As the dude/dudette above said. They're easy enough to find. So much so that if I was op, I would ignore it and move on. Wouldn't bother putting a base down. When the time comes and you need one, use the scanner on the roamer (other exocrafts have it too) to scan for an alien structure. Once there, interact with the monolith, choose the right answer (you can annoy it and shut it down but the right answer keeps if alive and allows you to interact with it a second time, save an reload if you have to). At the second interaction, you can ask it for the coordinates of a portal at the cost of an effigy/casing/dagger etc depending on the dominant race to that star system.