Odd one out
Pluto is the odd one out.
Some even say that it isn't a planet because it is smaller than the Moon.
Pluto is comparable to an inner planet in density and rockiness, but, having an elliptical orbit ranging from 30 to 50 AU from the
Sun, its average surface temperature is -230 °C.
Note how Pluto's elliptical
orbit loops inside Neptune's.