NASA's Voyager 1 Space Probe Detects 'Persistent Hum' 14 Billion Miles From Earth The sound picked up by NASA could be a result of oscillating plasma waves. By Edited by Gadgets 360 Newsdesk | Updated: 12 May 2021 16:18 IST Photo Credit: NASA/JPL-Caltech Highlights The sound could be a result of plasma waves Voyager 1 is designed for interstellar research NASA's Voyager 1 probe has picked up an uncanny humming sound coming from space. NASA launched the Voyager 1 space probe 44 years ago and today it is the most distant human-made object from Earth, after exiting our solar system nine years ago. Since then, it has been exploring the near-emptiness of interstellar space and sending back valuable data to help us understand the world outside our solar system. Scientists now say instruments aboard the distant spacecraft have detected a “persistent hum” generated by the constant vibration of small amounts of gas in interstellar space. According to research published in the journal Nature Astronomy, this persistent monotonous humming is the sound of plasma waves oscillating and it is very weak.