What happened to Pluto?

Pluto was reclassified as a dwarf planet in 2006 by the International Astronomical Union. This decision was made because Pluto did not meet all the criteria required to be classified as a full-fledged planet. Pluto is now considered the largest object in the Kuiper Belt, a region of the solar system beyond Neptune that is home to many small icy bodies.

In 2006, the International Astronomical Union (IAU) reclassified Pluto from a planet to a dwarf planet. This decision was made after a lengthy debate about the definition of a planet. The IAU's definition of a planet requires an object to meet three criteria:

- It must orbit the Sun.
- It must be large enough to have a round shape.
- It must have "cleared its orbit" of other objects.

Pluto meets the first two criteria, but it does not meet the third. Pluto's orbit is intersected by the orbits of several other objects, including the dwarf planet Eris. This means that Pluto has not cleared its orbit of other objects, and therefore does not meet the IAU's definition of a planet.

The IAU's decision to reclassify Pluto was controversial. Some astronomers believe that Pluto should still be considered a planet, while others believe that the IAU's decision was the right one. The debate over Pluto's status is likely to continue for many years to come.