do you think that there is a planet is in our solar that scientists have not discovered yet?

Question: do you think that there is a planet is in our solar that scientists have not discovered yet?
- Keywords:
  discovery,
  planet,
  space
Asked by bigcheack to Ed on 20 Mar 2013. This question was also asked by mandf12.
- Edward Bovill answered on 20 Mar 2013:
  
  Our Solar System has been studied for hundreds of years now so we’ve discovered every object large enough to be a planet. Pluto was downgraded from a planet in recent years because it’s just too small (it’s moon is almost as big as it is!) and there are several other objects as big, or even bigger!, than Pluto. But none big enough to be called a planet.

Question: do you think that there is a planet is in our solar that scientists have not discovered yet?