non carbon-based life forms?

do i think non carbon based life forms exsist? well from my understanding, non carbon based life forms is just a big fancy name for aliens. I think that it is highly unlikely, but i do believe it is possible. Every life form adapts to their surroundings. Maybe there are atoms on another distant planet that dont exsist on  Earth that can form a structure well enough for life, taking into account their planetary conditions. I cant say for sure what i think this non carbon based life form would be made out of, but i have an idea. I think that there is some kind of unknown element that has not been dicovered yet, that would be able to form "life".