CICLOPS: Cassini Imaging Central Laboratory for OPerationS

Sector 6

Show carolyn's comments posted in past:       

Visions of Saturn Danced in Our Heads
12-25-2014  07:53:20

We will be posting a larger version of Michael's glorious painting come next week, when the CICLOPS staff is back at work. Cheers!
12-25-2014  07:53:10

We will be posting a larger version of Michael's glorious painting come next week, when the CICLOPS staff is back at work. Cheers!
Ten Years Ago Today ...
07-12-2014  09:35:01

Thank you, Roy Miranda, for reminding us how astonishing and paradigm-shifting it is that we are now at Saturn ...VERY far from Earth and ever farther from Burundi! (And thank you for your kind words, too)
07-12-2014  09:34:54

Thank you, Roy Miranda, for reminding us how astonishing and paradigm-shifting it is that we are now at Saturn ...VERY far from Earth and ever farther from Burundi! (And thank you for your kind words, too)

A Very Special Day in the Life of Planet Earth
07-26-2013  09:16:19

Everyone: SO happy to see your comments and know you were as moved as I was by this event. It was indeed a new triumph for our planet and its intrepid inhabitants.

A Day to Celebrate the Pale Blue Dot
07-03-2013  14:30:19

sandrock and others: sandrock's remarks here are incorect. The Light Travel Time has already been accounted for. So go out and smile AT THE STATED TIME, shifted of course for your time zone.
A Day To Celebrate the Pale Blue Dot
06-22-2013  14:10:45

Folks: We are planning 6 weeks to process the big mosaic -- w/ Saturn, rings and Earth -- but hopefully only a few days to do the high res Earth/Moon pic. And only that if we did a good job of determining exposure times. Those pics may need a lot of processing too. Fingers crossed that all goes well!
06-22-2013  14:10:37

Folks: We are planning 6 weeks to process the big mosaic -- w/ Saturn, rings and Earth -- but hopefully only a few days to do the high res Earth/Moon pic. And only that if we did a good job of determining exposure times. Those pics may need a lot of processing too. Fingers crossed that all goes well!
06-20-2013  09:22:48

PiperPilot: I think you are confused. It's a month away! JULY 19.
A Splendor Seldom Seen
05-01-2013  10:00:12

chiptaker761: Funny you should ask this because soon after your comment we posted this image -- -- which does show stars. For bright objects in the Saturn system, exposure times are generally too short to see anything but the brightest stars. But take a look at this very long exposure of Iapetus ... ... LOTS of stars visible in this one. Lesson: solar system objects, of which you've seen lots of images, are generally bright enough and exposure times short enough that stars don't cross detection threshold.
04-14-2013  18:21:51

Thank you, dwagner and others, for the praise and kind words. We aim to serve, and continue bringing you news of this magnificent adventure. Stay with us!
The Saturn Storm Chronicles
04-21-2012  13:49:49

rem547: Patience! I'm working on an Enceladus paper as I write. I can promise: it will be fabulous and exciting and significant. Good enough for ya!?
04-11-2012  16:16:53

Je3ro: Ha! Glad you like our Golf Game. You came up with some great suggestions. Maybe we'll give those a try! Thanks.
04-11-2012  16:16:42

Je3ro: Ha! Glad you like our Golf Game. You came up with some great suggestions. Maybe we'll give those a try! Thanks.
02-06-2012  13:48:02

GorT: The ring particles are mostly water ice, w/ some very small percentage by mass of impurities, like silicates, Fe, etc.
11-20-2011  16:10:00

Everyone: There is in fact a paper about this storm that a small group of us imaging team members have written. It has just been submitted, and so now we sit and wait for the review process and hopefully publication. We can't yet answer some of your more detailed questions. But know that this discovery and the opportunity it presents will be receiving a lot of attention over the coming months and years. Scientific investigation requires a certain suite of skills and traits, and patience is one of them! In the meantime, thanks much for your appreciation of our work. I really wanted to make this release special, and I'm happy that it has been so well received. Best to all of you!

Haze Before Ice
01-24-2012  09:45:41

NeKto: Where have you been?! ;-) It IS raining methane on Titan!!
12-24-2011  13:54:41

NeKto: The atmospheric pressure at the surface of Titan is about 1.5 times what it is here on Earth. It's a very hefty atmosphere!

Dione 'Rev 158' Raw Preview #2
01-09-2012  08:47:15

NeKto: Titan's atmosphere is about 200 hundreds kilometers deep and *I think* that includes the upper (bluish) haze layers but am not sure.
01-08-2012  14:06:15

Welcome jaygee and all other new Alliance members! Hope you enjoy yourselves here. And to Nekto: The ratio of the depth of Titan's atmosphere to its radius is indeed large, because its gravity is weak compared to that of a larger body, like Earth's. Remember its surface pressure is about 50% greater than that of Earth's, which mean its atmosphere is substantial!

Holiday Treats ... from Us to You
12-24-2011  14:19:49

Robert: Yes, that is a wonder-filled realization, isn't it? That humankind has its machines in orbit around all of those planets that to the ancients were nothing more than moving lights. We've come far, haven't we?

Titan and Dione
12-22-2011  18:52:25

Sergio and company: Every time we release images to the public -- if they are special enough -- they are posted by a `fan' of mine on Facebook under Hope that helps. Enjoy!

The Saturn Storm Chronicles
11-21-2011  11:58:40

Everyone: There is in fact a paper about this storm that a small group of us imaging team members have written. It has just been submitted, and so now we sit and wait for the review process and hopefully publication. We can't yet answer some of your more detailed questions. But know that this discovery and the opportunity it presents will be receiving a lot of attention over the coming months and years. Scientific investigation requires a certain suite of skills and traits, and patience is one of them! In the meantime, thanks much for your appreciation of our work. I really wanted to make this release special, and I'm happy that it has been so well received. Best to all of you!

Enceladus 'Rev 153' Raw Preview #1
09-26-2011  14:14:53

libbydaddy: We are not JPL folks. We are under contract to NASA/JPL, but don't work for JPL. We are independent.
Golf Sector 6
08-31-2011  07:37:18

Bubo: Glad you like our game! We may in fact take some of your suggestions, which are good ones.

Anyone else wanting to leave suggestions, pls do!
07-24-2010  08:46:01

prichardgs: You and a whole lot of other people!
06-15-2010  13:37:09

Alliance members: are you liking our Golf game?! Let us know what you most enjoy about it, and any ideas you have for further improvements. If your ideas are too sophisticated, we likely won't be able to add them for lack of funds. (This is all personally financed!) But...who knows...some of them might be not too difficult and therefore possible. Enjoy!

Craters Before Haze
08-09-2011  08:15:25

NeKto: Very well said!

Beyond Southern Rhea
06-25-2011  13:13:56

IapetusMonolith: Ring is F ring. Not sure what blob is but maybe a blob!

Context for Baghdad Sulcus Mosaic
06-23-2011  10:00:56

MCpercussion: Not a chance! What powers the jets is the prodigious heat produced by tidal flexure...not sunlight and not radioactivity, which are feeble in comparison. The jets will still be there. Have faith!

The Ultimate Sacrifice
04-07-2011  12:48:15

Leena Jose: Not so. One expects an azimuthally uniform ring from any cloud of debris in orbit because of differential rotation. And if the material is collisional, then conservation of angular momentum would make it spread in radius, so long as it isn't dynamically confined.

Rhea 'Rev 143' Raw Preview #5
01-14-2011  12:03:23

raketenflugplatz: The moon in the center of the image is Dione.

Somersaulting Moon
01-12-2011  19:43:25

Mercury and lsludwig: Hyperion looks the way it does -- with surprisingly deep-looking craters -- because it is underdense and on the small side. This means that impactors do more compression than excavation and so penetrate deeper. And the impact ejector may (1) be less abundant because of that, and (2) escape the moon entirely, leaving no ejector blankets. For the full story, read this paper, under the SCIENCE section of this website:

Enceladus 'Rev 142' Raw Preview #1
12-23-2010  12:42:22

Iapetus Monolith: For the answer, read my article in December 2008 edition of Sci American. (Article can be found here: , Look under 2008 for Porco, C. "The Restless World of Enceladus", etc..)

Enceladus Rev 141 Raw Preview
12-01-2010  16:13:59

Andrew: The closest approach period was not dedicated to imaging, but to gravity measurements. Not sure there will be any hi res views of the north polar region.

Looming Enceladus
12-01-2010  11:48:02

Iapetus Monolith: Thank you very much!

Tiger Stripe Split Ends
12-01-2010  11:46:15

scalytail: I don't see the issue here. Are you saying the rest of the world uses Celcius? In any case, the Cassini mission is conducted primarily by the US and our readership is mostly US citizens. It's not perverse at all, but makes good sense.

The Tallest Peaks
11-01-2010  16:07:03

rulesfor: That's one way to put it!
Have we discovered evidence for life on Titan?
10-04-2010  11:35:04


Very good point, if you ask me. Let's see what Chris has to say about it.
06-08-2010  14:05:48

dholmes: Well, to be fair, the imaging system says nothing about the kind of chemistry that is at the heart of these inferences. This latest output was the work of others, and not mine. But I'm certainly an enthusiastic cheerleader!

Enceladus "Rev 136" Raw Preview #5
08-25-2010  15:29:14

Folks: We're not sure if it looks frosty because of frost on the surface or because we might be looking through a cloud of icy particles from the vents that are surely captured in this image. The illumination can be very complicated -- from Saturn, Sun, other moons, etc -- and until we get that all worked out, it will remain uncertain
Common Questions
07-17-2010  11:00:34

girlspace: I believe the Saturn eclipse we observed in September 2006 lasted about 12 hours. That's b/c Cassini was far away from Saturn and moving (comparatively) very slowly. We deliberately put Cassini out there to observe this event b/c we knew we'd get a phenomenal look at all the rings...and we did!
07-17-2010  10:58:29

ebp: It would take way too much energy (ie, fuel) to do anything like that & we want that fuel for a vigorous program of observation until the very end. However, I would have loved it! I would have loved to land on the north or south pole of Pan. How futuristic is that?!!
06-14-2010  15:57:58

Aishwarya: The `night side' of Saturn is illuminated by ring shine. So you see a ring pattern in silhouette against the dimly lit planet.
04-09-2009  09:42:56

Tommy: Good catch!! And it would be pretty spectacular, wouldn't it, to have it hanging over our heads at that distance?! Thanks. We'll fix it.

Daphnis Rev 134 Raw Preview
07-12-2010  19:03:51

MarkG: That would be wonderful if it did, because we predicted it should. See Porco et al, Science, 2007 at:

Enceladus Rev 131 Flyby Raw Preview
06-28-2010  18:12:21

Mercury_3488: Way to go, Andrew! Good job explaining why the sky looks bright in this image.

Dione and Ghostly Titan
06-21-2010  17:21:04

Mercury_3488: Beautifully said!

06-14-2010  16:00:08

parveson: Rendezvousing with the rings would take far more fuel than Cassini carries. And composition is the least interesting thing we could find from such a mission. Just seeing how individual ring particles interact would be enormously informative. Also, we are not crashing Cassini into Titan at the mission's end, but into Saturn.

Enceladus "Rev 131" Flyby Raw Preview #7
06-05-2010  18:17:05

Everyone: Thank you SO much for your congratulations and lovely thoughts on the Sagan Award. I am happy and moved beyond words. It is quite an honor and means the world to me...both the award and your warm wishes. Love to all of you!

Helene "Rev 127" Flyby Raw Preview #2
03-04-2010  18:27:56

Almost certainly the streak is a cosmic ray. What did you think it was...a flying fish?!!

Mimas "Rev 126" Flyby Raw Preview #1
02-26-2010  15:51:27

Wayworld: We just released some of the best images, and the result from one of the other Cassini scientific instruments, here:

02-25-2010  08:46:35

Red_dragon: Don't worry...we're all over it!

Mimas "Rev 126" Flyby Raw Preview #4
02-21-2010  08:18:52

20Tauri: This is being actively discussed on our team. It was an unexpected result, and very interesting.

02-19-2010  17:56:22

rochelimit: Sorry...imaging the boulders that make up the rings is not possible with Cassini. We never get close enough to do that.

Mimas and Calypso Rev 126 Flyby Raw Preview
02-18-2010  11:38:47

Nekto: I believe you are talking about Hyperion. And yes, that is the process at work on Hyperion and already described in print:
02-16-2010  20:09:09

Those of you who are interested to know how small satellites like Calypso come to have the shapes that they do should look at the Porco et al. (2007) paper on . (Look at the top of the list under 2007). In that paper we show that the shapes of the small sats near to the rings were likely due to accretion of ring material; for the inner most ones very close to the rings, the accretion must have occurred around a dense shard. For the outer small sats, like Calypso, within the region of the bigger moons, the formation process is less evident from their shape. But its surface shows how it has accumulated material. in any case, looks like the head of a fish (pointing to the left), doesn't it?

Prometheus "Rev 125" Flyby Raw Preview
01-28-2010  13:56:03

mic1303: The white specks are cosmic ray hits on the CCD detector...a well-known phenomenon.
01-28-2010  13:55:32

JimRinX: Picking up white fluffy stuff indeed....but not from Enceladus...from the F ring!!

Blemished by Mimas
01-22-2010  08:26:20

Red_dragon: I totally agree. They are among my favorites.

At Last ... 'Star Trek' Opens!
01-14-2010  14:18:06

stevekasian: Blasphemy!! How could you say that?! JPL had nothing to do with that movie. 'Twas I, and I alone, who was the science consultant and suggested that scene to JJ Abrams. And yes, it was awesome...I agree.
06-12-2009  12:39:58

YosemiteRob: Working the details as I write. Stay tuned ....
06-06-2009  11:20:03

Everyone: Here's an update about the Titan/Saturn/Enterprise scene. I spoke to JJ Abrams about it this past week. He says he's going to work on getting me a high-res frame of the scene. (JJ is VERY cool, and a really good guy.) I'll let you all know how this transpires as it unfolds.
06-02-2009  17:54:46

RJacobsen: You, and others who have emailed me, and me too (!) are all eager to get a copy of the Titan/Enterprise/Saturn scene. I had inquired of Paramount about it, and they said that the still has been offered as an `exclusive' to another publication, so I couldn't get it to put on our website. I will inquire again about it. I think all Alliance members should have a giant poster of that scene. We earned it!!
05-12-2009  17:48:35

Drewbot: I did in fact give an interview for the DVD but did not go into detail on the Saturn/Titan scene, since I hadn't even seen the final version yet at the time the interview was conducted. But I did get to discuss some of my favorite topics, like the `anything is possible' mindset that made the 1960s the fascinating, innovative and unsettling years that they were, and how that optimism underscored everything from the unbridled creativity we saw in the arts and music, to the painful (but hope-driven) events within the civil rights movement, to our bold and daring leap off the planet and onto the moon. And this cauldron of ideas and new signposts for the future found their way into the thinking of Stanley Kubrick (working on material from Arthur C. Clarke) in crafting 2001, and they found their way into the thinking of Gene Roddenberry in creating Star Trek.

I'll be interested to hear what people think about that interview when the DVD comes out, in the fall.
05-12-2009  12:36:14

PolishBear and others: I've already explained the `Titan above the ring plane' bit below. But one of your statements ... that Saturn should be much farther in the not correct. Whether or not it appears to be `close' or `far' would depend on your distance from Titan while `filming', *and* the focal length and field of view of your imaging device. You can take a look at the image at and the one at and you'll see that the relationship between Titan and Saturn in the movie is ok.

The Star Trek digital artists *did* get a few things right: the colors of Titan and Saturn, most of the details in the rings, etc. As I said, I was happy to be able to get something at all of our discoveries at Saturn in this very popular movie. Progress almost always proceeds slower than we would like, but this is progress.
05-09-2009  12:03:55

To all Alliance members:

As the official `science consultant' for this film, I would like to respond to the statements and criticisms made elsewhere on the web about the science of this film.

First, I was brought on to answer questions here and there, when the crew had them, but mostly to help with a particular plot/visualization dilemma as posed to me by the director, Abrams: How to hide the Enterprise when it re-enters the solar system, so that the Romulans don't know it's in the vicinity until too late.

It was my suggestion to have it come out of warp drive in the atmosphere of Titan, and rise up through the haze, submarine style, since I knew it could be made into a very dramatic scene. To my delight and astonishment, Abrams thought the idea was `brilliant' and immediately used it. I was expecting to be asked at some point how to get around the obvious problem that any respectable starship, Federation or Romulan, would have no trouble picking up the presence of an alien ship by other than visual means, but I never was. I didn't realize until seeing the final result for the first time myself only last week that they imagined it could be made invisible by the magnetic field of Saturn's rings. Of course, the rings don't have a magnetic field, and even Saturn's is not very strong -- certainly not as strong as Jupiter's -- and I would gladly have informed them of such had I known.

The diminution of the haze in Titan's uppermost atmosphere would be gradual with increasing altitude, but a sharper boundary makes for a more dramatic scene. And while we're nit-picking, there is yet another matter that's not technically right as far as we know: the upper haze would be horizontally uniform, and at some 200 km above the surface you wouldn't see the effects of convection, like the hummocky, clouds that are depicted in the movie.

Finally, in seeing intermediate stages of the Saturn scene, I noted that Titan was too far above the rings, and suggested that the special effects artists at ILM add in the drama of seeing Saturn and its rings in the background by pulling back and far above Titan, with the camera following the Enterprise as it rises. However, I was told that it was too far a camera move to execute and would take more time than they wanted to allot for this scene.

In the end, even I have to remind myself that this is a movie, and movies need to have visual as well as human drama. And not unlike spaceflight missions, they are big projects that must live within other, far more mundane constraints. It would be a great thing if sufficient will, time and resources could be brought to bear in film-making to make all representations of the world, natural or otherwise, precisely accurate. But then, that is asking the impossible: Remember, if you were physically in the Saturn system, it would be as dark as twilight on Earth. So, even putting a representation of Saturn on the screen so that we could see it with ease is already a violation.

Also, this particular movie is based on a well-established set of futuristic capabilities (warp drive, phasers, transporters, etc) that are certainly, at present, physically impossible and are likely not to be available even 200 years from now. So, we can't all joyously accept one collection of impossibilities, and complain bitterly about another.

From my point of view, it was a wonderful thing that Abrams cared enough about getting things right that he asked for the opinions of a scientist. I've encountered others in Hollywood in the past who did't feel any obligation whatsoever to honor the truth, so the heart of this particular production was exactly in the right place. And I felt gratifed, even triumphant, to see some of our spectacular findings at Saturn depicted on the big screen. Remember: Stanley Kubrick put the monolith in the movie `2001' on a moon of Jupiter, instead of on the Saturnian moon Iapetus where it originally belonged, because he couldn't figure out a way to get Saturn's rings looking right. Well, we don't have *that* problem anymore, now do we?

On a different note, I have to say that I have fallen in love with this movie. The special effects have finally risen to a level of sophistication befitting the saga, there are humorous moments that made me laugh so hard I cried, and the new cast has done an outstanding job capturing the essence of each of the original, oh-so-memorable characters.

As one of the fans from way back in 60's, it warms me to know that with the success of this film, we are looking at the possibility of a new dawn in this beloved epic.

Or put another way ... Star Trek lives! And I, for one, am grateful for that.

Spring Unveils Saturn's Hexagon
01-11-2010  12:58:04

BuckRogers: The vortex is not spinning opposite to the winds. We are looking down on the northern pole. The winds, and the vortex, are all rotating in the counter-clockwise direction. And Webster's definition does not apply to the giant planets! As I said, the winds and the jet stream that forms the vortex are deep. The real perplexing attribute are the sharp angles, and no one understands that yet.
01-05-2010  19:17:31

NeKto: Why should it be so surprising that atmospheric structure is deep enoughh for the infrared instruments to see? Both VIMS (near IR) and CIRS (long wavelength IR) see banded structure at Jupiter and on Saturn. So, deep circulation features are the rule, not the exception.
01-04-2010  15:52:26

BuckRogers: Impact idea is not viable. Any object hitting Saturn that was big enough not to disintegrate would end up deep in the planet, not able to affect the outer layers. This is almost certainly a jet stream. Sorry. I appreciate your imaginative explanations, though. Asking questions about why what is is the way it is is where science begins.
12-12-2009  17:13:59

NeKto: You should read the press release under Newsroom: "It encircles Saturn at about 77 degrees north latitude and has been estimated to have a diameter wider than two Earths. The jet stream is believed to whip along the hexagon at around 100 meters per second (220 miles per hour)."

Special Holiday Raw Preview #3
12-30-2009  12:01:40

Pepper: It looks smooth because it's stealing material from the F ring and even, at times, dives into the skirts of the ring -- see as an example. At these times, it is very likely being coated in F ring dust. It's craters look quite `filled in' by material...a result of this process.

Cassini's Holiday Greetings!
12-28-2009  12:48:01

Firewoman: What does `share' mean in this case? You can certainly provide a link to it, if that's what you mean.

Special Holiday Raw Preview #2
12-28-2009  12:46:08

AaronBegley: Don't be fooled. This image was taken at an incredibly high phase angle, when the s/c was in Saturn's shadow, so things that are faint at lower phase angles look `obvious' to you in this image when in fact they are not. Also, we never got a good look at the southern hemisphere with Voyager; we even missed the tiger stripes back then. Regardless, some of the jets -- and maybe all of them -- are `intermittent' in the sense that we expect they could turn on and off on a daily timescale (where `daily' here means 1.3 Earth days). You should read my December 2008 Scientific American article on Enceladus if you're interested in this moon.
12-27-2009  14:58:45

evp: It has been calculated; it is miniscule!

Thermal Runaway Model
12-13-2009  08:16:15

mipsandbips: But there's no evidence for a massive volcanic explosion. If that were the case, you'd see craters that were partially buried. And the pattern wouldn't necessarily look like what we see. Computer models have verified that general outline you would see from a dust-initiated thermal runaway effect, and they agree beautifully with the observed pattern. Finally, a dust ring has just been found associated with Phoebe, an outer Saturnian satellite. That dust is making its way into Iapetus' orbit. So all holds together beautifully.
12-11-2009  17:13:19

rochelimit: Very clever way of looking at it. Bravo!

Dichotomies on Iapetus
12-11-2009  17:11:42

JimRinX: I LOVE it! Pls finish your story and let the rest of us read it!

Global View of Iapetus' Dichotomy
12-10-2009  17:45:20

Red_dragon: And we're not finished. Stay tuned!

Enceladus "Rev 121" Flyby Raw Preview #8
11-29-2009  07:59:56

Red_dragon: Not angry at all! Just reminding you...the best is yet to come.
11-28-2009  19:12:30

Red_dragon: First, I was the individual on the team who planned those images of the jets, so I am completely familiar with them. And second, we here at CICLOPS will make our own version of that mosaic with the *real* images.
11-28-2009  08:22:43

Red_dragon: You need to read the paper I wrote for Scientific American, December 2008 issue, on Enceladus. (It is on this page: ; look under 2008 for `The Restless World of Enceladus') Enceladus is being tidally flexed by Dione. That makes all the difference.
11-25-2009  09:10:49

Dragon: We've already accounted for the interior heat source (ie, from radioactivity arising from the rock in the interior), and it is woefully insufficient to explain the heat coming out of Enceladus. The default is tidal flexing, VERY likely enhanced by a sea or southern hemisphere ocean, plus stored heat left over from an even more intense heating episode in the past. Trying to figure out Enceladus is a big challenge!

The Persistent Hexagon
11-28-2009  09:56:13

Nekto:'s coming soon!

Enceladus Rev 121 Flyby Raw Preview
11-26-2009  07:07:59

ConeyIsland: I like the way you think! Unfortunately, it wouldn't really do any good to end the Cassini mission that way. It is not equipped to do what we need to do next on Enceladus, which is determine the way its interior is constructed and do sophisticated and precise chemical analyses of its jets, for astrobiological purposes.

So what we need is another mission back to Enceladus. Get the word out!
11-22-2009  09:20:05

ultomatt: Very proud of #1. It's been my personal goal since day 1 on this mission to capture sights like this one. So when the opportunity arises, we go for it if at all possible.
11-21-2009  15:42:54

DEChengst: Yes, that would be nice! But, Cassini can't do the sophisticated kind of astrobiologically oriented evaluation that a follow-on mission could do, if we would only FLY IT!!
11-21-2009  12:31:07

DEChengst: bribes taken! But you can throw yourself into convincing NASA that the next US flagship mission should be to ENCELADUS!

Enceladus "Rev 121" Flyby Raw Preview #2
11-25-2009  09:14:30

myanhurkan: We have proposed to NASA to extend the Cassini mission out to 2017, so that we can be there to see the seasonal changes up through Northern summer. We have yet to hear if that request will be granted.
11-24-2009  17:56:31

gaponoff: Whoa! I may have been mistaken. The night side of Enceladus may NOT be illuminated by light from Saturn. I'll have to check the geometry. BUT...the sky around Enc is the E ring. We often see it bright while the night side of Enc is darker.
11-24-2009  16:29:52

gapanoff: The `nighttime' side of Enceladus is brighter than you would expect because of reflected light from Saturn. But the space immediately surrounding Enceladus is not pitch black because it is embedded in the E ring...which is produced, incicentally, from the tiny particles coming out of its jets.
11-22-2009  09:59:23

gaponoff: No, it is reflected sunlight from Saturn.

Northern Aurora in Motion
11-25-2009  09:13:05

PeterDarmady: Very happy to hear that. I've personally never seen the Earth's aurorae myself (save a really anemic display from Anchorage, Alaska a long time ago). Maybe someday I'll go to Scotland in the winter to catch a glimpse myself.

Enceladus "Rev 121" Flyby Raw Preview #3
11-22-2009  09:22:15

FrankAU: Check out our Artroom/Enceladus for what your imagined scene might look like. Or, the artwork that accompanied my Scientific American article last December on Enceladus. We owe a lot to our space artists.

Saturn's Enceladus
11-21-2009  17:26:21

GeoChick: Just so there is no confusion....this is an artist's rendition of a view of Saturn from Enceladus, inspired by our images from Cassini.

11-21-2009  12:39:24

Dragon: Be careful what you call mountain ranges. You need to know which direction the sun is coming from to fully interpret an image of a surface like Enceladus'. In some images, especially the hi res ones, what appear to be very sharp mountain ranges are actually the edges of shadows cast into deep fractures. Getting `up' and `down' correct takes some getting used to.

Enceladus Rev 120 Flyby Raw Preview
11-20-2009  16:30:32

HenryBrooks: I believe you're asking about the degree and scale of the porosity: ie, big holes in somewhat densely packed material or lots and lots of little holes spread throughout. And the answer is that we don't know that level of detail. We just know that given a body's size, and what we know of its mass and its composition, if the density seems too low for its composition, it means it must be porous. Hope this helps. (In the future, you should post such a comment under a Phoebe or Hyperion image.)
11-07-2009  09:05:55

hank: No more images to be released from this pass. You've seen the best. We're saving ourselves for the Nov 21 flyby. Cheers!

Scene Seen in the Near-Infrared
11-20-2009  11:11:46

Red_dragon: Yeah, I love these black and white images, especially in the near infrared filters where methane absorbs the light. They are so outer-space!

Spotlight on Penelope
11-16-2009  15:24:20

20Tauri and PolishBear: The reason why Tethys is so bright is BECAUSE the phase angle is near zero. All the solid, airless bodies in the solar system, even the rings, show an increase in brightness near zero phase called `the opposition surge'. (See the opposition effect on the rings in , and ignore the `rainbow' because that's an artifact.) It's a well known observational phenomenon and has its origin in 3 different effects. One, the roughness of the surface will not produce shadows at zero phase (or thereabouts), as it would at other phase angles, because the sun is directly behind the observer: that's what zero phase means. Second, one particle or body on the surface won't cast a shadow on its neighbors at or near zero phase, either. Third, there is something called 'coherent backscatter' which is multiple light scattering that occurs between microscopic grains on a surface that is observable very close to zero phase. The opposition effect can be seen in images taken of the Apollo astronauts of their own shadows: the surface immediately surrounding the astronaut's shadow is peculiarly bright. Anyway...more than you probably bargained for, but that is why Tethys is so bright in this nearly fully illuminated geometry.

Enceladus "Rev 120" Flyby Raw Preview #3
11-05-2009  19:28:38

Dragon: We, the imaging team, have been saying for years that the plume extends thousands of kilometers above the south pole of Enceladus, and then it moves into the E ring. So that result is not new.

Sixty-Four Scenes From Saturn
11-03-2009  13:33:14

bassplyr98: Hmmmm..... send an email to and find out from him how to download it. He's one of our tech guys.
08-07-2008  10:38:33

Jay55: Thanks but I feel like I'm there already!
02-19-2007  12:22:02


That's what we first thought (that one could use short clips without copyright violation). But the Beatles' music is the most highly prized musical catalogue in existence, and apparently its owners are very litigious. So, we were advised to `lay off'. And Paul McCartney has nothing to do with this. He himself couldn't have given us permission to use his music. Michael Jackson no longer owns rights to the catalogue. He had to sell out his share to pay his legal bills. As I understand it, it mostly now belongs to Sony.
01-20-2007  11:47:16

And just what is a mong?

Rhea's Ring Shadow
09-20-2009  10:02:43

Red_dragon: Wait 'til Monday, September 21!

Pan's Lengthening Shadow
09-17-2009  11:40:15

Dragon: The bright ringlet looks different because it is in fact a bending wave, and sticks out above the ring plane. If you look closely, you'll see that the shadow takes a jog there, just like you would expect if it were cast over a vertical protrusion.

Complex Edge Waves
09-08-2009  08:00:15

Voyager6: Because the particles are highly inelastic and lose a lot of their excess energy when they collide. So wave motions will damp out eventually.
09-05-2009  09:04:55

pygar: All the bodies in the rings -- ring particles and embedded moons -- travel at the speed appropriate for their distance from Saturn. The farther from Saturn, the slower they travel. Consequently, if you were sitting on Daphnis, the particles closer to Saturn can overtake and eventually pass the moon and get ahead of it; the ones farther away from Saturn, again seen from Daphnis, pass the moon going in the opposite direction and consequently fall behind. Also, the disturbances that Daphnis generates in the trajectories of the particles take affect *after* the particles pass the moon. Put these two circumstances together and you find that the particles on the inside track (closer to Saturn) exhibit disturbed motion ahead of the moon, and those on the outside track (farther from Saturn) show disturbed motion behind the moon. And that's what we see in the waves generated by Daphnis on the inside and outside edges of the Keeler gap.

Equinox Arrives!
08-24-2009  08:17:25

PeterDarmady: There are tens of millions of us here in America who feel *exactly* the same way. We just hope the government follows suit. And to everyone: stay tuned! We'll have some very exciting results for you soon.

Towering Edge Waves Pop Into View
06-12-2009  07:41:31

Everyone: The waves are asymmetric, from one side of Daphnis to another, because of the fact that the particles passing Daphnis on the inside of the gap, towards Saturn, are going faster than Daphnis, and the ones on the outside, towards the outside of the rings, are going more slowly. So, the ones on the inside have already passed Daphnis and have gotten a kick. And the ones on the outside have just been passed by Daphnis and have gotten a kick.

And we didn't know to expect anything like this until we found that Daphnis is on an inclined orbit. Still, it wasn't clear how high these things would get. All told, it's a pretty fantastic result and we are all awestruck.

Can't wait to see what we'll see in the next 2 months!

Glorious View
05-15-2009  14:21:51

Red_dragon: I quite agree!

Nested Rings
04-19-2009  20:31:33

Jay55: Well let's see what it looks like come mid-August!

In Celebration of Galileo
04-06-2009  12:24:15

Everyone: Many thanks for your kind words of appreciation for what we do here at CICLOPS and across the Imaging Team. Needless to say, it is our great pleasure to serve the world this feast of wondrous sights and discoveries, and I am very pleased that so many of you have made a point of joining us on this great adventure. You are right: Galileo would be amazed!

Stormy Pole
01-11-2009  09:59:15

The best hypothesis for the hexagon is that it is a planetary-scale wave of some kind. One of the imaging team members is busy working out a theory for it. Stay tuned!

Uranus' largest moon Oberon
12-29-2008  09:37:52

Folks: You don't need to go to the photojournal for images of other outer solar system bodies. We have brought all the Voyager, Galileo and New Horizons images over to CICLOPS. This Oberon image can be found at:

Many Faces of the C Ring
12-26-2008  10:23:32

NekTo: The other forces you have mentioned besides gravity -- solar wind, electromagnetic forces, electrostatics -- strongly affect only the smallest particles. Most of what you see in an image such as this is light reflected from the bigger particles, for which these forces have virtually no effect. The vastly dominant force sculpting the structures seen in this view is gravity.

Propeller Swarm
11-16-2008  15:18:57

Harry: The IAU has not tackled this one yet. The ink on the matter of planet/dwarf-planet has not yet dried, so I don't seriously expect this moonlet issue to arise for their consideration any time soon.
11-08-2008  09:49:13

The very fine grainy texture is indeed noise. We don't get close enough to the rings to resolve the boulders, the largest being about the size of large houses. But you can see, in this image, propeller-like features created by small moonlets, about a few hundred meters in size. We don't see those moonlets, but we can see the much larger propeller like features they create in the rings.

Enceladus Rev 91 Flyby - Skeet Shoot #8
11-08-2008  09:51:56

Everyone: I have recently written an article in Scientific American on Enceladus, where I draw together the ideas and information we currently have about how Enceladus' interior may be constructed. It is in the December issue, which should be out on the streets any day now. Let me know what you think!

Enceladus "Rev 91" Flyby Raw Preview #2
11-01-2008  09:10:53

Hello Everyone! A batch of fantastic images came down over the night, and we're right now processing them and should be posting nice, cleaned up versions later today. But I can say that it looks like everything went very well with our latest maneuver, and we're making target identifications as I write. Our next flyby of Enceladus, as you may know, is not for another year. And the sun is disappearing from the south pole with time, so that by next year we will have a far dimmer view of a shrinking portion of the tiger stripe region. So, take your fill of this fabulous place now, because it will be a very very long time before you see it like this again. Stay tuned for more!

Saturn in Recline
10-29-2008  20:22:23

You bet!

More Ring Arcs for Saturn
09-20-2008  03:44:16

Red_dragon: The origins of all ring arcs are similar in that to get longitudinal confinement to make an arc requires a particular type of resonance. In the case of Methone and Anthe, it is resonances from Mimas that confine the two moons. The particles in the arcs, which almost certainly come from the moons, are therefore also confined by Mimas. In the case of Neptune's arcs, resonances from Galatea confine them longitudinally and radially. We never saw moons like Methone and Anthe within the Neptune arcs, but then Voyager didn't have the capability to see such tiny moons directly.

Keep It Rolling
09-02-2008  08:16:23

Red_dragon: Yes, that's right. Returning a video stream would take either a lot of power and a very large antenna on the spacecraft, or more sophisticated compression schemes for compressing the images than we currently have. This is one of the big challenges in mission design for outer solar system missions: how to downlink all the necessary information.
08-28-2008  15:14:43

rulesfor: To make a color image requires that we return at least 3 images in different spectral regions....generally, red, green and blue...of the same scene. Of course, that would mean 3x as many images, and there are limitations to how much data we can return from Saturn. So, if color is not necessary for the science objective being addressed -- for example, in that image of Prometheus pulling on the F ring -- then we merely return one clear-filter image and color is not possible. Only sometimes, do we actually take color images just to take a beautiful image. Those go by a number of names, including Kodak Moments or Photo Ops. Our big Jupiter mosaic was one such image product. But mostly, we take images in different spectral bands for scientific purposes. And when we do, we can then construct a color image.

It is my dream that someday, we'll be able to send spacecraft to the planets equipped with video cameras and the best imaging devices for the express purpose of returning streaming color video of all the beautiful and fantastic sights there are to be seen out there. But we're not there yet!

Targeting the Jet Sources
08-23-2008  09:40:46

Red_dragon: If the moon has some internal strength, it might survive the tidal forces within the Roche Zone. It doesn't matter how it got in the Roche Zone ... the answer is the same.
08-22-2008  10:32:25

Everyone: Here are some answers to your questions:

Jay55: We are coming into northern hemisphere vernal equinox soon, followed by northern spring/summer. So the southern polar region is going more and more into darkness. The phase angle will generally be around 90 degrees if we're looking down on the region from above, and we also have to contend with shadows. So things aren't going to get better but worse as time in this mission goes on. But we've already gotten some good views into the fractures where the sources are, and as we've said: if the jets that are active now are leaving any effects on the surface, they are subtle, and probably because the effects we do see are cumulative. We're still working on this issue.

NekTo: Tidal heating will mostly be concentrated in the polar regions to begin with. So your question devolves to: Why the southern polar region only? The degree of internal heating you can get from tidal stresses depends on the material properties. If something flexes easily, the tidal stresses can generate heat; if it is resistant to flexing, then the stresses won't produce much if any heat. The fact that Enceladus' south pole is where all the action is tells us that the material properties within the moon are not axially symmetric, and the volume under the south polar terrain is where the tidal strain is concentrated. Many of us are busy trying to understand why! And we don't really know how close any purported bodies of liquid are relative to the surface. Some ideas for the generation of the jets suggest that they may not derive from liquid at all. However, whether that is correct or not, there is still good reason to believe there is liquid somewhere within Enceladus because otherwise, you have a very difficult time getting enough tidal heating to generate the heat we see. So, it's back to the issue above: if there is, say, a sea of liquid water beneath the south pole, then that would yield more flexure and more heating there.

Pipipot: The magnetic field of Saturn has no effect on the geology or interior state of Enceladus. However, you might be thinking of the magnetic field observations by the Galileo spacecraft at Europa, which gave clear evidence of a salty ocean within that moon. There, the imposed magnetic field of Jupiter across Europa created what we call an induced field in the ocean, and that effect was measured by the Galileo magnetometer. There's almost no chance of that happening on Enceladus, since any ocean would be smaller (since Enceladus is smaller) and Saturn's magnetic field does not rock back and forth at Enceladus like Jupiter's does at Europa...a condition that greatly aided the detection of Europa's ocean's induced field.

TomMadigan: A body straying within the Roche zone might survive being pulled apart by tides if it had some internal strength, as most moons do. There are several moons within the Roche Zone of Neptune, for example, about the size of Prometheus and Pandora, and they are apparently doing just fine.
08-16-2008  14:23:16

NeKto: That is indeed the big question, and the whole point of taking these images. But we don't have an answer for you yet. The problem may be that we don't yet know how to unequivocally recognize the effects of the process that produces the jets. For example: What geological landforms should we be looking for? Could the process be so violent in its early stages that it throws blocks all over the place, or are the blocks created by tectonics and erosion? We have some analogies we're working with, and there is a lot of discussion across the team about this right now. But it will be a while before we come to any conclusions, or even any satisfactory hypotheses that most of us think stand a chance of being correct.

No one said this would be easy, you know!
08-15-2008  17:07:37

Alliance Members: I have been very gratified that over the time that our CICLOPS Alliance Members' comment sections have been alive, there have been no `flame wars' of any kind or any of that childish behavior on our site. So far, the commentary has all been high-minded, the questions have been intelligent, provocative and educational, and it's been a pleasure to logon in the morning and see what all of you have been doing, thinking, questioning, etc. I VERY MUCH want to keep it that way.

So, absolutely keep any insults to yourself. And other than space exploration politics, please keep any such sensitive political commentary out of these pages. I will take it upon myself to delete such non-sense should it start to appear.

Remember: we are all outrageously fortunate to be able to live through this moment in time, when we can actually see things that no human has ever seen before. Just think: someday, we will have seen it all. But that's not true right now. We still have great adventures ahead of us. And I think if we all focussed on the significance of that, you wouldn't feel the need to even waste your time thinking bad thoughts. There are too many good thoughts to occupy us for a long time!

So, be good.

I'll answer some of the questions you have when things have quieted down a bit. As I understand it, our findings at Enceladus this past week are going to make it to the New York Times tomorrow. For us scientists, that's a BIG deal.


Skeet Shooting Enceladus
08-14-2008  20:29:18

demmith: We flew by the equator at an altitude of 50 km so that we could fly near the south polar region at altitudes of ~ 1400 km or so. Remember, we're not in orbit around Enceladus, but only flying by.
08-14-2008  08:32:38

3488 (Andrew): We will be using the skeet shoot maneuver for the flyby on October 31 which is also dedicated to surface imaging and thermal measurements. I'm sure we'll use it more, but realize it took a LOT of work on the part of our imaging team associate, Paul Helfenstein, to make this work. I don't know if the poor guy can live through many more of these!

We're discussing now on the team the origins of all the details, including the ice boulders. You'll need to give us some time. This is the first time we've seen these things, too ;-) !!

And when the timeline is so jam packed with exciting things to do, I doubt we would decide to put such precious resources doing the same over the north pole. Enceladus is asymmetric: that is the real underlying message here, and we know that already. And there's a lot of activity among Cassini folks, and the planetary science community in general, to try to understand why.
08-14-2008  00:24:55

Everyone: Well, was that exciting enough for you all?!! I can hardly believe it myself. Part of me during these events is overcome with excitement, and another part falls into a stupor...unable to get my head around the historic nature of it all. I mean, we here on Earth commanded something to happen clear across the solar system, and as a result of that, some precious bundles of electromagnetic radiation came screaming to us, all the way from Saturn, got intercepted by some giant antennas across the globe, were reconstructed into 2-dimensional imagery, and eventually landed on all our computer screens where all of us, across the whole planet, at the same time, saw a place we'd never seen before in such detail. Really... dwell on that for a while, and tell me how it makes you feel. It makes me feel VERY, VERY BIG. And very proud to be a highly evolved organism on planet Earth. That's not a bad calling card, is it?

About what we are seeing in our images ... we have a press release coming out sometime tomorrow or the next day...depending on how quickly the approval process moves. I think you'll like it! ;-)

Enceladus Rev 80 Flyby Skeet Shoot #3
08-14-2008  13:57:43

rgedaly: Yes, what you describe -- high density mass anomaly going to the equator, lower density anomaly to the pole -- is called true polar wander, and we suspect it could very well have happened on Enceladus. But of course, we don't know that with any great degree of confidence yet, and won't until we find out more ... about what causes the anomalous heat, the jetting activity, whether there's liquid water beneath the pole, and a million etc's after that.

Enceladus Rev 80 Flyby
08-11-2008  13:31:20

Frankypouh: Not likely. The plumes are extremely tenuous, and can really be seen well only in a very special geometry that highlights tiny particles. The jets haven't been noticeable in images of the surface we've taken before, and chances are excellent it will be the same in the forthcoming images. So, I'm certainly not expecting to be able to distinguish plume particles against the bright icy backdrop of the surface of Enceladus.
08-08-2008  15:57:22

rgedaly: The simple answer is No. If there had been a collision in the north polar region that had sufficient impact to fracture the south polar region, it surely would have left a mark. And you can see from , which is the highest resolution view we have of the north pole of Enceladus, that there is nary a big basin to be found.

Good idea though, but no cigar.
08-07-2008  16:50:33

siw0n0: The most interesting molecules found by Cassini have been detected by the INMS (mass spectrometer) instrument and these are methane (CH4) at a level of ~ 1.6%, and more complex organics (containing carbon and hydrogen) such as C2H2 (acetylene) and hydrogen cyanide (HCN) at levels about a tenth to one percent, and then a host of others in much smaller abundances, like C2H6 (ethane), H2CO (formaldehyde), propane (C3H8), and benzene (C6H6). The Cassini INMS can't measure things much heavier than benzene. Proteins and enormously complicated structures like DNA are not at all within the measurement capabilities of Cassini. So, if there are fish there, Cassini won't be able to detect evidence of them. However, it may be possible for a follow-on mission to carry devices capable of testing for the existence of the simplest chemical signatures of life. This is only one of the many reasons the next mission to the outer solar system must go back to the Saturn System, and check out Titan *and* Enceladus.
08-07-2008  15:29:05

Folks: For a nice visual graphic for the concept of `gravity assist', which is related to the answer to the question `Hoe does Cassini avoid being sucked into the gravity of Enceladus', check out the `gravity assist' movie on the following site: . This shows the passage of Voyager by Jupiter during the Voyager flyby encounter in 1979. The gravity of Jupiter is one helluva lot more than that of tiny Enceladus, and yet Voyager avoided being sucked into Jupiter. All because it had sufficient speed. Instead of being sucked into Jupiter, its path was altered by Jupiter significantly. So it is with flybys of Cassini by the moons around Saturn. Titan, being the biggest body, alters the speed and direction of Cassini so that we use Titan for doing most of the maneuvering around the system, using the on-board fuel for smaller tweaks. But even passage by smaller moons can affect the spacecraft's trajectory a bit. We do `clean up' maneuvers with the spacecraft fuel after these events to put the spacecraft back on its track.
08-07-2008  10:01:32

So here we go. This flyby could be the best of them all for imaging scientists who are hoping to peer deep into the fractures at the surface sources of the jets. Estimates of the tidal stresses across the south polar region indicate that over the course of an Enceladus' orbit, the vents could open by as much as 1/2 meter. We won't see such openings even in our highest resolution images, but maybe ... just maybe ... we might see other evidence of eruption, either something geologically unusual or banks of snow where icy particles in the jets fall back to the ground. Whatever we see, this will definitely be a first and very unusual event. As I said long ago (it seems), as we were first entering the Saturn system, and about to begin our explorations: Prepare to be amazed!

Cassini Favorite Image Contest
08-10-2008  10:55:14

Lillyreyes: It pleases me no end that our work moves you to want to tell the world, especially your students. Encourage them to visit our CICLOPS website and enjoy!
07-11-2008  16:20:14

Indigo: The picture you refer to is not a real image. It is a synthetic image made from the data collected by the Radio Occultation (RSS) experiment. They collect the signal from the spacecraft as it passes behind the rings. This gives a single slice through the rings, which they then use to create a fake image. This is easy to do once you know/choose a geometry from which to look at the rings. And phony images don't count!
01-10-2008  14:23:51

Nvoelz: We scientists never knew there was a blue part of Saturn, either! It took us by surpise too. And it's hard to argue with your choices. They too are true gems. Really....can you think of a more beautiful place than Saturn?

Map of Tethys - June 2008
08-10-2008  09:33:28

You think this is boring? What about Mimas?!!! It's a good thing there's Herschel crater or there would be no drama at all on Mimas. Now, as a member of a collection of bodies, it and the other `boring' moons provide valuable points of comparison in their mass densities, compositions, cratering records, etc, so they really aren't as boring as they look. In fact, they are quite valuable and we're glad to have the opportunity to explore them. But for exquisite geological formations and that instinctive `I wanna go there' emotion they evoke, it's hard to beat Enceladus, Titan, Iapetus, and even Dione.

Saturn's Subtle Spectrum
08-03-2008  07:54:28

Rulesfor: We will be selling hard copy prints of Cassini images. Go to Store at and mail your suggestion for the image. Include the PIA number and any other relevant description. We're not completely set up yet, and can't do bulk orders, but could do a limited number. Also, join our Forum to discuss issues related to science and the media.

Sixty for Saturn
07-15-2008  14:15:10

Welcome, smstowm! Glad to see you've joined the Alliance, and hope you enjoy visiting. Be sure to tell your friends about us too.

Odysseus the Great
07-12-2008  09:59:32

Bruno: I look at the cloud structures in the Saturn atmosphere and think of strands of DNA. To each his/her own. About Odysseus and Ithaca Chasm, yes there have been suggestions that the two are related.

Contest Poster Winners
07-11-2008  11:26:54

Indigo: The image you refer to is not a real image. It is a simulated image made from the data returned by the radio occultation (RSS) experiment. They only gather information from a slice through the rings and then they turn that into a simulated image of the full rings. Phony images don't count!
01-09-2008  13:59:54

Sustayne: Great ideas! We'll take them under consideration. - Carolyn

The Ringsmith
05-29-2008  20:35:31

In order to understand phenomena like this, you must always remember that the dominant gravitational `perturber' in the system is Saturn. So Saturn's influence dominates over Prometheus' influence on the ring particles until Prometheus is practically on top of the ring particles. This is why you can get such counter-intuitive effects like a moon, like Pan or Daphnis, keeping a gap *open* instead of attracting all the nearby ring material onto itself. Also remember that the material in the F ring is orbiting slower than Prometheus. So once Prometheus makes a disturbance in the ring material, those particles that have been perturbed will travel slower and fall behind Prometheus. We have a nice movie posted on the CICLOPS site that follows the motion of Prometheus and shows how it affects the ring material only when, in its eccentric orbit, it comes close to the ring material. It is at . Enjoy!

Map of Dione - May 2008
05-22-2008  07:38:00

Andrew...Enceladus is out already, as our press release says.

Saturn's Watch Spiral
05-13-2008  14:11:58

It could be that averaged over the entire Universe, which was of course very small at the very beginning, there is no spin. Spin may just be a result of the statistical fluctuations in the motions of bits of matter relative to each other. But I am not that fluent in the work of Hawking to state what he has to say on this matter. The above is just my own conjecture.
05-11-2008  15:54:27

Most cosmic entities -- like the giant clouds of gas that galaxies formed from or the molecular clouds that stellar systems (and their planets) form from -- start with some amount of spin. The gravitational contraction process makes them spin even faster, in a similar manner to the way an ice skater will spin faster if she brings her arms in closer to her body.
05-06-2008  13:37:05

The physics is almost identical. The big difference is that in a spiral galaxy, the mass is distributed more or less evenly across the disk, making for a spiral arm with a big wavelength (ie, big separation from one winding to the other). In Saturn's rings, the vast bulk of the mass in the dynamical system is in the planet itself, with very little mass in the disk, and this makes for a much tighter winding.

This is why we can learn about disk systems throughout the cosmos -- regardless of size -- by studying the processes ongoing in Saturn's rings.
05-05-2008  09:42:02

alwolfe: We are presently writing a paper cataloguing all the resonances which are visible in our images. It will be a while before we finish it and get it published.

Coming to Light
04-16-2008  08:28:39

And you know what? We will give you more! Stay tuned for a lot of it.
04-16-2008  04:51:28

Yes! We have been given at least another two years of exploits around Saturn to continue our mission ... our reward for a phenomenally successful exploratory expedition. Our `Supreme Explorer' lives on! Needless to say, we are pleased.
02-26-2008  14:58:11

Andrew and Gort,

First, there has been no official approval of even the first extended mission...out to the summer of 2010...though it is a near certainty. Regarding the 2nd extension, it is only in the preliminary stages of discussion...a mere glimmer in the eye, so to speak. The Cassini Project believes that a very worthy and scientifically justifiable goal is the northern summer solstice, which would be about 2017. Then we will have been at Saturn for nearly half a Saturn year, with the opportunity to monitor seasonal changes in the atmospheres of Saturn and Titan, surface changes on Titan (especially the lakes in the polar regions), geysering activity on Enceladus, dynamics in the rings, etc. But we haven't even yet proposed this officially to NASA.

And regarding the plutonium/hydrogen issue, I fail to see the connection. Why would a radioactive source pose any danger for a hydrogen atmosphere?
02-17-2008  10:27:42

The orbit I describe would be highly inclined (and so therefore more or less `polar'). It is in fact being called Juno-like. And I can assure you: you will see many more encounters with Titan and Enceladus ... probably the two moons that would win in the contest for Most Captivating!

And good for you ... that you showed them all what you could do. Congratulations! And we're very glad to have you be a member of our Alliance.
02-17-2008  09:47:15

3488 (...interesting name, that), We are definitely considering a scientifically useful end to Cassini. At the moment, the ending that seems to have the most enthusiastic support is one that puts Cassini on a trajectory that takes it interior to the D ring for several (or even many) orbits before being sent into Saturn's atmosphere. This will benefit the measurement of Saturn's gravity field, as well as give us wonderful opportunities to image the rings at high resolution. And it would require too much Delta V to put Cassini in an orbit around Titan. We do, after all, want this mission to last until Northern Summer Solstice!
02-14-2008  17:12:01

Iapetus requires a lot of energy to reach, and crashing into Iapetus is not being considered for an end of life scenario.

Chances are good we will put the s/c into Saturn but this has yet to be decided.
02-10-2008  10:10:35

We have planned an extended mission, with lots of imaging sequences, to go out to the middle of 2010, and the equinox period is a special one ... both for seasonal effects on Titan and solar illumination effects on the rings. And we are now talking about a further extension to Cassini, possibly to the Northern summer solstice in 2017. But we'll see if any of this gets official approval ...

Jet Spots in Tiger Stripes
04-04-2008  15:18:44

Yes, it can distinguish between molecules of different mass. How well it does at measuring the abundance of any molecule depends on how much of the molecule is present. See Chris McKay's comment about this in a diff't earlier thread.
04-04-2008  12:59:05

Tiger: This is not the way it works. The INMS instrument measures the mass of the molecules it collects. It can distinguish between molecules that contain one or two carbons by determining that one is heavier than the other. There is no `processing' of two carbons to make a single molecule. Nature does that!
03-27-2008  18:34:32

Harry....of course we are modeling such things. We want to figure out if it's possible, with all the evidence in hand, to determine the likelihood that we have liquid water beneath the surface somewhere. The resolution of the IR is much poorer than the resolution of the imaging data. So we don't know how wide really the hottest temps, along the tiger stripe fractures, are. If we assume the region that is hot is very narrow, you get hotter temps than if you assume it is wider. And heat conduction would make the warm temps spread out horizontally. But the heat coming from below would also be carried by the diffusion of vapor (which carries heat) upward.

Interesting, huh?

Solar System in Miniature
04-04-2008  08:21:33

Welcome Tiger. But please put all you comments in one comment field. And don't worry about misspellings. We are very forgiving, and ask you to be also.

Have fun!

Enceladus Plume Neutral Mass Spectrum
03-31-2008  09:11:15

So far all we know is that there are compounds that are heavier than methane. These are likely compounds with two carbons -- like acetylene -- and maybe even three and four carbons. It's not clear to me that the INMS instrument can distinguish, however, ethane (C2H6) from other C2 compounds. Hopefully, someone who really knows the answer to this -- Chris M? -- will chime in here.
03-30-2008  17:29:34

Alliance members: Our newest member, in the event that you didn't recognize him, is none other than Chris McKay, distinguished planetary scientist and pre-eminent astrobiologist. He knows of what he speaks, and we're lucky to have him commenting on these pages. Thanks, Chris. Anytime you're moved to visit and comment, please do so!
03-26-2008  14:59:58

Ed.. Very imaginative, but ... uh ... not likely. However, I've said myself we might have freeze-dried micro-organisms in the E ring!

The North Polar Region of Enceladus
03-24-2008  12:43:17

Sergio. The Latest Comments section is meant to provide a global view of all the new comments on the site. To see the complete comment, go to the individual Image Release page (by clicking on the link on the left of the Latest Comments table) and then scrolling to the bottom. That's where you can add a comment also.

If people think we should change this way of doing things, and go to a regular forum, let me know. But I once asked the Alliance members this, and those who answered said the way it was now was ok.
03-19-2008  10:33:34

Folks.....patience, patience. It will take some time to pore over all these images and address all the questions you have come up with. There are many of them!

But let me say that we have not seen any evidence for cryovolcanism on Enceladus or Dione or any of the saturnian satellites. Nothing has flowed on the surface, despite the fact that in some places, especially on Enceladus, it would seem to the untrained eye to be so. My team members who are experts in geophysics and geology tell me that all morphological features on Enceladus and
the other satellites can be explained by tectonics. Even the complete erasure of the cratering record. And on Enceladus, some alteration is explained by past heating events and, in the south, present heating. But not a shred of cryovolcanism anywhere.

So, it illustrates the power of carrying the capability to see to greater and greater detail. In Voyager images, we concluded that the smoother terrains on Enceladus, and the wispy terrain on Dione, were the result of cryovolcanism. But with the exquisite resolution offered by Cassini, we now know we were wrong.

Makes one humble.
03-14-2008  09:29:59

Harry: you are looking at the northern region of Enceladus. The southern hot zone is far away, in the other hemisphere. But it was likely that the whole of Enceladus was warmer, to some degree, in the past.

Enceladus '61EN' Flyby Raw Preview #1
03-15-2008  17:55:58

The thin lines are much more naturally explained by tectonic stresses and fractures on a relatively thin brittle upper layer of the moon's surface.
03-13-2008  22:02:00

Not to burst anyone's bubble...but really, you ain't seen nothin' yet! Wait til you see the images that we will acquire during the August 2008 flyby this summer. During that flyby, we will be taking extremely high resolution images the tune of 8 meters/pixel...of the very spots from which the jets erupt. Hopefully, we'll find out if there is anything morphologically unusual about these locales. Maybe they all have visible vents, or openings. Up til now, we haven't had the resolution on the tiger stripe fractures to hope to see vents. But maybe in August, who knows...we might get lucky.

In the meantime, the best thing to come from this last flyby is to see:

1. Does the CIRS instrument find additional hot spots where we imaging scientists have predicted they would be from the locations we measured in our images of the individual jets coming from the fractures?

2. And will the INMS instrument definitively measure simple organic compounds and also possibly ammonia in the plume vapor. This will take us even farther in our efforts to ascertain whether or not the sub-surface source regions of the jets are as astrobiologically interesting as we now think they might be.

Keep that dial exactly where it is 'cause there are big days ahead for Cassini!

Close Brush with Enceladus
03-14-2008  09:46:40

Thanks, Spin0. And while you're at it, I'd appreciate it if you'd mention specifically that the images are the work of the Cassini Imaging Team. JPL never seems to mention this.
03-14-2008  06:48:48

Spin0: Nice video, BUT... those images were taken by the Cassini Imaging Team. The official credit line should read: NASA/JPL/Space Science Institute. Can you pls correct that in your You Tube video?
03-13-2008  08:55:33

Hi Andrew,

It does indeed look so far like the flyby, at least as far as imaging is concerned, was a success. From previous more distant observations, we expect the northern hemisphere to be cratered and not to look like the south pole. And of course, we were already well aware of the softened nature of the craters.

We'll let you all know just exactly what the assessment of our new bounty is as soon as we figure it out ourselves!

Stay tuned.

03-06-2008  19:06:14

Folks: We have tried already to image the material around Rhea but didn't see anything yet. We will be trying again in the extended mission. We can't be sure what the material is until we've caught it in an image but it may be nothing more than a very diffuse dust halo. As for the source of the material...may merely be material sputtered off Rhea and into orbit around the moon, and nothing fancy like a broken up comet.
03-06-2008  10:02:42

We are not expecting to encounter particles that are dangerous to Cassini. Such particles would have to be much larger than the typical sizes (a few microns) of the particles we find around Enceladus. Also, when we are at 50 km altitude, we are nowhere near the plume but near the equator. We think we'll be completely safe.

Enceladus '61EN' Flyby Raw Preview #4
03-13-2008  16:00:40

Harry: The characteristics of the craters in this region -- very relaxed, with bowed floors -- tells us that the ice in which they were created was, or became, warm which degraded and softened the appearance of the craters. And maybe this is due to warmth in the interior sometime during the past. This was suspected even in Voyager days. But we have no evidence that the north pole is warm...certainly not as warm as the south ... so it is not likely at all that there is liquid water within the near sub-surface of the two craters you refer to. And not likely that there would be geysers streaming out of them.

But good thinking! It's fun to see what all of you are thinking. Keep it up.

Chiseled Away
02-14-2008  08:39:36

We've been looking into this issue. Proteus didn't immediately come to mind because it is apparently not as irregular as Hyperion, which is dramatically so. So, we've altered the caption to make it more specific and correct. Thanks for pointing this out to us!
09-30-2007  18:01:31

No problem. Just the usual delays in examining the data, determining what we feel confident saying, coordinating this with all the various people on the Project, getting approval from all the various agencies for release of image products and press releases, and on, and on, and on. Doing science isn't like instant replay, you know! Look for something spectacular early in the week of October 8!

A World of Questions
02-10-2008  09:25:48

You can think of id=1086 as what you would see if you could see in the ultraviolet. So, if you were a bee, it might be `realistic'.

Fountains of Enceladus
01-23-2008  17:33:35

Gene: The `feathering' at the terminator that you are referring to is caused by the topography on the surface. If you saw the terminator of the moon at a similar phase angle, it would appear bumpy also, due to the mountains and valleys on the moone. There is no atmosphere, of course. - Carolyn

Cassini's Views of Titan
12-30-2007  07:43:09

One suggestion is that the volcanoes on Titan, if they truly are there, are belching methane, which is present in large supply on Titan and in order to remain in equilibrium, must be re-supplied (since it is destroyed in the upper atmosphere).
12-26-2007  12:39:21

You don't have to worry about lighting matches right now because there is no free oxygen in Titan's atmosphere. So though there is plenty of methane gas around, it could not possibly ignite. - C

Obscure Moon
12-23-2007  11:18:06

Yes, Red_dragon, I agree. The relative appearance of the north and south hemispheres in the methane filters, compared to the visible part of the spectrum, is very intriguing. The imaging team is presently studying this very effect. - Carolyn

Jupiter Ring Composite
12-15-2007  10:15:21

Stiliyan: The wavy pattern is a result of the quantization of the brightness levels. Since the camera records brightness in discrete values, the net result is that in the presence of a steep gradient ... and there is one across these images, due to the fact that the bright globe of Jupiter is not too far off the right side of the image and it scatters `stray light' into the camera ... you will see a stair-step pattern across the image. In some camera modes, this is less apparent than others. The jovian ring is so faint we were very happy to see it at all in these images. (The Jupiter flyby seems so long ago now....) - Carolyn

Flight over Iapetus
12-08-2007  17:43:26

VAE: Well, maybe if enough people wrote to their local and national TV stations and complained about the caliber of the news, and requested more news about the space program, something might happen. Mainstream media gives the public what they think the public wants to see. We need to reverse that impression! - Carolyn

Saturn and its satellites Tethys, Enceladus and Mimas
12-06-2007  19:32:00

JSC248, I completely agree with you. Voyager was magical, and there will never be another mission like it. - Carolyn

Saturn From Enceladus
11-21-2007  10:00:17

Are you saying the artwork is not digital? If it isn't, then we obviously cannot post it on our site. Maybe you should try taking a nice digital photo of each piece, and send that to us at
11-16-2007  08:18:31

Anaka: If you would like to contribute artwork to the CICLOPS gallery, pls send an email to with a digital version of your artwork. A PNG file is best, but we will take a high quality JPG also. Please include a brief caption, explaining the piece. Use the captions that are already on the CICLOPS Art Gallery as guidelines. Also, tell us the date it was created, and how you would like your name written. We do not guarantee that we will post them, but we will certainly consider them. - Carolyn

The Beauty of Her Veil
10-29-2007  10:13:32

Wrigleymj: Why would anyone be angry?!

On the Final Frontier
10-25-2007  10:32:45

Red_Dragon: This picture was one of those Photo Ops that we on the Imaging Team planned especially to create a glorious sight. As you can see, the planet is not overexposed as it is in Blinding Saturn ( ). The set of images that included the globe of the planet had to be treated differently than the rest. We're glad you like it.

Iapetus Rev 49 Flyby
09-07-2007  10:32:29

Yes, this is correct.

Tethys Flyby Raw Preview #4
07-21-2007  15:34:12

Tommy....almost certainly a cosmic ray hit on the CCD.

Odd World
07-06-2007  19:26:36

The images that DEChengst points out are of Phoebe, not Hyperion.

Northern Bands
04-29-2007  09:08:31

Kevin...the atmosphere of Titan, like Earth's, is largely molecular nitrogen. There are organic compound, the simplest being methane, which can be either gas, liquid or solid (ie, ice) on Titan. The destruction of gaseous methane high in the atmosphere creates the ubiquitous haze in the atmosphere.

Enceladus Raw Preview
04-25-2007  16:41:59

Gandalf.... the only plausible source is tidal heating, but it's not as clear-cut as that. Present-day tidal heating is insufficient, apparently. It might imply that Enceladus oscillates in its orbital eccentricity, gets tidally heated when its eccentricity is higher than it is today, and is still giving off today the heat acquired and stored during the high eccentricity part of its cycle. Complicated, you say? No one ever said this would be easy.

Mimas Showing False Colors
04-22-2007  15:10:10

Moonsister... The impact that created Herschel Crater, shown here, came very close to smashing Mimas to bits. And that is one notion for how rings came to be: a pre-existing moon that was catastrophically disrupted into a ring of debris that, through collisions, eventually settled down into a thin, quiet disk of ring particles.

The Enceladus Atlas
04-22-2007  15:08:30

Moonsister .... yes, all the mid-sized icy moons will eventually be mapped in this way. It's just a time-consuming process and will take some time.

Ghostly Fingers of Enceladus
03-29-2007  09:36:04

Red_dragon is right that the vast majority of images are taken for scientific purposes. And there is a lot of demand for the downlink to the Earth so that there generally has to be good reason to do the same image in different filters. But, the Cassini Imaging Team has taken some images especially for artistic purposes. The first one of these was the Greatest Jupiter Portrait, at Jupiter flyby. And during Cassini's tour, we have taken others ... just to capture a beautiful sight. And we will do the same during the extended mission.

03-29-2007  08:10:43

The equinox at Saturn occurs in August 2009, and there are observations planned of the rings and moon shadows during that time.

Land of Lakes?
03-29-2007  08:09:23

It is not a RADAR image that shows a possible shoreline near Titan's south pole, but an ISS image that goes back to June 2005. That was the first detection of anything lake-like on Titan, though the evidence was only morphological and that feature's association with clouds and possible precipitation/evaporation.

Io Eclipse In 'True' Color
03-24-2007  06:30:55

The images were taken by Cassini from a distance of only 10 million kilometers during the Jupiter flyby of 2000/2001. An AU is ~ 148 million kilometers.

Hello Again, Jupiter!
03-22-2007  14:48:34

Well, we don't like to talk about THOSE images!
03-19-2007  07:24:15

No. The first image we took of Saturn was in late 2002. Go take a look under the Beyond Jupiter sub-directory of Image Diary.

Giant Lake on Titan
03-15-2007  08:25:01

Planetfall .... Patience, patience. Any day now.
03-12-2007  10:12:45

Ph.... Though there was a time when Voyager first flew by Titan that it was believed there might be liquid nitrogen on the surface (and I can tell you that on that day I felt like I was in the middle of a science fiction movie), we now know the conditions aren't right for nitrogen to be liquid. However, you are right to be skeptical about liquids on the surface, because the definitive evidence -- sighting of a specular reflection -- has not been observed yet. Unfortunately, it is quite difficult to see a specular reflection at the poles, so it's not clear we'll be in the right geometry to see such a thing from the `lakes and seas' near the poles.
03-01-2007  15:53:11 all are in for a treat. There's more to come on this story, perhaps next week. Stay tuned.

The Lore of Saturn
03-04-2007  08:46:58

Red_dragon.... Yes, we agree. That's why we called it what we did.

Rough and Tumble Hyperion
03-03-2007  11:11:43

ward120 ... those are just bad pixels that were not properly removed in the making of the movie. Nothing to get too excited about!

The Great Crossing
03-01-2007  20:16:47

Moonbird (great name, by the way) ... Cassini's nominal mission ends the middle of 2008. However, chances are excellent that we will be given an extension of two more years, and we are currently planning for that. We should know with certainty really soon. After that, I would say it's likely we will be given further extensions, but it's hard to predict the funding level that far ahead. Fingers crossed for us. And be sure to let your congresspeople know that you feel Cassini is a worthy use of your taxpayer dollars.

Jupiter Mosaics and Movies - Rings, Satellites, Atmosphere
03-01-2007  18:01:00

Vista.... You won't see Phoebe again like you saw it back in 2004 because it is an outer moon of Saturn, and it was just by luck that our approach to Saturn brought us close to Phoebe. Now our orbits around Saturn are so much smaller, we never get out to Phoebe's distance again. But it was a grand opening to a spectacular show, wasn't it?
02-19-2007  12:18:20


Very imaginative idea but not likely. This is almost certainly an artifact of the processing....probably a bad pixel that got reproduced, from frame to frame, in the interpolation scheme that was used to make the atmospheric motions look smooth between the actual image frames.

The Color of Darkness
03-01-2007  15:57:32

What a great title: Night of the Million Moons. I like it. Though maybe it shoudl be Night of the Countless Moons ?

Symmetry in Shadow
03-01-2007  15:55:44

It is lovely, isn't it? You folks have good taste!

Icy Crescent
02-26-2007  08:40:22

I agree with all comments here. Crescent images -- whether they be Dione or Saturn or Titan -- convey such mystery and drama, and this one is one of our best of the icy moons. You really feel like you're flying, at low altitude, over those fresh-walled craters.

And it is remarkable how few people know that we are now exploring Saturn. So all you Alliance members: be sure to get out there and let everybody know!

Brilliant Ice Dust
02-12-2007  21:16:47

You are welcome, Dusty. And thank you for visiting our site and exploring Saturn with us. It is our pleasure.

Alien Sky
02-11-2007  17:11:16

I meant ..... a 250 x 250 JPG.
02-11-2007  17:09:06

Artwork must be submitted for approval, and be of the right size and format.

Send a digital copy of your work -- say 250 x 250 JPL -- to . Pls include a simple caption (see those already posted as examples), and your website (if you care to include that). You will hear from us, one way or the other.

Beneath Titan's Veil
01-20-2007  11:44:13

The illumination at the cloud tops of Saturn or Titan, which one could call `broad daylight' in the Saturn system, is about 1/100th of daylight on Earth and is similar to early Earth twilight or dusk. At the surface of Titan, it is akin to deep Earth twilight or dusk.