Or maybe they are scouts that were sent all over the cosmos for the purpose of exploration and they will report back their findings to their home eventually.
There are plenty of rational explanations for their behavior, especially if we are extremely far behind them in our technological development.
They only have a tiny poorly manned outpost?
Are you sure you know what their goals would be?
>> Assuming they are real, the aliens do not act in a way consistent with a goal-directed intelligence, which means they are not the product of evolution, which means they are something so strange that the idea of befriending or defeating them makes no sense.
This. If - and that's a big if - we assume previous bizarre aerial activities observed by humans were in fact of ET origin, then it's only natural to think of those ETs more like AI (robots) that don't necessarily share our goal-oriented intelligence, but rather possess higher levels of intelligence and their own agenda. As a result, you're right; we wouldn't even begin to understand their purpose cause theirs just has no counterpart in humans.
Given the distances and ages required for interstellar travel, these things are more likely unmanned probes than busses filled with tourists.
> It has been theorized that a self-replicating starship utilizing relatively conventional theoretical methods of interstellar travel (i.e., no exotic faster-than-light propulsion, and speeds limited to an "average cruising speed" of 0.1c.) could spread throughout a galaxy the size of the Milky Way in as little as half a million years.
Assuming they are real, the aliens do not act in a way consistent with a goal-directed intelligence, which means they are not the product of evolution, which means they are something so strange that the idea of befriending or defeating them makes no sense. They're something more like this story: https://slatestarcodex.com/2015/04/21/universal-love-said-th...