[X] My Assistant

[volcanopele]

There are a few new names for use on Phobos. These include Grildrig (Corona?) and the craters Clustril, Drunlo, Flimnap, Gulliver, Limtoc, Reldresal, and Skyresh.

Any chance of a map with these names?

[SickNick]

Regarding the "success" or "failure" of each folded map to match the *real* object - if you look at the "apple turnover" versions, the sub-cells within them are clearly highly distorted with elongate craters and enforced lineations. I would not expect these to fold-up to a good representation of the original due to this distortion. In the better versions, the fit is better and the distortion less.

Ultimately, you will exceed the limit of what is possible with 2D paper, in trying to fit the 3D surface...

[chuckclark]

Regarding the "success" or "failure" of each folded map to match the *real* object - if you look at the "apple turnover" versions, the sub-cells within them are clearly highly distorted with elongate craters and enforced lineations. I would not expect these to fold-up to a good representation of the original due to this distortion. In the better versions, the fit is better and the distortion less.

Ultimately, you will exceed the limit of what is possible with 2D paper, in trying to fit the 3D surface...

Okay. I'm a little slow to pick upon things, but what I've done -- in the case of the elongate craters -- is make an error of the cartographer (my subjective goof); I have NOT displayed an error of the cartography (an objective inability of the projection system [constant-scale natural boundaries] to accurately represent shape). I don't doubt this is also true for "enforced lineations," but I'm not sure exactly where and to what SickNick refers.

My error of cartography was in marking off the graticles filling in the outline: I failed to reduce them in scale fast enough as they moved inward from the map's constant-scale edge. Notice how crater elongation is parallel (roughly parallel) to map edge. If I'd shrunk the most inward part of the map more, this would have produced more circular (true shape) craters. Since I'm working these by longhand, old-fashioned geometry, and these objects are irregular, it becomes deucedly complicated to keep up with accurate scale in any map's middle portions. When (assuming when) this system is computerized, this error bar will tank. The only sectors of the map where conformality fails is in regions near hinge points, the points where you begin to fold adjoining lobes.

When SickNick says "I would not expect these to fold-up to a good representation of the original due to this distortion" he misses the point. These do not fold up to good representations of the original because the boundary (the map edge), relative to the object, is short. What happens inside the outline is irrelevant to the folded shape. I could have swirled the graticles beyond recognition, or -- far better! -- I could have sized them accurately to eliminate elongate craters (everywhere except very near a hinge point), but the folded object made by the map would be the same in either case.

And when SickNick says "Ultimately, you will exceed the limit of what is possible with 2D paper, in trying to fit the 3D surface...", I'm not sure that is true. A fine use of csnb maps made with short boundaries is that the resultant map is a compact shape. That is, a shape which is a desirable feature in a map. So it is highly useable as a map, especially because -- even in these imperfect examples -- shape distortion and size distortion are much, much less than that available with conventional projections. And when "trying to fit the 3D surface..." the trick is to employ a boundary set which is both well-branched and wide-spread on the object. And since these are irregular objects, and the branches (the line of interruption, where the orange unpeels) may grow as far as we like, it may be possible to make the sheet of paper exactly fit the object. At least in theory. Or so I'm told, by people whose job it is to know these things.

All I really do is unpeel oranges.