On June 13, 2019, the official count of known exoplanets passed 4000! To celebrate, we have animated their discoveries in time and converted them into music. A circle appears at the position of each exoplanet as it is discovered with a colour that indicates which method was used to find it (see below). The size of the circle indicates the relative size of the planet’s orbit and the pitch of the note indicates the relative orbital period of the planet. Planets with longer orbital periods (lower orbital frequencies) are heard as low notes and planets with shorter orbital periods (higher orbital frequencies) are heard as higher notes. The volume and intensity of the note depends on how many planets with similar orbital periods were announced at the same time. The discovery of a single planet will be quiet and soft while the discovery of many planets with similar periods is loud and intense. The quiet background hum is created by converting the colours of bright stars that appear in the Milky Way into sound.

Radial Velocity (Pink), Transit (Purple), Imaging (Orange), Microlensing (Cyan), Timing Variations (pulsar, transit, eclipse, pulsation) (Red), Orbital brightness Modulation (Yellow), Astrometry (Grey)

This was featured as the Astronomy Picture of the Day on July 10, 2019 and has been viewed by over 1 million people on Youtube and Instagram! Check out the fantastic article about it by Phil Plait for Bad Astronomy and an excellent video explanation by Anton Petrov!