re: Another Earth-Sized Planet in Our Solar System!?
"NASA violently opposed the idea of another planet beyond Pluto for two decades. Now suddenly it's possible!? What gives? Have they been lying to us all this time?"
I don't think it's true that "NASA violently opposed the idea of another planet beyond Pluto". I can't imagine NASA being opposed- maybe someone at NASA thought it was unlikely- but this isn't even a "NASA" issue.
Got any evidence of your assertion?