Spheres only have one diameter. Planets are a little different than spheres in that they tend to bulge at the equator, so the size of their diameter depends on where you measure it. Planets are usually measured along the equator, but you could measure them in an infinite number of places.
you take a zebra and die it blue
There are infinite amount of diameters.
Every 'plant' has a smaller diameter than Earth, because all plants grow on Earth. However, I think you mean 'planets' . in which case the smaller planets are Mercury, Venus, Mars, and Pluto. NB THe word 'planet' comes from Classical Greece, and means wandering star.
There are infinite diameters within a circle.
A circle has infinitively many diameters....
5
It takes Pluto 90,588 Earth days to make one full revolution around the sun.
Pluto takes 246.04 years to orbit the sun once
There are infinite diameters in a circle all of the same lengths.
243 years
9. (including Pluto).
240