ESA has released "sonifications" of the telemetry sent back by the BepiColombo Mercury probe during its April 20, 2020 flyby of Earth. Sounding like a series of atonal symphony pieces, the five audio recordings were captured by two instruments installed on one of the two linked orbiters of the European/Japanese deep-space mission.
Now on the first leg of a seven-year journey to the solar system's innermost and smallest planet, the joint ESA/JAXA BepiColombo mission to Mercury was launched on October 20, 2018, and is expected to reach its final destination in 2025. To achieve this while using a relatively small booster rocket and ion thrusters, the unmanned spacecraft will execute nine planetary flyby maneuvers of which the Earth encounter was the first. The rest will include two flybys of Venus and six of Mercury before reaching its final orbit.
During the April flyby, some of the instruments on JAXA’s Mercury Magnetospheric Orbiter were active to take advantage of the opportunity to calibrate them before reaching Mercury. These included the Italian Spring Accelerometer, which measures changes in the spacecraft's velocity in several directions, and the MPO magnetometer, which measures the magnetic fields the probe is flying through.
Each of the data recordings was converted to audio and adjusted to fall within the range of human hearing. In addition, the timing was compressed to squeeze up to eight hours into a minute or less of audio.
The sonifications include accelerometer data as BepiColombo approached the Earth from an altitude of 256,39 to 129,488 km (159,300 to 80,460 mi), another audio track as the craft passed within an altitude of 12,689 km (7,885 mi), and a third as it passed through the Earth's shadow. Meanwhile, the MPO magnetometer sent back data as BepiColombo passed through the shockwave of the Earth's magnetosphere. The fifth audio recording is based on the same magnetometer readings, but with the sound of the spacecraft's reaction wheels that help it to maintain attitude left in instead of filtered out.
The video below is the sonification of BepiColombo passing through the Earth's shadow. The rest of the collection can be found here.
Source: ESA