[X] My Assistant

[4th rock from th...]

Here's an updated map with the lake visible on IR images. I'd like to see how this compares to the radar images ;-) but for now I'm happy that the global map is close to completion !!!

[MarsIsImportant]

100% version of north polar mosaic. The disortions are awful, but it gives overall picture.

Some of those are SEAS, not just lakes. NASA just announced the finding of seas on Titan.

http://www.jpl.nasa.gov/news/news.cfm?release=2007-026

Many of these bodies are not fully imaged yet, but their minimum sizes are larger than any of the Great Lakes. They are going to try to get better images on the next Titan pass.

[Exploitcorporati...]

Olvegg and 4th Rock, these maps are truly a public service. I can't take my eyes off of them! Lovely work, and thank you.

[volcanopele]

Some of those are SEAS, not just lakes. NASA just announced the finding of seas on Titan.

http://www.jpl.nasa.gov/news/news.cfm?release=2007-026

Many of these bodies are not fully imaged yet, but their minimum sizes are larger than any of the Great Lakes. They are going to try to get better images on the next Titan pass.

Well, there is no clear delineation between what is a "sea" and what is a "lake". After all the Dead Sea is much smaller than Lake Superior. So either is fine to be honest. Technically, all the features are lakes, no matter how big they are, but given the size of our Caspian Sea-sized feature, we like to call it a sea.

[edstrick]

I think there's at least implicetly the assumption that a lake is more or less fresh water and a sea is salty.

But we're more likely to have an agreement on a precise definition of a planet before we have a precise agreed on distinction between a lake and a sea.

And Canadians should really insist that that big epicontinental sea they have (with gobs of future post-global-warming resort properties along the southern shore) is Hudson's Sea, not Hudson's bay.

[Stu]

But we're more likely to have an agreement on a precise definition of a planet before we have a precise agreed on distinction between a lake and a sea.

We're more likely to see Elvis Presley and his co-pilot Bigfoot landing a UFO on the head of the Loch Ness Monster than we are to have an agreement on what is and what isn't a planet...

[ngunn]

Looking at Olvegg's and JTN's map overlays on the T25 thread it seems there is a distinct asymmetry in the lake distribution on either side of the north pole (even allowing for the fact that we see one side in RADAR and the other in IR). On one side it's clear that most of the surface drains into the two large lakes - maybe in fact one drains into the other, giving just a single regional drainage basin here. On the other side by contrast we see many small enclosed basins, with fewer and shorter linking channels in some cases only, indicating a lack of regional scale drainage. Given that both sides probably experience similar rainfall, I wonder what we can learn from this dichotomy? Something about the porosity, load-bearing or erosional properties of the light terrains perhaps?

I note also that near the south pole we appear to have just one largish lake (Ontario) with possibly a scatter of much smaller ones at other longitudes.

[Stu]

I've been looking a little more closely at the latest radar swath, and I'm intrigued by the terrain to the right (all mixed up with which was is north or east or whatever, sorry!) It looks very rugged indeed, and there's a distinctly circular feature there too... lake-filled impact crater? Caldera? It looks - to my untrained eye - to be on higher ground than the surrounding plain, with channels running away from it, but I might be wrong... Anyway, just wondered if anyone else had been drawn to it...

[ngunn]

We had a discussion a while back about circular and circular-ish features on Titan, of which this is a fine example. (There are others on this magnificent radar swath too.) They can be light on dark, dark on light or different variations of concentric light and dark, such as here. I agree this looks like a (low) hill with a lake inside (on top?) and stream draining out. In addition to impact and vulcanism there have been other suggestions such as sinkholes, and - my suggestion - slowly upwelling (layered?) domes eroded down to leave a cross section.

This place is just amazing. Trying to imagine the possible processes is like something between a dream and a nightmare.

[Olvegg]

I note also that near the south pole we appear to have just one largish lake (Ontario) with possibly a scatter of much smaller ones at other longitudes.

I believe Mezzoramia may be analogue of 'Caspian sea' in the south hemisphere. There are river-like features inflowing from the south on ISS images (see PIA06202 and PIA06203), and radar shows shoreline (PIA03563). It's hard to believe that such big basins could evaporate completely (or almost completely) during summer...

[Olvegg]

I updated mosaic on previous page (more detailed HiSAR swath).

[Navin]

Wow, these discoveries just continue to amaze. As a layman/lurker, thanks go to you all for satisfying my addiction to information and intelligent speculation about Titan's mysteries. I can't get enough.

Also, to the powers that be who may read this, here's my non-official plug to use my home state Minnesota as a Titanian place name. The latest comparison image superimposes the new Titan Sea right atop Minnesota, adjacent to Lake Superior. Minnesota seems to be the preferred reference point in Titan news articles.

Kudos for the great work!

[01101001]

Also, to the powers that be who may read this, here's my non-official plug to use my home state Minnesota as a Titanian place name.

I was thinking all those lakes, those hundreds of lakes, those thousands of lakes, are going to need names.

[Littlebit]

I was thinking all those lakes, those hundreds of lakes, those thousands of lakes, are going to need names.

1101001, 1101010,1101011,110111...or is the least significant lake first? (That would be me:)

[ngunn]

I believe Mezzoramia may be analogue of 'Caspian sea' in the south hemisphere. There are river-like features inflowing from the south on ISS images (see PIA06202 and PIA06203), and radar shows shoreline (PIA03563). It's hard to believe that such big basins could evaporate completely (or almost completely) during summer...

An interesting suggestion. As to the drying out: don't forget just how much methane vapour Titan's atmosphere can hold - the equivalent of 10 metres of liquid over the entire moon if I remember right. I haven't done the calculations but that might just fill a 'Caspian Sea'. I know the problem - where does the neccessary heat come from to cause the evaporation? I haven't got an answer but that doesn't mean there isn't one. My guess is that most of these lakes or seas are in fact rather shallow, so the evaporated volume may be less than you'd think just looking at them and drawing mental comparisons with large terrestrial lake analogues.