As Douglas Adams observed: you might think it’s a long way to the chemist’s and back, but that’s just peanuts to space.
When I was an undergraduate I had an astronomy professor who liked to use this illustration: suppose one built a scale model of our “neighborhood” of the galaxy, using a baseball to represent the sun. If we placed that baseball on the pitcher’s mound at Busch Stadium in St. Louis, the Earth and the other bodies in our solar system could be represented by marbles, bits of gravel, etc. in the infield. (We were in St. Louis at the time).
Where would we place the baseball which represented Proxima, the next nearest star? Would it be in the outfield? In the bleachers? Across the street from the stadium?
It would be a bit farther than that. One good place to put it would be Utah.
In space, most places are no place. Most places aren’t even near a place that is near a place. And that is one is considering the confines of a galaxy, a locality where, relatively speaking, things are crowded in.
Still, there are a lot of stars out there so, for all we know, the universe might be fairly teeming with life. Maybe some of the life out there at present is intelligent. Maybe some of that intelligent life is smart enough to attempt space travel. Maybe they even have a solution for the problem that it would take years, even at the speed of light, to go from one nearby star to another.
If we grant all that–and that is an awful lot to grant–we are confronted with the problem that they would have a whole lot of other places to go exploring besides here.
BTW, what is this “planet x” talk? IIRC, this was the name given to Pluto when it was viewed as a hypothetical possibility. I have occaisionally heard the term used to refer to a possible tenth planet as well. Neither Pluto, nor a planet even further from the sun, seems a likely place to sport intelligent life. I am assuming people are using it to refer to some other idea which I am missing.
One used to hear talk of another planet possibly existing “behind” the sun, so that our view of it was always blocked. Planets move in ellipses, and they do not move at an invariable speed. It has been demonstrated that any planet which “hid” behind the sun, even if it shared the Earth’s orbit, would come up in plain view within a matter of decades.
As for the wormhole idea, it sure sounds cool, but one still has to contend the problem of the scale of the universe. First, one has to start out sort-of near the entrance to a wormhole, and then head to a place which is sort-of near the other end. The existence of wormholes is still hypothetical. In any case, if they do exist, it does not appear that our planet is near one.