Are you sure that damage correlates with speed? When I tested this last summer I slammed at 42C against a gas giant and got only negligible damage.
I recommend trying this sometime as a fun skill test. Even the biggest planet is somewhat tricky to hit at that speed.![]()
Ninja'd by 777driver but yeah generally I find more module/hull damage on the high speed impacts.
During my "testing" (ok accidents) I also saw more damage from emergency drops than from impacting planets/stars. Not sure if that's 100% true though