For this hypothetical, let’s say it’s not aliens actually visiting earth. But let’s say JWST finds a planet maybe a few hundred light years away, and we can see lights and cities and maybe spaceships or stuff like that around it. So no contact, but 100% proof there’s intelligent life out there. How would humans (and different groups of humans, like conservative Christians) react to this?
It means that they have already discovered us, and might already be on their way to destroy us. The “planet killer” was launched some 140 years ago, and it will reach Earth at approximately the year 2200.
How would humans react? Well, you have less than 180 years to build a generation ship to escape the planet before it is completely annihilated. Good luck.