Question

which event helped astronomers calculate the mass of pluto correctly?
studying pluto’s gravitational force on charon
the discovery kuiper belt
xena and gabriella changing their names
voyager 2’s exploration of neptune

Explanation:

Calculating a celestial body's mass relies on gravitational interactions with orbiting objects. Charon is Pluto's largest moon, so studying Pluto's gravitational force on Charon (via orbital mechanics) allows astronomers to derive Pluto's mass. The Kuiper Belt discovery, name changes of other objects, and Voyager 2's Neptune mission are unrelated to Pluto's mass calculation.

Answer:

studying Pluto's gravitational force on Charon