In case anyone is interested, one of the Aboriginal Dreamtime legends is recounted at http://www.mysteriousaustralia.com/rexufo/index.html
and mention is made of cave art around the world that could show visitors from outer space.
Such legends are open to all sorts of interpretation of course but I quite like the idea of someone else being out there.

I didn't expect to be having a conversation about aliens when I signed up to join the Wildlife Forum. We are obviously a very erudite bunch of people!!