And a bit more... Phobos monolith https://en.m.wikipedia.org/wiki/Phobos_monolith https://en.m.wikipedia.org/wiki/Phobos_monolith Good ol Buzz, giving mentio

And a bit more... Phobos monolith https://en.m.wikipedia.org/wiki/Phobos_monolith https://en.m.wikipedia.org/wiki/Phobos_monolith Good ol Buzz, giving mention to the subject https://m.youtube.com/watch?v=bDIXvpjnRws https://m.youtube.com/watch?v=bDIXvpjnRws Also, Mars monolith https://en.m.wikipedia.org/wiki/Mars_monolith https://en.m.wikipedia.org/wiki/Mars_monolith Europa is another intriguing spaceball, with the (vague if you must) possibility of a life-supporting ocean. Edit: add mars monolith