The moon is 238,855 miles from the earth. So when you are talking celestial issues that is pretty darn close given the size of space which is really really really really big.
Gotta figure, the Voyager craft has made it to where it is without hitting anything large enough to destroy it or knock it off course.
Basically 40 years in a straight line flying blind without hitting anything.
Probably got some wounds from micrometeorites.