Thinking in 4D
Humans have trouble thinking beyond 2D most of the time. Some happen to have a talent for thinking in 3D, but these are exceptions rather than the rule. And a rare few can think in 3D over a timescape, which is thinking in 4D.
I believe this to be why stories, comics, shows, movies, and games always show Portals and wormholes as being in a stationary point on a planet or in a space station or something similar. We just don't think about that movement because of our relative perspective.
The thing is, that means to look stationary like that the event horizon of the portals has to be moving because the earth itself and the whole star system are moving through 3D space across a timescape. The other end is moving as well, meaning the odds of it occurring without outside influence directing such a connection is likely infinitesimally low.
What kind of power is required to control something like that? Something far beyond our own civilization's tech level.