Why cant you see impact craters on Saturn and Neptune?
Saturn and Neptune are gas giants, as is Jupiter, so they do not have a solid surface, so you cannot see any craters on them. What can be seen sometimes is disruptions in the atmosphere, like that which was seen in July 2009 on Jupiter, caused by something crashing into them. As Saturn and Neptune are much farther away than Jupiter, something like that would not be seen on them from Earth without really powerful telescopes.
