Thousands of light-years away, in a region where new solar systems are still taking shape, a cloud of molecular gas is singing. With modern science, we can play along.
On the evening of 13 May 2026, in the quiet of Aalto University's Metsähovi Radio Observatory (MRO), a sound artist and ambient composer Heikki Lindgren with scientists Joni Tammi, Derek McKay and Jere Raassina came together for a live performance created directly from the sound of an astronomical phenomenon – an astrophysical maser.
At the heart of the experiment are phenomena that have long fascinated astronomers: astrophysical masers. They arise in cosmic clouds of molecular gas where stimulated emission amplifies their energy into an exceptionally intense and narrow radio-frequency band. They are the radio-frequency counterpart of laser emission, but they are detectable only with radio telescopes. This makes them observable with an unusual precision, and it is why they became such a compelling musical starting point. Where much of the sky is broad and noisy, a maser sings on a single, clear “note”.
Masers are often found in star-forming regions deep in space. They offer a unique insight into the mechanisms of planetary system formation, including those that gave rise to our own solar system, which gives them a special significance. To turn a maser into music, to “play” it, is to improvise with the same physics that made us possible.
Bringing a signal from deep space into a live performance took months of preparation. Staff scientist Derek McKay developed the code used to integrate a live audio signal from the masers observed with the Metsähovi Compacy Array (MCA) telescopes. For this experiment, the team selected the maser source G133.949+1.064, chosen because it produces the clearest signal accessible with the MCA.
The maser's signal was then sonified and routed into an Elektron Octatrack MKII sampler for real-time musical processing and the creation of harmonies. Nothing was pre-recorded or pre-composed, the entire electronic performance was shaped live, in the moment, from the raw signal arriving from space.
‘This nicely illustrates the nature of technical research: based on an idea, you start pushing equipment into uses it wasn't designed or intended for,’ says Joni Tammi, Senior Scientist, project coordinator on behalf of Metsähovi Radio Observatory.
‘And when problems arise, you solve them on the fly or figure out ways to work around them.’
The signal did not perform alone as sound artist and ambient composer Heikki Lindgren combined the live electronics with improvisation on the jouhikko, a traditional Finnish–Karelian bowed lyre, an instrument whose own ancient voice met the voice of the distant stardust.
Throughout, the limitations of the measuring instruments remained perceptible. The team let those constraints stay audible, and they gave the piece a sense of humanity, making the boundaries of the system part of the music. The technology stayed present in the art, and the two spoke to each other. As Tammi puts it:
‘The limits of the equipment we found during this proof-of-concept test will help us develop and improve our methods.’
The team believes this was the first time a live musical improvisation was performed with the signal of a maser. Earlier projects have turned prerecorded radio-telescope data into music; here, maser was played live – as the project puts it: stardust listening to stardust, across millennia and thousands of light-years.
For Lindgren, the appeal lay in working with the uncertain. ‘This has been an amazing opportunity to explore new tools to create sound art,’ he says. ‘I feel that we are at the core of avant-garde music trying new forms to produce sound.’
What he could not plan for was the sound itself. ‘I had some idea how the live sonification of radio telescope data would sound, but it turned out to be very different – small fractions of sine wave within one-second frames,’ he says.
‘It was all dealing with an unpredictable sound source, adapting to the moment.’
A cross-disciplinary collaboration of this kind is rarely straightforward, and it would not have been possible at all without curiosity on both sides. The enthusiasm and dedication of Joni Tammi, Derek McKay and Jere Raassina at Metsähovi Radio Observatory toward this artistic endeavour made the experiment possible, a reminder that measurement and wonder can share the same dome.
The collaboration with researchers at Metsähovi and Heikki Lindgren is not a one-off. Most recently, it culminated in the artwork “Sonic Universe,” presented at the Siirtymä Ambient Festival in Tampere in September 2026. The piece is based on the sonification of quasars and blazars, drawing on decades of MRO’s observational data. Follow the collaboration on Instagram: @rastrsound.
The sonification experiment was carried out with the participation of:
Heikki Lindgren – Sound artist & composer
Melanie Lindgren – Producer (off-site)
Joni Tammi – Senior Scientist, project coordinator on behalf of MRO
Derek McKay – Staff Scientist, MCA principal investigator, MRO
Jere Raassina – Doctoral researcher, MCA engineer, MRO
Hannu Karjalainen – Documentation & Edition
Vesa Turunen – Custom VTuR sound system design
Metsähovi Radio Observatory is the only astronomical radio observatory in Finland. Metsähovi’s main instrument is the 14-metre radio telescope, which is used around the clock, every day of the year. Its observational data is used, e.g., for studying active galaxies, the Sun, and the rotation of the Earth.
