More on Io

[ffutures]

Working with Io again, and a VERY rough calculation which avoids trigonometry, I've got the surface area within 20 degrees of each pole as roughly 595,000 square kilometres, midway between Texas and California in size. I suppose it's just about possible to think of this as a small area compared to Io as a whole, especially if I say there's lots of geography to restrict the usable area some more. Does the size seem about right, or have I screwed up the maths?