NASA: National Aeronautics and Space Administration


Ask an Astrobiologist
"I'm wondering if there has been any life discovered on Earth that is not DNA based (life that has evolved in extreme environments, for example). "
  1. Question

    Can people talk in space without the aid of communication devices?

    No, sound needs a media to propagate. Sound can not travel in the vacuum of space. Sound waves, unlike light, are essentially compression waves, needing molecules to compress and decompress against in order to move. In a vacuum, there are no molecules. However, the confines of the shuttle, the space station, and other artificial environments possess a medium like air that sound is able to propagate through and hence people are able to communicate in normally. In the emptiness of space, however, sound waves are unable to travel, and no natural speech communication is possible.
    February 22, 2002

    1. Tell us what you think!


      It's your Astrobiology Program: please help us out by sending comments on what's here, and ideas for new features.

    Page Feedback

    Email (optional)
    Comment