Telescopes allow us to “see” space. Astronomers translate their digital data into images of a world that would otherwise be invisible to us.
For a rather different take on things, a NASA project is translating the data into sounds instead, allowing us to “listen” to the centre of the Milky Way as observed in X-ray, optical and infrared light. The process is known as sonification.
The animation above shows a region about 400 light-years across and 26,000 light-years from Earth. Press play, and you can hear an ensemble piece courtesy of the Chandra X-ray Observatory, the Hubble Space Telescope and the Spitzer Space Telescope.
As NASA explains it, the sounds represent the position and brightness of the sources. The light of objects located towards the top of the image are heard as higher pitches while the intensity of the light controls the volume. Stars and compact sources are converted to individual notes while extended clouds of gas and dust produce an evolving drone.
The crescendo happens at the bright region to the lower right. This is where the four-million-solar-mass supermassive black hole at the centre of the Galaxy, known as Sagittarius A*, resides, and where the clouds of gas and dust are the brightest.
The Hubble image outlines energetic regions where stars are being born, while Spitzer’s infrared image shows glowing clouds of dust containing complex structures. X-rays from Chandra reveal gas heated to millions of degrees from stellar explosions and outflows from Sagittarius A*. You can hear their individual contributions on NASA’s website.
The project has also produced sonified versions of the remains of a supernova called Cassiopeia A and, below, the famous Pillars of Creation located in Messier 16. Particular attention is paid to the structure of the pillars which can be heard as sweeps from low to high pitches and back. Again, there’s more detail on the NASA site.
Our take on things? The Milky Way sounds like a meditation tape, but the Pillars sound, well, a bit alien.