The answer is I'm doing it wrong. I know this. What I don't know is where I'm going so epic-ally wrong. I've read every thread I can find and watched every video I can and it looks like it should be easy as pie, and it just doesn't work. Have spent all day testing it to ridiculous degrees, and still nada. So, I make a system. The orbits of the two planets are deliberately set as far apart as possible. The outer planet has a moon. The moon is set to the minimum size I can (200 radius) and minimum mass (1000). The moon has 15 Haley's on it. But that didn't seem enough, so added more. And more. AND MORE! We are now up to 60 Haleys. And still the moon won't budge. When I click on 'Send to Annihilate' the following screen appears showing a max-zoomed out view of the system. From here I cannot zoom in (mouse wheel does nothing). Clicking anything on any planet does nothing, clicking anything on the icons up the top right does nothing. No action has any effect at all. I suspect the red concentric ring icons mean the planet's orbit's are too close, but I cannot spread them out any more. So - is someone able to tell me what incredibly obvious thing am I doing wrong?
The ui is just totally messed up. After you click the button, the planets all have a little red dot in that list to the right. Click that, then click anywhere on the planet.
the planet smash ui could use some work to make it more explicit. One of those low-priority issues I think.