PIMSO 2025 - Science - Senior Secondary - National Round Question 29
PIMSO Science · PIMSO 2025 - Science - Senior Secondary - National Round
Despite its having been classified as a planet for 75 years, Pluto was abruptly demoted to the status of a dwarf planet after similar objects were discovered in the Kuiper Belt. What standard requirement is found lacking about Pluto to be classified as a planet?
The object must be in orbit around the Sun
It must have cleared the neighborhood around its orbit.
The object must be massive enough to be rounded by its own gravity.
It must have a surface characterized by mountains, valleys, and craters.