When your ships bump into enemy ships, they fight until one side is dead. Admittedly, this doesn't make for easy peaceful coexistence, but this is a war game. Anyway, when you have a fight, you'll want to know what the heck happened. There are a couple of ways to find out. First, if you have " Review Battles " checked in the " Preferences... " dialog, you'll get a summary of battles at the beginning of each turn as you click through messages.
You also can select any star and review the last battle at that star by selecting " Review Battle at Proxima " (or whatever) from the " Ships " menu. If there have been two or more battles at a star, you can only see the most recent one this way.
If you lose a battle in the first round, your ship commanders don't have enough time to send you any information about the battle before they're destroyed. Thus you'll have little idea how many enemy ships are there -- just that there are enough to annihilate you.