Hard to scrape from mind that there are only 8 planets.

http://news.bbc.co.uk/2/hi/science/nature/5282440.stm

That was a nice piece of humor by Mr. height! Our generatin has been taught that nine planets make a solar system. Hence,I still say you worth losing two points.:) Tyati belanai aath wota huncha bhaneyko bhaye po dus aauthyo.

I bet will take time for people ,who have been taught Pluto as a ninth planet, not to consider Pluto as a part of the planetary system.

Well, its a fact that the way we explore science is much more intense than before. There are many instances when old theory has to revive due to the new understanding. For example, no body wanted to accept the origin of quantum mechanics to replace the classical newtonian mechanis, but also no body could stop it. But this instatce of Pluto is really deep into our thinking, it may be hard to explain a kid that, what he learnt till now was wrong and there are only 8 plantes. I would explain by saying that, before people misrcognized a big rock as a 9th planet, but there are thousands of such rocks, so it cannot be in the same category as other 8 plantes.
A less name to memorize......