If it is done like in the link I referred to it will reduce the brightness range between the light and dark areas while keeping most of the details. It should make the features in the dark area easier to see. I don't have the software so I don't know if it will work in this case.

Iapetus with its three impacts looms larger and larger each day:

http://saturn.jpl.nasa.gov/multimedia/imag...eiImageID=29430


Robert Schulz

nice. Looks likes the raw images page is about a day behind us. Tomorrow, there is a color sequence at 4.2 km/pixel.

My try at it..

Where did you get the tri-color data? Or did you just colorize the monochrome data?

I colorize the monochrome data.

As said before the Image is very compressed.
I would prefer a Tiff to play with.

Odd, there is very little approach images of Iapetus.


Why the wait for Raw Images?

2 Images in a week!?












Sorry Had to Vent.

It's probably just the Christmas holiday

I know.... as soon as yesterday's opnavs show up in the raw image page, I will post my color composites

I know.... as soon as yesterday's opnavs show up in the raw image page, I will post my color composites

Hmmm...when did you change your avatar??? Looks like a new image of Iapetus made it to the board already!



Eric P / MizarKey

They're up


Iapetus

Why, how did that get there? I'll post my composites shortly.

I've been seeing a faint linear feature along the equator on the raw images of Iapetus. I thought my imaginations was lining up random noise at first but this is the third day I've seen it. I wonder what it is. The large impact basin near the terminator looks like a multi-ring structure, it reminds me of Mare Orientlale.

I noticed that too, I thought at first it might be an JPEG artefact, but it looks real, it also seems to start at the same latitude as the "pimple" on the limb.

Most prominent in this image: http://saturn.jpl.nasa.gov/multimedia/imag...eiImageID=29463

VERY strange.

Wow, and this is three or four days before closest approach! What is the highest resolution imaging Cassini will attain (on this flyby)? It has been said before, but with all the changes made, I am a bit confused.

here they are

here is a time sequence

Updated middle frame

From my understanding, with C/A at ~117,500 km ISS should get about 705 m/pxl resolution in the highest-resolution imagery, which is ~10x better than the imagery acquired in October. Note that with the flyby taking place at Cassini's apoapsis, the flyby velocity is relatively slow; in fact, it would be more accurate to say that Iapetus will fly by Cassini.

So... what's going on? Is this a world-spanning ridge of giant equatorial cryovolcanoes that spew dark material onto the ice?

That would be pretty inconsistent with the age of the surface which quite frankly looks like its the oldest surface in the Saturnian system. Not saying I know what's causing the bright streaks. Could be a fault, a la Dione.

heres the fault in an earlier image look how high it is
http://saturn.jpl.nasa.gov/multimedia/imag...4/N00022208.jpg

Operating on the 'see what sticks' principle-

Could the light material be some kind of polar deposit? The non-polar distribution could be related to historical changes in Iapetan obliquity.

but then again, satellites like Tethys and Dione look ancient but do shows signs of having had tectonic activity.

Why, they must be the Death Star trench and superlaser dish!

Where is Iapetus equator in that image volcanopele?

I'm trying to get a bearing as where this is on the Voyager Global Maps.

How about this: Iapetus is hit head on by a centaur, that huge impact basin near the terminator looks like a likely spot. Some of the debris from the centaur ends up in a retrgrade orbit and lands on Iapetus's leading side.

Here is my best shot at placing a grid on these images. Not very good, I know... But I think that bulge is real..

Decepticon, I think the dark area is is centered on the equator, light areas in the latest images are on the poles.

Or maybe not Volcanopele responded while I was typing

A giant grabbed hold of it and twisted it until it cracked and the insides leaked out of it. those aren't impact basis, they are his fingerprints.

This looks similar to the crater at the top center of the dark region
http://photojournal.jpl.nasa.gov/catalog/PIA01054

Thanks!






Interesting. They do look alike.

I remember people commenting that Iapetus didn't quite round back in October. I assumed it was an optical illusion caused by the contrast beween the light and dark areas. It shows up well in this image.
http://saturn.jpl.nasa.gov/multimedia/imag...6/N00024963.jpg
How well does it line up with the anti-saturn point?

Cassini Page Update! Video Flyby.

Description of Iapetus flyby
http://www.planetary.org/news/2004/cassini..._plan_1229.html

From the Cassini website?
_____________________
Target: Iapetus - December 29, 2004
Next up for Cassini is a flyby of Saturn's icy moon Iapetus on Dec. 31. Iapetus is Saturn's two-faced moon -- one side is very bright, and the other is very dark. The spacecraft will pass about 65,600 kilometers (40,800 miles) of the frigid moon.
___________________

Has this not been updated to reflect the change in trajectory or has there been some other development that I have somehow missed?

Yes, this C/A figure is outdated. Frankly, I wouldn't be surprised if that blurb was written months ago.

Even at the current distance the Images must me Mouth Watering.

I just can't wait to see these Images!

My father says Iapetus looks like a walnut in yesterdays images.

(1) Ah. So, judging from the Planetary Society's description, radar scatterometry of Iapetus WILL be obtained during this flyby. (By the way, Jason, you never did confirm for us that Cassini missed some of its planned measurements -- including the radar -- during its recent Dione flyby, or explain what caused the problem.)

(2) It turns out that some researchers have been WAY ahead of us in noting both Iapetus' nonspherical, lumpy shape and the apparent implication that this moon has had the very devil knocked out of it at some point -- and that its whole developmental history has been radically different from that of Saturn's inner moons:
http://protostar.aas.org/publications/baas...dps2000/329.htm
http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1596.pdf
http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1660.pdf

Bruce, thanks for the excellent links!

You've got to love the internet...during the Voyager days I waited patiently for every issue of Sky & Telescope and Astronomy magazine to come out so I could see the new images and read about the exciting discoveries. Now it's a matter of hours / days before we get the information. And not just that, we get to converse with some of the people who are working with the craft / data!

My sincerest thanks to all of you who are making this happen and keeping us informed! And thanks to Doug and Bruce for the best forum on the web!

Eric P / MizarKey

I remember going to the library to scope out every newspaper I could that might, just might have Neptune coverage. Then I would keep checking Science News. Then, at last, Sky and Telescope and Astronomy would have the latest. I am still an S&T subscriber. But I think it is an old habit - I haven't taken it out of the plastic-wrap in months!

Before the Internet Space News was very hard to get your Hands on.

When it did come out it was amazing stuff.

When Voyager passed Neptune PBS did a Live broadcast from JPL.
I was so excited.

1) Not surprised considering the apparent difference in surface materials, between the Callisto-style Cassini Regio and the Rhea-style Reuxeveux Terra. I'm not certain what happened to that data. All I know is that some of the Dione data, other than ISS, was lost.
2) The non-spherical nature of Iapetus is not a new discovery, but it does provide for some annoyances.

Those were the times I still remember watching the live report from Darmstadt as Giotto flew by Halley's comet. There I was, only ten years old watching the images arrive in the middle of the night.

I remember "Neptune All Night." I was 10 in 1989, and my parents made me stop watching a little past midnight to go to bed.

I was 14 years old during the neptune flyby. Triton was a gem of a moon.


To bad this encounter is not live.

At least we have the Huygens landing. I'm looking forward to seeing the first Europa Subs with my son in the future. (I belive 100% of subsurface Oceans )

It does seem that in addition to various bumps, lumps, and seams, that Iapetus is a bit egg-shaped; but it also seems that we're still able to impose a global latitude and longitude coordinate grid upon it. How irregular does a moon or asteroid have to be before that's impossible? Could you impose the same type of grid on Phoebe? Or Hyperion?

I noticed something odd about the latest images of Iapetus: the shadows are wrong. The insides of the craters are dark on the sides closest to the poles and brighter on the sides closest to the equator when it should be the other way around. Is this caused by impacts redistrubing the light and dark material? How old would the dark material have to be to show this effect?

Mapping Coverage...



http://saturn.jpl.nasa.gov/multimedia/imag...fm?imageID=1265