For over 40 years, NASA’s Voyager 1 probe has been traveling through space to observe and explore our solar system—and beyond! While originally it was only intended to fly by Jupiter, Saturn, Uranus, and Neptune, Voyager 1 has kept moving onwards, farther than scientists could have anticipated.
In 2012 it made history as the first ever man-made object to enter interstellar space - far outside the cozy bubble of our solar system. Now in 2021 Voyager 1 is almost 153 “astronomical units” from the sun. An astronomical unit is what we call the distance between the sun and Earth, so that means it is now 153 times as far away as Earth is from the sun! Pretty far-out!
What sounds can we hear from beyond the cosmos?
So far we haven’t picked up any alien radio stations. But scientists say that the spacecraft has recorded what they describe as a “humming” sound from deep space. What could the noise be? Where could it be coming from?
Researchers say that the 'humming' is actually the space probe picking up vibrations of gas found in the near-emptiness of interstellar space. These vibrations are also known as 'plasma waves'.
Interstellar space is filled with all kinds of plasma waves, big and small. As these waves travel through space, they vibrate the particles around them and create a high pitched ringing. With its huge 30-foot-long antenna, Voyager 1 can pick up these frequencies and broadcast them back to Earth for us to hear.
Stella Ocker, a member of NASA’s Voyager 1 team, says that the plasma waves are too weak to be heard with a human ear. “If we could hear (the hum)," she said, "it would sound like a single steady note, playing constantly, but changing very slightly over time."
More to discover
In the past, Voyager 1 had detected powerful plasma waves that were linked to flares from our sun. But these new findings suggest that these vibrations could just be a normal thing in interstellar space, unrelated to any solar activity from the sun.
We still have a lot of mysteries to solve about what’s going on so far away from our planet, but Voyager 1 is helping us to discover new info every day.
Stella Ocker says about the Voyager probe: "It’s the engineering gift to science that keeps on giving.”