Finding the sound of Earth’s winds

Celenie JauniauxCelenie Jauniaux
  28 July 2023

Our social media editor Peter Bickerton takes us behind the scenes of Life of Aeolus, a music project he supported on behalf of the European Space Agency.

What’s the perfect way to tell the story of the life of a wind satellite?

One that had so many intricate parts, orchestrated by expert teams across Europe, skilfully mastering instruments and data?

A music piece formed by a mixture of wind instruments seemed the perfect choice.

Much like Aeolus transformed our seemingly invisible winds into data that hugely improved weather forecasts, woodwind instruments turn breaths into beautiful sounds.

That idea became reality through the Life of Aeolus sonification. The result is beautiful.

Making the Life of Aeolus

Earlier in the year, we were introduced to composer Jamie Perera after a beautiful journal called Wild Alchemy featured ESA Aeolus Mission Manager Tommaso Parrinello in their Air Edition.

We initially teamed up to see how we might turn some Aeolus data into music. After linking him up with Daniel Santillan of EOX, Jamie produced an eerie soundtrack of the winds above Hunga Tonga’s dramatic eruption in 2022.

Who better to create the Life of Aeolus?

Again, Jamie and Daniel put their heads together to turn five years of a satellite mission into a half hour orchestral piece.

The task sounds monumental.

But bit by bit, it all came together.

Every day of Aeolus became a second of music.

Each layer of the winds Aeolus measured, in vertical profiles up to 30 km above Earth’s surface, were matched to the notes on a keyboard (imagine a keyboard on its side).

Ranges were then ascribed to musical instruments. Piccolos would play the tops of clouds, whilst the bassoon and bass clarinet would represent the layer closest to Earth’s surface.

In between, clarinets, flutes and oboes played Aeolus’s winds, and other data such as air temperature and pressure.

It’s much more complicated than this

Turning data into music – particularly five years’ worth of data – isn’t easy. In fact, it could quite easily sound like an unmelodious racket.

But sonification is an art as well as a science. There’s a balance to be struck between ultimate accuracy and musicality.

“It required some aesthetic decisions because having so many data playing at once could potentially sound quite cacophonous,” explains Jamie. “It’s a balancing act between having something that’s both accurate to the data and accessible to the audience.”

There were plenty of other considerations, and some quite ingenious ways to turn wind data into notes.

One nifty trick was choosing the right mode, a type of scale. Jamie went for the Lydian mode, which, he says “has an expansive, pioneering sort of feel to it, which was perfect for Aeolus.”

A beautiful end to a pioneering mission

As far as we know, this is the first time anyone has turned satellite data into an orchestral woodwind piece.

It’s fitting. Aeolus is a feat of European innovation and teamwork that put the first ever laser in space to measure global winds. After many trials and tribulations, it was a whopping success.

Weather forecasters used the data to fill gaps in weather data during Covid lockdowns, when planes (that would normally provide weather data) were grounded.

The same effect helped improve hurricane forecasts where it wasn’t possible to fly reconnaissance trips.

Now, ESA’s wind mission will return to Earth – in a pioneering attempt to improve space safety and sustainability for future generations.

Aeolus’s achievements are too many to list here. It’s best to enjoy them through the sounds of the wonderful mission that will see a follow-on launch within a decade.

All the best, Aeolus.

Find out more on ESA channels

Listen to the Life of Aeolus on SoundCloud

Watch the video on YouTubeRead the article on esa.int