• Question: If sound can’t travel in space then how can astronauts communicate to Earth?

    Asked by S.B123 to Stephen, Sita, Rory, Hannah, Brian, Alison on 5 Mar 2019.
    • Photo: Hannah Currivan

      Hannah Currivan answered on 5 Mar 2019:

      Astronauts communicate to Earth using radio and internet!!!! When in the International Space Station or on a space walk astronauts communicate to Earth by Radio. 🙂 They also have access to the internet on board the International Space Station by connecting to a computer (mirroring) on Earth. 🙂

    • Photo: Stephen O'Connor

      Stephen O'Connor answered on 5 Mar 2019: last edited 5 Mar 2019 1:31 am

      Good point! Sound needs a medium in which to travel and because space is a high vacuum environment it can’t travel there.
      When an astronaut is inside a space suit, sound waves can travel in their helmet because it is partially pressurised. There are devices inside the helmet that converts their voice (sound waves) into radio waves (electromagnetic waves) which are transmitted to antennae on Earth and then re-converted back into sound waves for people to hear. Much the same way that when a radio broadcaster speaks into a microphone in their studio, the sound waves are converted into radio waves and broadcast to antennae commonly found in homes and cars. The radio waves are then converted back into sound waves that we hear with our ears.
      As Hannah pointed out, they also use the internet to communicate from inside the International Space Station.

    • Photo: Rory Scarrott

      Rory Scarrott answered on 5 Mar 2019:

      They use radio waves and sometimes other forms of electromagnetic radiation to get their words to Earth.

      Similar to a mobile phone, the astronaut talks into a device which converts sound into not-sound (electromagnetic waves). These can travel through space and can carry all the details of the astronauts voice back to Earth. On Earth a second device converts it back to sound waves and folks listen in.

    • Photo: Sita Karki

      Sita Karki answered on 5 Mar 2019:

      Sound is mechanical wave and it cannot travel in space. Astronauts use electromagnetic waves which can travel in space. There are many kinds of electromagnetic waves such as radar, x-rays, gamma rays, radio waves etc.

    • Photo: Alison Dufresne

      Alison Dufresne answered on 5 Mar 2019:

      I second what everyone said!