To bring this idea to life, Tamayo, along with Canadian Institute for Theoretical Astrophysics astronomer Matt Russo, created an animation in which a piano note is played every time a TRAPPIST-1 exoplanet crosses in front of its star. The team then filled out the arrangement by adding a drum beat every time a planet overtakes a neighbor. The result, sped up so that the orbital frequencies reach the human hearing range in a process known as sonification, is a sort of astrophysical symphony, finely-tuned to ensure its own survival for billions of years.

As for how this cosmic ensemble could have formed, Tamayo and Russo think the planets probably migrated to their current positions after coalescing in a protoplanetary disk billions of years ago. “Planets form in disks of gas and dust, and as planets grow and interact with the surrounding disk, they move around relative to one another,” Tamayo said. “If this process is gentle enough, then planets can naturally tune all their orbital parameters to one another, just like the orchestra does before a symphony.”

Of course, this is just an idea to fall out of some models, and it needs to be verified with additional observations. But Tamayo thinks the planetary formation conditions around low-mass stars like TRAPPIST-1 may be calmer than those around larger, hotter stars like our Sun, making them “better able to form harmonious, long lived planetary systems.”


You can check out the details of Tamayo and Russo’s investigation in their new study (a pre-print is free to read on arXiv). Or, you can just enjoy the animation above, and imagine bioluminescent aliens dancing to the beat of this incredibly strange, undeniably beautiful star system.