Which moon is known to be the binary star of Pluto?

Which moon is known to be the binary star of Pluto?

• A. Europa
• B. Charon
• C. Ganymede
• D. Triton

Answer: (B)

Charon is known as the binary companion to Pluto due to its significant size relative to Pluto. This relationship is unique because Charon is approximately half the diameter of Pluto, which means that the gravitational interactions between the two bodies are quite distinct compared to the typical satellite and planet relationship. Rather than Pluto simply orbiting a singular point in space, both Pluto and Charon actually orbit around a shared center of mass, known as the barycenter, which lies outside of Pluto itself. This dynamic gives them the characteristic of being classified as a binary system in astronomy.

In contrast, the other choices are moons of different celestial bodies that do not share this binary relationship with Pluto.