Saturn's moons are much more likely to spread any contamination due to the presence of liquids. Liquid water on Enceldus and hydrocarbon lakes on Titan.
I assume you're just guessing, right? We already landed something on Titan! And small patches of liquid brine exists on Mars; obviously unlikely, but so is Cassini drilling through 5 miles of ice to reach to liquid water water inside Enceladus.
jessriedel|9 years ago