We won’t achieve ability to recognise alien intelligence until we become more aware of the makeup and limitations and specificity of our own type of consciousness. The highest (for now?) form of metarision available: self-consciousness of self-consciousness. Awareness of awareness. Analysis of analysis = meditation. First we’ll close down parts of our brain to understand reptilian and then mammalian brains. We will achieve communicative status with animals with these types of brains. Then we’ll use meditation to make the leap to other animals and plants. Only then will it ever be possible to mimic the energy patterns of consciousness aliens may present (we must attain that level of adaptability/flexibility of consciousness).
Our modes of perception and consciousness are not universal and are not in the image of God, just as most of us have now accepted that God doesn’t actually physically look like us. One tiny step away from anthropomorphism, people, not that hard.
Alien intelligence will not be manifested through remodelling of habitat, spaceships or pulses of radar signals. Goddam! That is just ridiculous. In fact such an obvious furphy you have to wonder if someone’s dangling them deliberately to distract us from the main game. It’s like expecting our TV remotes to work on their TVs or something.
Till then we will fly over apparent piles of sludge and not recognise whole civilisations.