During my gameplay (10 hours into my first game, 5 stars), I've fould myself using my mouse wheel like crazy. It's sensitivity to zoom from/to the marker makes for an easy and smooth jump a'la Black & White from one planet to the other; the more distance, the more wheeling. I definately encourage getting a mouse over a touchpad (I'd say that for any game anyways ^^). But settle for zoom hotkeys and scroll screen if you'd rather avoid getting a mouse should work fine.

thanks much, everyone.  i suppose i missed the hotkeys when i was leafing through the manual.  the 'v' and 'b' keys work perfectly, and my 5 starsystem game is suddenly much more manageable.