I think it is a figment of your very imaginative mind. I do believe in the possibility of E.T.s and I suspect they have visited here. Yet there were a few things that gave it away. There may have been more, but two really popped out at me.
- Uranus is a gas giant, not a frozen waste
- Trilithium - Star Trek. :)
Pretty damn well put together though. Some impressive work. Though I have seen other works of yours so believe this is well within your capabilities.