NASA's Juno spacecraft is getting ready to enter Jupiter's orbit on July 4, giving scientists their best chance ever to study the mysterious planet. But astronomers already have some data to puzzle over, with the spacecraft recording these haunting sounds as it approached the gas giant.

These strange, screeching and roaring sounds were captured by Juno's Wave instrument as the spacecraft crossed the boundary Jupiter's magnetic field on June 24, and they're both fascinating and chilling to listen to.

As weird as it might sound, the noise is actually the 'bow shock' caused when Juno entered the planet's immense magnetic field, which protects the gas giant from solar winds, just like our magnetic field here on Earth.

The sound is produced when the supersonic solar winds that are hurtling through the Solar System are suddenly slowed down and heated up as they plough into Jupiter's magnetosphere, resulting in bow shock - it's sort like the sonic boom produced when an aircraft exceeds the speed of sound here on Earth, and the compression waves coming off it combine to form a shock wave.

The bow shock recorded by Juno lasted about 2 hours, which is pretty impressive considering the spacecraft is travelling around 241,000 km/h (150,000 mph).


It wasn't until the next day that the Waves instrument recorded that Juno had officially crossed the magnetopause, which is where it's shielded from solar winds.

You can hear more of the alien sounds below:

And don't forget to watch live as Juno's attempts to make history and enter Jupiter's polar orbit. Better than fireworks!