How Shall I Path to Thee, Let Me Count the Ways

Worked on pathfinding today. I'm a little disappointed in myself that it's taking me more than a day to implement A*, but in my defense, I was trying to be clever about it. I want the game world to be as close to Mars in size as possible. Obviously, I'm not going to be pathfinding for the whole planet at once. I plan to only simulate the area the player is focused on at any time, while approximating time passing in other areas. However, the more efficient I can make things, the larger the area I can surround the player with. For now though, I think I'm gonna strip it down and make things simple. I can complicate matters later.