hm, im thinking on a natural side, maybe dwarf planets on the Kerpier belt and/or junk between egar and juturn they have strange properies, like one has a non-spherical shape(think Haumea in real life) or one with moons (Eris in real life) also, i suggest Poosh(Juturns moon) is COVERED in ice and eve should, like the original pic, have thick clouds, i suggest they impede vision and increase air resistance(harder to get off the ground) Lastly, Change the orbits on Jebadiah so they do NOT cross, it is understandable science that planets with crossing orbits WILL collide some time in Kerbal history