The sounds of BepiColombo’s sixth flight previous Mercury

Take heed to the ESA/JAXA BepiColombo spacecraft because it flew previous Mercury on 8 January 2025. This sixth and last flyby used the little planet’s gravity to steer the spacecraft on target for getting into orbit round Mercury in 2026. 

What you possibly can hear within the sonification soundtrack of this video are actual spacecraft vibrations measured by the Italian Spring Accelerometer (ISA) instrument. The accelerometer information have been shifted in frequency to make them audible to human ears – one hour of measurements have been sped as much as one minute of sound.  

BepiColombo is all the time shaking ever so barely: gas is barely sloshing, the photo voltaic panels are vibrating at their pure frequency, warmth pipes are pushing vapour via small tubes, and so forth. This creates the eerie underlying hum all through the video.  

However as BepiColombo will get nearer to Mercury, ISA detects different forces performing on the spacecraft. Most scientifically attention-grabbing are the audible shocks that sound like brief, comfortable bongs. These are brought on by the spacecraft responding to getting into and exiting Mercury’s shadow, the place the Solar’s intense radiation is immediately blocked. Certainly one of ISA’s scientific objectives is to observe the adjustments within the ‘photo voltaic radiation strain’ – a pressure brought on by daylight putting BepiColombo because it orbits the Solar and, finally, Mercury. 

The loudest noises – an ominous ‘rumbling’ – are brought on by the spacecraft’s giant photo voltaic panels rotating. The primary rotation happens in shadow at 00:17 within the video, whereas the second adjustment at 00:51 was additionally captured by one of many spacecraft’s monitoring cameras. 

Faint seems like wind being picked up in a telephone name, which develop extra audible round 30 seconds into the video, are brought on by Mercury’s gravitational discipline pulling the closest and furthest components of the spacecraft by completely different quantities. Because the planet’s gravity stretches the spacecraft ever so barely, the spacecraft responds structurally. On the similar time, the onboard response wheels change their velocity to take care of the spacecraft’s orientation, which you’ll be able to hear as a frequency shift within the background.    

That is the final time that many of those results might be measured with BepiColombo’s largest photo voltaic panels, which make the spacecraft extra prone to vibrations. The spacecraft module carrying these panels is not going to enter orbit round Mercury with the mission’s two orbiter spacecraft. 

The video reveals an correct simulation of the spacecraft and its route previous Mercury in the course of the flyby, made with the SPICE-enhanced Cosmographia spacecraft visualisation tool. The inset that seems 38 seconds into the video reveals actual pictures taken by one in every of BepiColombo’s monitoring cameras.

Learn extra about BepiColombo’s sixth Mercury flyby 

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