Neil DeGrasse Tyson is an astrophysicist who doesn't believe in planets. Of course he knows that there are large objects circling the Sun. He just doesn't believe that picking out nine of them -- or eight, now that Pluto has been demoted -- has any scientific basis. There are far more interesting ways of dividing up the universe. For example, there are four bodies in our solar system that have atmospheres -- three planets and one moon of Saturn -- and having an atmosphere is far more interesting scientifically than simply being a big object because having an atmosphere raises lots of questions and possibilties. Being big raises nothing but the question, "Well, so how exactly big are you, anyway?"
It was rather sad that out of all the amazing development out of astronomy and astrophysics, the recategorization of Pluto got such a huge news and such large amount of effort among even astronomers. Compare that to what exactly is such an impact on the physics and astronomy content - NOTHING. That is why I said that this is an exercise in something that is utterly useless.