Why has Cassini not done a high-rez mosaic of Titan? Options

[Vultur]

The trick for making an extrapolation look right would be the color, I think. Most of the closer images show enough variation in color that it would look unconvincing without it.

[djellison]

You've asked for insight into mission reasons why it hasn't been done.

You've been given them. Multiple reasons from multiple people.

You may not agree with them, but that is essentially irrelevant.

[Greg Hullender]

I am kind of curious why we don't seem to have better resolution maps of Titan by now, though. It seems (naively, perhaps) that there have been quite a few different flyby traectories by now, so I'd have expected most of the super fuzzy regions to be filled in. Or am I just not looking at the right composite?

http://photojournal.jpl.nasa.gov/jpeg/PIA11146.jpg

For example, there's a big blurry spot at 30S, 270W. And a fuzzy corridor at 120W between 0 and 30N. On the South Polar map, there's a completely blank spot at 60S, 300W. I can understand that the North has been harder to image, pending the Equinox, but why is there a blank WEDGE from 60S up between 0 and 60W?

If only to help planning for future missions, I'd think we'd want 100% coverage of the surface to some resolution.

--Greg

[volcanopele]

The southern trailing hemisphere has been poorly covered to date by Cassini. There is no getting around that. We have a non-targeted encounter, IIRC, coming up later in the XM that will help fill that gap. We are trying to fill in coverage over the leading hemisphere now. But that is mostly over the southern hemisphere, so that corridor from TA/TB at 120 W does look a bit fuzzier.

60S up between 0 and 60W - do you mean 285-315W. 0-60W looks just fine to me.

[Phil Stooke]

For what it's worth, Voyager 1 did take high resolution full disk mosaics of Titan. Voyager colour wasn't great, but it could still be fudged. So all is not lost. But you've never seen those mosaics because they are completely bland and effectively useless from a scientific point of view. Still it could be a starting point.

Phil

[nprev]

Just out of curiosity, has anybody developed a good model of the effects of phase angle & camera angle on surface resolution at various wavelengths for Titan? The haze layer seems relatively uniform; such a model might also provide some insight on its composition (not much, I admit.)

[lyford]

Ah, just film a cue ball in amber light with some vaseline on the lens and call it a day!
Or you could tweak the hue of some of MESSENGER's shots of Venus, no one will notice.*



*KIDDING.

[Greg Hullender]

60S up between 0 and 60W - do you mean 285-315W. 0-60W looks just fine to me.

Oops -- I said 60S and meant 60N!

Look at the north polar region (lower-left in the link I posted). From the pole down to 60N , there's a missing wedge between 0 and 60 W.

You can sort of see this in the rectangular map too. There's very little above 60N at all, of course, but from 0 to 90W or so, there's a lot missing between 60N and 30N.

Of course, after the equinox you'll get some great north polar pics, right? And, uh, don't forget to wrap up the south polar ones before that! :-)

--Greg

[volcanopele]

Okay, yep that gap is real. Again, in later NT encounters we should fill that gap.

Don't worry, you're not the only one who gets annoyed by these gaps. But we understand the types of encounters we need to fill them so we should fill those by the end of the mission.

[Greg Hullender]

Oh I don't think "annoyed" is the right word -- disappointed is probably closer. With so many flybys, I'd been hoping to watch the Titan map gradually fill in, but it hasn't happened that way. Glad to here there actually are plans to do it, though. I was half afraid you were going to tell me that there were some spots that just couldn't be imaged well because you couldn't have a flyby that went over them. Yet another reason to look forward to an orbiter, though.

--Greg

[stevesliva]

But perhaps some images that could be used this way will still be taken. I will be working on film until at least late 2010, so there's still time.

T-51 Titan ISS "Global Map" at 9 hours out?
http://saturn.jpl.nasa.gov/files/20090327_...description.pdf

It would seem they hope to have some cloud and haze features in there that would help mosaic-ing.

[stephenv2]

T-51 Titan ISS "Global Map" at 9 hours out?

That would rock if it is a full disk mosaic. That's what I read too - but I'm no scientist.