Iapetus's (mostly) light side

[mmcirvin]

And in case you didn't see it already, here's the big Iapetus mosaic taken outbound. This is most of the section of Iapetus that wasn't imaged at passable resolution before.

I dunno, folks, the place is just damn weird.

Comments

[ronebofh.livejournal.com]

Like God sprinkled cocoa on a spherical meringue. Mmmm. Now i've got a sweet tooth...

[acw.livejournal.com]

So, what do you think it would cost to get a milliliter of that black stuff back to Earth for analysis? I'm thinking we could do it for about two bil. And I'm thinking it would totally be worth it.

What can it be? Graphite? Some weird sulfur compound? Butane ice?

(The white stuff isn't that interesting; it's fairly clearly water ice, no?)

[mmcirvin.livejournal.com]

It would actually be very hard to do that. Even a soft lander on an airless moon of one of the outer planets would probably be harder than Cassini-Huygens, because the lack of an atmosphere means you can't use it for braking purposes. A sample-return mission would need to tote along the means of getting the sample back, and just getting it out of Saturn's gravity well would be hard enough.

You can do a lot of chemical analysis with spectra, and Cassini has imaging spectrometers that can actually extract low-res images with a complete spectrum at each pixel. A lot of that was done on the flyby but it's typically a while before the spectrometer teams release results.

[paracelsvs.livejournal.com]

There... There are scratches right across the entire face of the planet.

[mmcirvin.livejournal.com]

That's actually not unique for the moons of Saturn. Those scratches reminded me of the "wisps" on Dione and Rhea, which are really systems of canyons, probably tectonic rifts of some sort. On Dione and Rhea, the canyons expose walls of bright ice and the rifts look lighter than the surrounding terrain; on Iapetus, it looks as if some of that black stuff got into them on the walls, so they look like dark streaks.

At least, that's how I'm interpreting them.

[paracelsvs.livejournal.com]

Some of the ones at the top look a whole lot like long strings of small impacts, all in a line.