Distant Sedna Raises Possibility of Another Earth-Sized Planet in Our Solar System

space.com...

"Perhaps there's more than one planet out there," Marsden said. "Who knows? But let's suppose it is something of an Earth mass, maybe even a few Earth masses. A close approach could throw this object [Sedna] from something more circular into something more eccentric."

Marsden says such a scenario leaves open the question of how an Earth-sized planet could have formed so far from the Sun, where raw material should have been sparse, according to current theory.

Brown said an Earth-sized planet is indeed a possibility. But his team's calculations put it at about 70 AU.

"We think it's unlikely, because we think we would have found it by now," Brown said in a telephone interview.



It seems that the astronomers are saying that they really have no clue to what the possibilities are but then their ego steps up and contradicts that.
Space is BIG. Our solar system is BIG.
Anything is possible.
I wouldn't rule out the possibility of a larger planet out there.
What do you think?

Nor would i, i think its amazing what they're finding out there. Like you said the solar system is big and we probably vastly underestimate it. Im hoping they discover more and we learn a bit more about our own solar system before advancing too much foreword.