plume" do not appear at all in another image taken with same filters but different pointing:

So, the plume is probably an artifact related to residual solar light, entering the optics and reflected/diffused under this particular geometry.
Still to be explained why this feature is evident only in infrared images, while do not appear with V/UV filters or is very weak (look to the following B3C2 image):

Posted by: djellison Jan 18 2006, 08:23 AM

Yup - I'm back in the artifact camp now

Doug

Posted by: edstrick Jan 18 2006, 08:29 AM

Just as long as the artifact isn't an orbiting semi-gloss finish coated black monolith....

That would be weirder than this whatever it is.... I think.

Stop Dave, my mind is going...

Posted by: tty Jan 18 2006, 08:23 PM

It could be a local magnetic field over a magnetic anomaly. I seem to remember that weak auroras have been observed over such areas on Mars.

tty

Posted by: jmknapp Jan 19 2006, 01:25 PM

Titan Magnetic Anomaly 1? The 2001 Moon monolith was called TMA-1, for "Tycho Magnetic Anomaly."

Posted by: Decepticon Jan 20 2006, 12:34 AM

Wow! http://saturn1.jpl.nasa.gov/multimedia/images/raw/casJPGFullS17/N00048521.jpg

Posted by: paxdan Jan 25 2006, 11:22 PM

It's a stunning picture, could someone please produce a colour version, or do the long readout times cause a registration problem?

Posted by: paxdan Jan 25 2006, 11:44 PM

for the movie the finish on the monolith was a thin graphite coating, i.e., the entire surface was drawn on by hand using a pencil. It was so laborious to create no-one was allowed to touch it as fingerprints would ruin it. The finish proved so alluring that it had to be covered when not in use to prevent people stroking it!

Posted by: ugordan Jan 26 2006, 08:04 AM

The sequence wasn't taken through multiple filters so color just isn't possible.
It'll sure make Cassini POTD, though.