OUCH! PLANETS ANGRY. PLEASE HELP!

[gwmarks]

I have a nice collection of 6 planets on turn 9. But they have all turned angry. I'm just now beginning to research troops, but that will take 5 turns or so.

Does anyone have advice for me?

Has anyone figured out just how happiness works and what affects it?

I've read the manual, but it doesn't help much. 1) I have good relations with three players; 2) no battles yet, and no losses. 3) I'm producing ships like crazy.
The manual says that each of these should increase happiness, but I've gone from happy to angry in just a few turns.