Disengage Button

[Kamog]

One time in combat, the last remaining enemy ship was running away and had a big head start. My ship was slightly faster but it took a really long time to close within weapon range. The combat map kept expanding bigger and bigger, as seen by the view area indicated by the trapezoidal frame in the overview map getting smaller and smaller and planet in the middle getting smaller and smaller, too.

How does the game decide when to end the combat? In that particular battle, eventually my ship did catch up to fight the other ship, even though it took a really long time. What if the two ships have the same speed so they never get within weapon range, is it smart enough to know this?