Three Goldilocks planets discovered orbiting the same star. They’re all in the Goldilocks zone where water can exist in liquid form, which is supposedly necessary for life as we know it. Perhaps any kind of life. Almost certainly for any kind of advanced life, though who can be sure? So if advanced civilizations developed on one or more of those planets they would quite likely visited the other life-supporting planets in their system at an early stage of development, the stage we’re at know, and perhaps in learning about those other planets that were quite like their home planet they may have learned to look after their own planet better. Or if they did trash it, at least they’d have a Planet B to move to, and then a Planet C after that if they wanted to. Then maybe they’d be advanced enough to travel to other stars and they’d happen across us, this remote planet, like an Easter Island to their Europe, and they’d witness us doing to our planet just what they did to their Planet A. Would they intervene and stop us or would they sit back and watch us with great academic interest? Historical interest as to their historians it might be like watching their own history unfold in a parallel universe.
Gliesians. Or Gliese667Cians, to give them their full name. If other advanced civilizations developed on the other two Goldilocks planets then they may well have interacted the way the Europeans did, whilst learning from one another, competing and trading, advancing themselves. If we were being visited by aliens it could quite possibly be the Gliesians. They’d develop far more rapidly than we have, and with three planets, they’d have more chance of surviving through that awkward stage in the development of a civilization, when it comes close to destroying some aspect of its environment that it relies on. In the case of Easter Island it was their trees.