Question

Why is pluto no longer considered a planet?

a. its orbital path is not clear.
b. it is easier to remember 8 planets than 9.
c. it isn't spheroid in shape.
d. its orbit is too eccentric. it is too small.

Answer 1

Pluto was reclassified as a dwarf planet because it does not meet the IAU's criteria for a planet as it has not cleared the neighborhood around its orbit, despite meeting the other characteristics. This decision has been subject to debate among both astronomers and the public.

Step-by-step explanation:

Pluto is no longer considered a planet because it does not meet all the criteria set by the International Astronomical Union (IAU) for planet classification. Specifically, Pluto did not fulfill the third criterion, which requires a planet to have cleared the neighborhood around its orbit.

The defining characteristics of a dwarf planet include being in orbit around the Sun and having sufficient mass to maintain a nearly round shape, but unlike planets, dwarf planets do not clear their orbital paths.

The International Astronomical Union's redefinition of a planet in 2006 led to Pluto's reclassification due to its small size and the discovery of other similar bodies, such as Eris and Makemake, in its vicinity. This decision has sparked debates among astronomers and the public about Pluto's status and the nature of classification in our solar system.