Why two persons from the moon surface cannot hear their voice while walking on it?

Two people on the moon cannot hear each other’s voices directly because there is no air on the moon to carry sound waves.

Sound needs a medium like air, water, or solid to travel. On the moon, there is vacuum, which means there is no medium for sound waves to move. Therefore, even if two astronauts shout, the other person will not hear them through air.

Reasons explained

• Moon has no atmosphere.
• Sound waves need a medium to travel.
• Vacuum blocks sound transmission.

This is why astronauts on the moon use radios and headsets with electromagnetic waves to talk, since radio waves can travel through vacuum.