Theories about the origin and causes of the phenomenon are numerous. I feel exactly the same way about UFOs. I believe they are very real, but they are also powerful mythical reflections of our own psyche. Our ability to accept inner divinity determines how these aliens manifest in our world. Light Travelers know that whenever there is a local agreement on reality forms manifest around it.
Spirits congregate to form clusters of meaning and new relationships for growth.
Those planets qualify as space-holding ships, or worlds of diverse beings where individuals are cultivated out of the light flow. The process appears universal and is the primary reason for physical existence. In many ways that process has been delayed by forces that choose to divert major portions of awareness energy. They have succeeded. People often fear the truth, and are held in place by a limited view of love.