Aliens, ancient humans or other?

http://alienexplorations.blogspot.com/1983/05/vs-visitors-with-reptilian-faces-behind.html?m=1

 

The problem is that we have no reason to think that we're unusual, and the Fermi paradox basically asks where everybody else is. The 'great filter' theory suggests that there's a thing or things which wipe almost every species out eventually (something to do with very early evolution, not becoming sexually dimorphic, not developing intelligence, self-destruction, AI disasters, an all-powerful and malevolent species of aliens who wipe out any lesser life forms that dare to leave their solar system, etc). There are loads of good candidates for what this could be, and ideally as a species we want them to be behind us!

If we find microbial life on Mars then that wipes out a whole bunch of filters. Some kind of vertebrate-adjacent thing on Europa would be extremely cool, but an absolute nightmare in terms of filters. Basically, the more advanced the life we find close to us, the higher the possibility that there's a great cosmic filter which we haven't hit yet. There was a much better explanation linked on another thread a few days ago.

 

Could there be technology to stop the core of a planet magnetically. That's the reason Mars is a dead planet. It's core stopped. Maybe there are Aliens living on a moon base that have the ability to freeze a core when a race gets to a certain level of being.