To be clear, I'm not saying the basilisk is a real concern, and I'm not saying we're anywhere close to being able to transfer consciousness. It could be a thousand years or a million years. But we don't have any basis to say it's impossible. It's not saying anything new to announce we can't do it currently. Obviously!
(Also the book "A City on Mars" by Kelly and Zach Weinersmith does a great job addressing why trying colonize Mars right now is a bad idea. Which isn't to say it's impossible or we won't ever colonize it. Just that we need more research and capabilities before doing it)