When a formal definition of a planet in the solar system was adopted, Pluto was reclassified as a dwarf planet. What characteristic of planets does not describe Pluto?
A) Planets orbit the sun.
B) Planets are approximately spherical.
C) Planets have cleared the neighborhood around their orbit.
D) Planets orbit in ellipses with low eccentricity.
E) Planets orbit in or very near the ecliptic plane.

Question

Quizplus · Accepted Answer

Pluto has not cleared the neighborhood around its orbit, which is one of the requirements for a celestial body to be considered a planet according to the formal definition adopted by the International Astronomical Union.

When a Formal Definition of a Planet in the Solar