https://www.space.com/21337-advanced-spacecraft-propulsion-concepts-images.html
If life had started or was started on other worlds millions of years ago, then their propulsion technology would seem like magic around here.
https://arc.aiaa.org/doi/abs/10.2514/6.1998-3183
https://arc.aiaa.org/doi/abs/10.2514/3.61813?journalCode=jsr
https://www.sciencedirect.com/science/article/abs/pii/0094576587900993
https://www.science.gov/topicpages/a/advanced+propulsion+technology
Various science-fiction TV, movies and books depict what might be possible with enough advanced technological development.
There have been decades of UFO_videos and pictures.
No one is officially prepared or authorized at the UN to acknowledge that intelligent life might actually exist on many worlds and have been for a very long time.
Well, Dr. Avi Loeb is intrigued with the concept of Panspermia and the Alien_object_hypothesis.
https://lweb.cfa.harvard.edu/~loeb
https://en.wikipedia.org/wiki/Extraterrestrial:_The_First_Sign_of_Intelligent_Life_Beyond_Earth
https://www.scientificamerican.com/article/how-to-search-for-life-as-we-dont-know-it/
Of course Arthur_C._Clarke had his own fascinating take on the cruising ET concept. https://en.wikipedia.org/wiki/Rendezvous_with_Rama#Plot
https://avi-loeb.medium.com/could-uap-have-kinship-to-our-ai-systems-25c257104ca3
https://thedigitallabyrinth.blogspot.com/search?q=David+Fravor
