NASA’s Voyager 1 spacecraft has detected a strange humming sound emanating from space. The Voyager 1 space mission was launched by NASA 44 years ago, and it is now the farthest remote human-made object from Earth, having exited our solar system nine years ago.

It has been exploring the near-emptiness of interstellar space since then, giving back crucial data to help us comprehend the universe beyond our solar system.

Scientists have discovered a “continuous hum” caused by the steady vibration of minuscule quantities of gas in interstellar space, according to equipment aboard the faraway spacecraft. According to research published in the journal Nature Astronomy, this constant monotonous humming is the sound of oscillating plasma waves and is quite feeble.

A team led by Cornell University is analyzing data received by Voyager 1 from 14 billion miles away. Stella Koch Ocker, a doctorate student at Cornell University in New York and one of the study’s authors, said the sound was very weak and monotonous due to the narrow frequency spectrum. You can listen to the sound below.

The Voyager 1 probe sailed past Jupiter in 1979 and Saturn the following year before passing the heliopause — the boundary between the solar system and interstellar space — in August 2012. It has now approached the interstellar medium.

Previously, after crossing the heliopause, the Plasma Wave System aboard Voyager 1 discovered oscillations in the gas, but those were driven by our Sun.

“The interstellar medium is like a gentle rain,” said James Cordes, senior author of the study, in a statement posted on Cornell University’s website.

Researchers now believe that there is more activity than previously assumed in interstellar gas. Scientists may use Voyager-1 data to better understand the interactions between the interstellar medium and the sun’s solar wind, which is a constant stream of charged particles.

Shami Chatterjee, a Cornell research scientist, stated why continual surveillance of interstellar space is crucial, saying that scientists have never had the opportunity to analyze interstellar plasma, but they now do since Voyager 1 is passing through them and sending back the crucial data.