The spacecraft Juno launched from Florida in the United States by NASA in 2011, and began making its way to the planet Jupiter over 365 million miles away.
The aim of its mission has been to learn all about what makes up the huge gas giant, learning all it can about its gravitational and magnetic fields.
Jupiter has 79 moons, which Juno joined in orbit around the solar system's biggest planet in 2016 to carry out its pioneering research. But as it passed one, Ganymede, it detected something very strange.
Tuning its plasma instruments towards the rock it picked up some fascinating and surprising frequencies.
What did Juno hear from Jupiter's moon?
The satellite heard a bizarre, sci-fi-like series of bloops, bleeps and a building rushing noise – some of the bleeps even sound like Star Wars' R2-D2.
Juno recorded a 50 second-long audio clip by converting the plasma waves generated by Ganymede's magnetic waves into sound waves audible to humans.
The pitch of the noise increases as Juno moves towards the largest moon in the Solar System, creating the feeling a collision is imminent then suddenly it breaks and the pitch begins to recede.
Scott Bolton, Juno principal investigator at the Southwest Research Institute in San Antonio, said: “This soundtrack is just wild enough to make you feel as if you were riding along as Juno sails past Ganymede for the first time in more than two decades."
As Juno flew into a different part of Ganymede's magnetosphere it picked up a sudden hike in frequency. Although research and analysis are still ongoing it is believed it could be caused by the satellite passing the moon's night side into its day side.
Juno has made over 30 trips around Jupiter at the time of writing, peering into the huge planet to learn what it can about the planet's composition, weather and natural phenomena.
It has also sought to build knowledge on its giant red and blue dots. The former is a hurricane bigger than earth – the latter a magnetic anomaly invisible to the human eye.
However, having collected lots of data in the last five years and its main mission completed, its attention is currently fixed on the moons.
This isn't the first time information has been gathered from Ganymede: the Galileo mission also paid it some attention, where it discovered the presence of its own magnetic field, making it the only natural satellite known to have one.
It is believed that below its huge sheets of ice, the moon has an iron-rich core and enormous salt oceans.
Research from the Juno mission has found that the ice varies between different parts of Ganymede, indicating that the composition of the planet is more complex and diverse than first thought.
Source: Read Full Article