It is possible for a cat to come back if it is left 30 kilometers away, but the chance of it coming back is very small.

Cats have a highly developed sense of smell. Its olfactory organ is called the olfactory mucosa, and the area exposed to the air It is three times larger than a human being. There are more than 200 million particularly sensitive olfactory cells on the olfactory mucosa. It is very sensitive to odors and can smell an extremely thin musk smell that is one part in eight million. But cats are not as good as dogs at finding their way around, so if you leave a cat 30 kilometers away, the chance of it coming back is very small.