Why should pluto be a planet?
I see. You are stuck with doing an assignment where you have to debate in favor of Pluto being a planet. Whether you want it to be (or not) has nothing to do with it. So: Planets are in orbit around the Sun. Pluto is in orbit around the Sun. Planets orbit the Sun in a “normal” direction (called prograde) which is the same as the direction of the Sun’s spin. Pluto orbits the Sun in the prograde direction. Planets are large enough to be spherical (their own gravity is stronger than the chemical bonds holding the stuff in place). Pluto is spherical. Planets have (in general) small satellites. Pluto has two small satellites. It also has a large “companion” that was called a satellite for a long time. It is called Charon (the Ch is pronounced as if it were a K). That is OK. Earth also has a satellite that is too big. Under an older definition, planets are big enough to show a disk when viewed in a telescope (this was a definition from the 1860s). It is because of that definition that a nebu
