Does anyone know the current theories about why the features are so huge? And about how widely it's believed that Mars did have plate tectonics?
Edit: Thanks, guys. That helps a lot!
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You may have noticed that the tags have changed a bit. This is because I, genius, somehow managed to delete them all while tagging old posts, and had to start from scratch (I'm still in February).
I'm going to change tag permissions so only maintainers can tag posts until I've got it all sorted out.