Question

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?

1) Planets orbit in ellipses with low eccentricity.
2) Planets have cleared the neighborhood around their orbit.
3) Planets orbit the Sun.
4) Planets are approximately spherical.
5) Planets orbit in or very near the ecliptic plane.

Answer 1

Pluto does not clear the neighborhood around its orbit, which is one of the characteristics of planets.

Step-by-step explanation:

Pluto does not meet the characteristic of clearing the neighborhood around its orbit, which is one of the criteria for a planet. According to the International Astronomical Union (IAU), a planet must have sufficient mass to assume hydrostatic equilibrium, be in orbit around the Sun, and clear the neighborhood around its orbit. Since Pluto shares its orbit with other objects in the Kuiper Belt, it does not meet this criterion and was reclassified as a dwarf planet.