Turn-Based movement without actual grid?

Unity Engine
1

Hi, I am new to the programing and Unity. Currently I am interesting in making very simple 4x space game like Master of Orion style. For testing and learnig porpous.

Not sure with aproach to the movement system for main star map. I can handle all movement with some (square or hexagon) grid system, but I would like to find more simple and direct solution, if exist.

Basicaly I need move from one point to another. Likely in Master of Orion you can go from one point to any other point. Only ship has range limit.

Any sugestions how to avoid making a grid system and still be able counting distance betwen points (star systems) from initial point to any other point?

Thanks

2 
public class StarRoute
{
         Planet dest;
         float distance;
}
public class Planet
{
        string name;
        List<StarRoute> connections;
      
        // all the data you want about a planet
        // ownership,  type,  etc
}

Use the list of connections to other planets to be your star routes. You can have methods to return these connections. Its a Graph of planets so it is very easy to use A* or Dijkstra to find paths for AI if you need as well