Communications with planets outside the solar system are most likely to be achieved using
A) spacecraft of the kind that went to the moon.
B) spacecraft that travel with the speed of light.
C) spacecraft that travel faster than light.
D) radio waves.

Question

Quizplus · Accepted Answer

Radio waves are the most commonly used method of communication with other planets because they can travel long distances through space and can be received by radio telescopes on Earth. While spacecraft could potentially be used for interstellar communication, they are not practical for long-distance communication due to limitations in speed and distance. Faster-than-light travel is currently considered impossible according to the laws of physics.

Communications with Planets Outside the Solar System Are Most Likely