I'm totally on board with panspermia, to think that we are the only life forms in the universe is the height of arrogance and it is only since the invention of the telescope that we have finally come to realise that we are nothing of any significance in the great scheme of things, and even then, the various churches insist that we actually are.
But how do we communicate with other life forms, even assuming that that have a thought process that we can relate to? Physical travel is out of the question, the distances are just too vast, so how about mind travel?
We know so little about how the universe actually works, we see the manifestations of some fundamental mechanics, you, me, the stars and so on, but are we actually anything of substance or just balls of energy and forces that give us shape and function? We really haven't got a grasp on this yet.
If it is the latter then we can start thinking in terms of communication through manipulating these forces somehow. Light, apparently, doesn't experience time, so maybe similar disturbances in the fabric of the universe can be employed to tune into the jungle beat of the universe and communication established that way.
But then, perhaps we will never be intelligent enough to do so - 'And the peace of God, which passeth all understanding', starts to make absolute sense in this regard. Is the bible telling us that we will never know?
Yet, given all the above it is obvious that there has been tremendous intelligence and knowledge on this planet long before our time. The geometry and structure of the pyramids, the exact fitting stone blocks we find scattered throughout the world, incredible structures that defy even today's engineering skills, all point to the presence of a skill set that that is well in advance of ours, but is now gone.