Why is Pluto no longer a planet?

Pluto was reclassified from a planet to a dwarf planet in 2006.

A dwarf planet is a celestial body that -orbits the sun, has enough mass to assume a nearly round shape, has not cleared the neighborhood around its orbit and is not a moon.

Pluto was originally classified as a planet in 1930 after astronomer Clyde Tombaugh noticed a small dot while comparing photographic plates of the sky.

At the time, astronomers didn’t have the technology to accurately measure Pluto’s size or composition, so they based their classification on its orbit and perceived size.

Pluto was considered the ninth planet in our solar system, but it was immediately considered an oddball because of its eccentric orbit and tilt.