Re: So um, could it be that some (or even much)
of the present surface is (um) younger than presupposition allows...?
Questioning assumptions is a good thing, it seems to me. Why should anyone believe, for example, that a surface on Mars is "ancient" rather than (relatively) recent?
Can anyone present evidence of actual cratering rates on Mars now and over time, and can anyone be certain of the cause of all cratering on Mars? I say "no."
If that's so then all the standard dating efforts must be questioned.
Doing that could upend everything.
But it's been done many times before, and yet the world still turns, the stars still shine!
Cheers, B R Felix