Pluto continues to be excluded from new planet definition despite updated criteria

While a mathematical formula for determining whether a space object should be classified as a planet could make it easier to identify objects around other stars, it’s bad news for anyone hoping that Pluto will regain planetary status.

In 2006, the International Astronomical Union (IAU) infamously downgraded Pluto from a planet to a dwarf planet, leaving our solar system with eight planets, in a controversial decision. The IAU cited Pluto’s failure to clear out other junk in its orbit as a key factor in the decision.