Sounds of the stars: how scientists are listening in on space

For astronomers who are sighted, the Universe is full of visual wonders. From shimmering planets to sparkling galaxies, the cosmos is spectacularly beautiful. But those who are blind or visually impaired cannot share that experience. So astronomers have been developing alternative ways to convey scientific information, such as using 3D printing to represent exploding stars, and sound to describe the collision of neutron stars.The work demonstrates that efforts to boost inclusivity and accessibility can have wider benefits. This is true not only in astronomy; sonification has also yielded discoveries in other fields that might otherwise not have been made. Research funders and publishers need to take note, and support interdisciplinary efforts that are simultaneously more innovative and inclusive.The number of sonification projects picked up around a decade ago, drawing in researchers from a range of backgrounds. Take Kimberly Arcand, a data-visualization expert and science communicator at the Center for Astrophysics, Harvard & Smithsonian in Cambridge, Massachusetts. Arcand began by writing and speaking about astronomy, particularly discoveries coming from NASA’s orbiting Chandra X-Ray Observatory. She then moved on to work that centred on the sense of touch; this included making 3D printed models of the ‘leftovers’ of exploded stars that conveyed details of the physics of these stellar explosions. When, in early 2020, the pandemic meant she was unable to get to a 3D printer, she shifted to working on sonification.In August, NASA tweeted about the sound of the black hole at the centre of the Perseus galaxy cluster; the attached file has since been played more than 17 million times. In the same month, Arcand and others converted some of the first images from the James Webb Space Telescope into sound. They worked under the guidance of people who are blind and visually impaired to map the intensity and colours of light in the headline-grabbing pictures into audio.These maps are grounded in technical accuracy. The sonification of an image of gas and dust in a distant nebula, for instance, uses loud high-frequency sounds to represent bright light near the top of the image, but lower-frequency loud sounds to represent bright light near the image’s centre. The black hole sonification translates data on sound waves travelling through space — created by the black hole’s impact on the hot gas that surrounds it — into the range of human hearing.On 17 November, the United Nations Office for Outer Space Affairs will highlight the use of sonification in the space sciences in a panel discussion that includes Díaz-Merced and Arcand. This aims to raise awareness of sonification both as a research tool and as a way to reduce barriers to participation in astronomy. It’s time to wholeheartedly support these efforts in every possible way.alternative data representations cobble together support from various sources, often in collaboration with musicians or sound engineers, and the interdisciplinary nature of such work makes it challenging to find sustained fundingOn Friday, the journal Nature Astronomy will publish the latest in a series of articlesScientists in other fields have also experimented with data sonification.