What is one characteristic of a planet?

One characteristic of a planet is that it is a celestial body that is in orbit around the Sun. This definition is central to understanding what distinguishes planets in our solar system. Specifically, planets follow a stable, elliptical path around the Sun due to the gravitational pull of the Sun. This orbital relationship is foundational in astronomy, as it differentiates planets from other celestial objects such as stars, which emit their own light, or moons, which orbit planets rather than the Sun directly.

In addition, identifying planets based on their orbits helps categorize them distinctly, aligning with the International Astronomical Union's definition of a planet, which requires it to maintain this orbit around a star, in this case, our Sun. Therefore, an object's classification as a planet is inherently tied to its orbital dynamics within the solar system.