The masses of Neptune and Uranus were first determined by:
A)observations of their motions around the Sun.
B)observations of their magnetic fields.
C)their densities divided by their volumes.
D)observations of the motions of their satellites.
E)their compositions.

Question

Quizplus · Accepted Answer

The masses of Neptune and Uranus were first determined by observing the motions of their satellites. The gravitational influence of these planets on their moons allowed astronomers to calculate their masses.

The Masses of Neptune and Uranus Were First Determined By