Technical question: Map format

I am interested in investigating the amount of work required to create a map editor. To start my investigation, I used Space Empires V to generate a new map, and then saved it to a file (*.map).

I was hoping that a little reverse-engineering could decipher the data in the file, but when I opened it up in a binary editor, I couldn't make heads or tails of it! It seems to be either encrypted or compressed somehow.

Is there any information available on how to read/write map files, or is that just impossible at this point?