Pluto
the scenod to last dwarf planet is: ceres is the second to last DWARF PLANET i think.
The third to last plantet from the sun is planet Uranus.
The planet with a summer that last for 21 years is Uranus. All of the seasons on the planet last for this amount of time.
Neptune is the last
As we are discovering more and more exoplanets almost weekly, there will never be a "last" planet discovered.
The planet Neptune was the second last planet to be discovered in our solar system. It was officially discovered in 1846 by Johann Gottfried Galle, based on mathematical predictions by Urbain Le Verrier.
planet freeze
It is Neptune, now.
In our Solar System, the closest planet to the Sun is Mercury, and the furthest is Neptune.
The last planet to discover during the 20th century was Pluto. But it's a dwarft planet so it should maybe be Neptune.
Pluto
jupiter