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.
Pluto
Neptune, Pluto, Or planet X (Or Nibiru) are discovered. On the future, Nibiru is discovered. The Future Year: 2111
neptune i belive
It wasn't discovered to not be a planet, it was decided to no longer be a planet. Recently, the last 2 or 3 years scientist decided (not all) it was not an official planet.
Neptune.
The last planet to discover during the 20th century was Pluto. But it's a dwarft planet so it should maybe be Neptune.
Technically, yes. But, just a few years ago, scientists discovered a red, round, sphere-shaped hunk of rock that scientists believe may be a ninth planet(well, tenth planet if you count Pluto). It is still unclear if it really is another planet or not.
Neptune. (Note: Pluto was discovered later, but currently it is no longer recognized as a planet.)
Neptune, discovered on September 23rd 1846 . Pluto was discovered in 1930, but it is now not classified as a planet but is not classed as the second largest (so far discovered) object in the Kipper belt which extends beyond the orbit of Neptune where to date over a thousand minor planets have been discovered and are being discovered daily. so it is Neptune, because it is the farthest from us. Plus the other stuff the person said was hard to understand
The most metallic element on the planet is Francium. It is the last element to be discovered that was not made synthetically.
At the end of the 17th century the furthest planet known was Saturn, and it had been known in ancient times. Uranus was discovered in 1783, Neptune in 1846.