hammerforscale asked: I know what you mean. The fact that there's evidence of a huge fault on Mars is exciting enough, surely? Without having to over extrapolate to a half-baked theory on plate tectonics?

I certainly find the idea of an enormous fault on Mars to be very exciting!

But if there can be enormous Martian volcanoes without fully active plate tectonics, there can surely also be enormous Martian faults. I am as intrigued as anyone else by the larger-scale processes producing these landforms, but with the amount of data that exists now, I think jumping right to, “It’s plate tectonics, there are two whole plates!” is premature.

It’s also interesting that they’re focusing so much on this one boundary. What about the boundary on the other side of the plates, if they are plates?