3D shape, cartography, and geoid of Comet 67P C-G Options

[Phil Stooke]

Explorer 1 said:

"A 2D map of C-G seems like a tough order; the projection math alone..."


Don't worry! If you can put a grid on the surface (as we have seen already), you can warp that grid into any map projection you like. Mapping will be no huge problem - in fact I expect they have a rough one already (I've been playing with one myself).

Phil

[Phil Stooke]

Hi Chuck - I think it's premature. Despite the wonderful images we have of the northern hemisphere, we have practically nothing in the south (it was literally nothing until we began to get a few dark limbs silhouetted against the background coma). This time next year we'll have global imaging and a full shape model.

Phil

[chuckclark]

Hi Chuck - I think it's premature. Despite the wonderful images we have of the northern hemisphere, we have practically nothing in the south. This time next year we'll have global imaging and a full shape model.

Phil

Well, granted, but even if we have no global imaging, a constant-scale natural boundary map, made from the tentative shape model, would display graticles and topological districts in reasonably accurate proportions.

After the shape model is refined, I could adjust the map accordingly.

And as the images arrive, we'd have the mapping blank (so to speak) ready to go.

Note that the empty grid of a constant-scale natural boundary map, unlike an empty grid in a conventional projection, captures district proportions, so topological content (or at least prototopological, i.e. folding, content) is transformed to the plane.

The downside would be we'd need to make two models with incised graticles, and I'd have to do the handwork twice, but that's not such a big investment of time, is it?, in order to have an accurate mapping blank ready to accept images as they arrive. The investment of dollars to make the model twice is a consideration, too, but these days that's not much dough, either. Less than the cost of driving Atlanta to Houston.

Otherwise, in the interim, we have to endure viewing the available images in grossly distorting formats.