It's possible, but I don't think so. It can't explain the joke. I tested it with other planets and got similar responses, e.g.:

How many D's are there in Pluto?

There's one D in "Pluto".

How many Fs are there in Mars?

There is 1 F in "Mars".

https://chatgpt.com/share/6aba6fb8-085c-83e8-9d0e-c0eed1e59c...

I guess it could think this is some kind of "give an f" joke but seems like a stretch.