No aliens exist ANYWHERE.
Aliens, fairies, unicorns, leprechauns, Jesus, time travel, gods...etc.
They're all just a word to try to explain what we can't explain, and this doesn't make them true. If I didn't understand how a waterfall worked, I'd probably say that some magic power is pushing the water off the cliff.
Does my ignorance make me correct? Absolutely not, not ever.