Solar System: Hunt for the Missing Planet

The solar system and its planets seem like a familiar place. Yet scientists now think they've detected something huge lurking in the far reaches of the system we call home. Could it be that a missing, giant ninth planet orbits our sun in the dark reaches of space? We'll meet the astronomers hunting for this hypothetical world. Scientists who are only now beginning to understand how such a massive planet could have ended up so far away from the Sun - way beyond where science predicts planets can form. We join teams in the UK, Germany and the United States who are ...