idk, it never happened yet, if they don’t want to keep the peace, make peace or otherwise leave us be, we’d have our first star war.
We’d be at least attacked if not invaded.
Other concerns are other lifeforms than animal, like microbial alien and so on.
It’s the first alien asteroid.
Well if the movies are any indicator, humanity is screwed if that happends
I think aliens would first invade Sweden because of higher standards of living,
More stuff to win. Who cares about Poland? Only some crazy people here.
Pffft, I’ll come for the mayonez and kielbasa!
Crazy is like a magnet to aliens, just look at all the movies when the aliens invade the USA
Always seems to be California too. 
That’s not surprising, we also have many more instances of alien abduction and probing, it’s a known fact.
We only had one famous encounter and the farmer was cool with alien sitting on his horse-drawn cart and conversating in some unknown language. There was even UFO in a rectangular shape and he was allowed to come inside. Definitely aliens treat Poland as a good place to chill out and relax. 
More detailed report: Poland's first abduction case is monumental - Openminds.tv
As to the behavior of the beings, “the subject has emphasized at several occasions that they were polite and treated him with courtesy and consideration.”
Finally!, now will you forgive us for invading?. As we the Swedish where technically aliens 
You can always come visit and relax like the real extraterrestial beings. Take them as example. 
ALL THESE WORLDS ARE YOURS - EXCEPT EUROPA. ATTEMPT NO LANDINGS THERE.
I will just drop this here…
And to further that.
Dang . . . you beat me to it Yiole. LOL.
Most detailed story I have yet to find on incident.
I remember reading in one of Daniken books about those “underwater” UFOs that had ability to rise above water and fly away. Interestingly it was before 2004. Book was rather old. These were some relations described by observers. Exactly the same type of behavior of those objects. 
I had a thought to incorporate it into EVE lore before, when DUST 514 was stil a thing. Navy ships that could descend from space into atmosphere and then underwater.
https://fightersweep.com/1460/x-files-edition/ seems to be the same incident that was reported this past week, but in a way older article.
Aliens got Trump elected.
OK, I’ll say it. Either it’s a very well crafted bonfire tale, or those seperate crews and their airplanes, radars and sensors encountered something unusual.
As for what it was: we can’t tell from a random encounter. My gut feeling, and it’s just my storyteller’s habits quicking in, is that those were human time travelers from the future.
Why? Shoddiness. Take the future where time travel is possible in certain limited conditions. SOME travelers still will be assholes, still will be shoddy, still will let “primitives” see them and their business. Just mind you, they may not come from our timeline, from OUR future.
But, aliens? No. We’re not that interesting. And probably by the time a society is advanced enough to cross the vastness of space in a sensible amount of time and meet other societies, they just figured better ways to do it.
Think of this: an isolated tribe in a secluded valley dreams of a sort of flying machines that would let them go beyond the mountain ranges enclosing their world. Yet one day, they accidentally invent radio and discover they’re in 2017 and there’s a ton of things going on outside of their valley, and they don’t need transportation devices to reach out, only communication devices.
As in, once a civilization invents the “ansible”, they discover they’re not alone but all other civilizations are so crazy away that visiting them is unfeasible… but still can talk with each other.
“Dudes, welcome the latest ansible civilization, they call themselves Human, their home they call it Earth and we’re still trying to figure where they are. They make some awesome music (for those who can appreciate music), have killed each other for nonsense endless times (hailing you the crazy ones) and have sexual reproduction, which we all know it’s the funniest”
And now I sign off before my mind starts soaring too high and this gets actual weird. 
But I think that time travel isnt possible. Well not back at least. Everything moves or stays in place in extreme cases. Its called causality. Time isnt really in the spectrum of travel, only space and speed is important. Time is an illusion, its just how our brains work, it is a frequency of sensory reception. Even atoms work with forces and speed in apcae. Time is a function we just made up. Its innate to our work because we just perceive world like that. With frequencies.
We may be in fact not interesting as much as we would think we are. From a perspective of an alien civilization greatly advanced, we would be like those other forms of life, barely capable of standing to anything outside our planet. They would only have to watch us from afar and see if we make any advances, but that would be not really interesting also, watching thru millenia how we struggle with everything.