Description of the image: The star TRAPPIST-1a and its 7 terrestrial planets depicted with their respective sizes but the distance from the star is not to scale.
N.B.: TRAPPIST (Transiting Planets and Planetesimals Small Telescope) is a network of 2 robotic telescopes. One telescope is located at the La Silla Observatory (Chile) and the second telescope at Oukaïmeden (Morocco).
In the confusing and turbulent world around us, there are regularities that allow us to make sense of the apparent chaos. For example, we notice that Earth orbits the Sun regularly in a year, that days follow nights, that the nautilus builds its shell in spirals, or that bee cells are hexagonal...
All civilizations have been on the lookout for these regularities, rhythms, repetitions, and patterns that astonish and reassure us. They allow us to believe that there is order or design in our observable Universe.
Throughout history, these regularities, whether contingent or accidental, have inspired philosophers, physicists, mathematicians, and especially musicians.
When we talk about regularities, we think of sounds. In music, an octave corresponds to a doubling of frequency f, 2f, 3f, etc. These frequencies that are multiples of a given frequency are called harmonics. For example, the note C has a frequency of 260 Hz, and the next C is at 520 Hz. The note G has a frequency 1.5 times that of C, the next G is equal to 3 times C, etc. These regularities are sufficient to establish musical harmony.
The TRAPPIST stellar system, discovered in 2016 using the transit method, is 7.6 billion years old and is located in the constellation Aquarius, 39.5 light-years away. This system consists of an ultra-cool dwarf star called TRAPPIST-1a and at least 7 rocky planets (TRAPPIST-1b, TRAPPIST-1c, TRAPPIST-1d, TRAPPIST-1e, TRAPPIST-1f, TRAPPIST-1g, TRAPPIST-1h).
Three of these are located in the habitable zone of the star, and TRAPPIST-1e has a density close to that of Earth, and it presumably has an iron core and a liquid or icy ocean.
Using a computer model, scientists simulated the planetary orbits and discovered that the 7 planets are in perfect orbital harmony. In other words, each planet has simple ratios with the orbital periods of its neighbors. When the outermost planet TRAPPIST-1h completes 2 orbits, its neighbor TRAPPIST-1g completes 3 orbits, TRAPPIST-1f completes 4 orbits, TRAPPIST-1e completes 6 orbits, TRAPPIST-1d completes 9 orbits, TRAPPIST-1c completes 15 orbits, and TRAPPIST-1b completes 24 orbits. The entire system moves with a very beautiful regularity.
Description of the video: A team of NASA researchers and musicians transformed the orbits of the seven TRAPPIST-1 worlds into music. No other known planetary system harbors so many resonant worlds. Computer simulations suggest that the planets should have collided very quickly after their formation. But resonance apparently saved them, according to Dan Tamayo, a researcher at Cornell University in Ithaca, New York.
The planets of the TRAPPIST-1 system are thus in perfect orbital resonance, and these harmonious orbits can be translated musically, with notes. TRAPPIST-1b corresponds to the note B (B in Anglo-Saxon form), TRAPPIST-1c corresponds to the note C, TRAPPIST-1d corresponds to the note D, etc.
Each planet plays a note per orbit when it passes between us and its star, and a rhythmic beat resonates each time it passes in front of its neighbor.
As each planet resonates with its neighbors, the entire system forms a chain of harmonic resonance.
This is shown (in accelerated form) in this dazzling and melodious animation where the seven planets waltz in almost perfect synchrony.
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