Universe

School in 2006, you will remember something.  Like the same sentence.  Which was used to teach children the order of the planets in the solar system - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. But in these days elementary school, there is no name of pluto in this list of name.What happened to Pluto that drove it out of the solar system as a planet?  It is not at all the case that this poor planet has moved away from our galaxy or has become the home of another galaxy. It is still present in the corner of our solar system as it used to be as cold and distant as before.  So what kind of change has taken place that has stripped Pluto of its status as a planet?  We know more about space than we did a hundred years ago.  Pluto itself was discovered in the 1930s, so it has not changed as much as a planet before, yet it has not changed the fact that there is something strangely natural about the destruction of a planet.  Is....