The Pioneer and Voyager spacecraft were used to search for planets beyond Pluto.What property of such planets was searched for by the spacecraft?
A)Their gravitational attractions
B)Visible light reflected by them
C)Radio emission from them
D)Eclipses of the Sun by them

Question

Quizplus · Accepted Answer

The Pioneer and Voyager spacecraft searched for planets beyond Pluto by detecting their gravitational attractions, which could affect the trajectories of the spacecraft.

The Pioneer and Voyager Spacecraft Were Used to Search for Planets