I think, that it would be nice to include tropics, arctic and antarctic circles in planet grids. They are well defined at least for planets (the only parameter, which set their position is the angle between planet's rotation axis and it's orbital plane).
I realise, that the issue is more complicated for moons, objects with unusual orbits (without well defined orbital plane) or unusual rotation (without well defined rotation axis). That's why I propose an additional boolean parameter. It's value would decide about displaying these 4 circles. It would look like that:
- Code: Select all
(...) # all other parameters
There are two possibilities of displaying tropics, arctic and antarctic circles. They could be just parts of the grid, but they might also be displayable separately (like the terminator). They could also move in very long time scales, adjusting to eventual changes of the angle between planet's rotation axis and it's orbital plane. What do you think?
P. S. These circles should look quite funny on Uranus
"Physicists know what's important, but they don't know what is true. Mathematicians know what's true, but they don't know what is important."