The first notes in a YouTube video titled TRAPPIST Sounds emerge like the beginnings of a pop song: Four strong piano notes in C, seemingly poised to usher in a barrage of melancholy vocals. Instead, a second note joins in, then a third; by the fourth, the haphazard, off-beat quality of an avant-garde music piece begins to take form. One minute in, as a drum beat punctuates the dancing notes, the song picks up tempo and starts to hit its stride.
What sounds like an experimental orchestral work one might hear at a concert hall is actually the movement of a solar system, translated into sound. As the name suggests, the music traces the orbits of planets in the Trappist 1 planetary system, the discovery of which was announced by astronomers in February, along with the remarkable news that at least some of the planets have the right conditions for life. Yet even after the discovery, scientists have been puzzling over the planets’ rotation pattern–something that this musical accompaniment has proven to help.
The song and the accompanying video–the graphics of which provide the visual link to the planets–were created by Matt Russo, an astrophysicist and post-doctoral fellow at the University of Toronto Scarborough, who also happens to be the guitarist in the indie pop group Rvnners. Russo and his bandmate Andrew Santaguida created the piece from the data and findings of Daniel Tomayo, a postdoctoral researcher who occupies the office next door to Russo. Tamayo’s recent work has lead to a breakthrough in a question about the Trappist 1 planets’ orbits, and Russo’s musical animation could help further his colleague’s research.
Besides being a striking piece of information design on its own, TRAPPIST Sounds is most remarkable in the information that it visualizes: Tamayo’s findings. The scientist was solving for an inconsistency that had puzzled scientists since Trappist 1 was discovered earlier this year–namely, that although the planets orbited “in resonance” with one another, computer simulations showed that if the planets continued on that path, they would have been destroyed by each other in a few million years. Since the estimated age of the Trappist 1 dwarf star (the equivalent to the sun in our solar system, though smaller and colder) was estimated to be 3 billion to 8 billion years, the scientists knew something about their data was off.
Tamayo and his colleagues decided to look at the system a different way and see if they could get different results. In looking into the history of how the Trappist 1 planets were made, they found they were formed out of a disk of gas and dust. The disk then nudged the planets inward, which gave them stable “resonances;” in other words, the second planet completes five orbits in almost exactly the time the first planet makes eight, the third completes three orbits for every five from the second planet, and so forth. Looking back in time to simulate the formation of the system in its birth disc did the trick. After hundreds of computer simulations, they found that the system did stay stable for several billion years, which made more sense given the age of the star. While questions remain, the analysis lets the scientists go forward knowing they understand the basics of the system.
In an article for the New York Times, Tamayo explained his methodology in music terms: Trying to understand the way that the planets were formed was like an orchestra tuning its instruments before playing. Only after the “tuning” can they now move on to the task of keeping time. That process–discovering how the planets keep time with each other–became the basis for Russo’s musical animation. He and Santaguida assigned each planet a note, setting the note for the outermost planet at C. It plays each time the planet passes in front of the Trappist 1 star, resulting in a cacophony of planet-specific notes. Whenever a planet catches up to its neighbor, a drum beat sounds–a reminder of the planet’s resonance.
Fascinatingly, other planetary systems may not be the musical virtuoso that Trappist 1 has turned out to be. Russo tried the same software on Kepler 90, a star that also has a planetary system of seven exoplanets. (“It’s just horrendous,” he told the Times.) But if you’d like to try, the pair released the code for their software on GitHub.