Perhaps we surface-dwelling life forms are the exceptions--bizarre mutations of the normally deep-dwelling archeabacteria that populate the interiors of planets all over the galaxy.
The interiors of planets all over the galaxy were repeatedly studied when new technology became available.
mnli hypothesis: The interiors of planets all over the galaxy were repeatedly studied when new technology became available. premise: Perhaps we surface-dwelling life forms are the exceptions--bizarre mutations of the normally deep-dwelling archeabacteria that populate the interiors of planets all over the galaxy.