It is said always to be a challenge for a musician to follow up a first monster hit. But Rosetta’s recording of the latest sounds from the singing comet, 67P/Churyumov-Gerasimenko, are as amazing as those released two years ago.
A day before the European Space Agency probe ended its mission by colliding with the comet, ESA put out a new “song” produced by mixing data collected over Rosetta’s entire time in orbit.
In mid-2014, soon after Rosetta arrived at 67P, some surprising vibrations were detected in the highly charged gases, or plasma, surrounding the comet’s nucleus.
They were picked up by the magnetometer on the Rosetta Plasma Consortium (RPC) suite of instruments, and are explained by the intraction between the flow of electrically charged particles from the Sun in the solar wind and the water vapour and other molecules escaping from the comet.
Although this phenomenon has been observed before in comet flybys by spacecraft, Rosetta’s encounter gave scientists their first chance to observe it over a long period of time as the singing comet approached, then retreated from the Sun, becoming more and then less active again.
The new recording of singing Comet 67P produced from plasma data. Original Data Credit: ESA/Rosetta/RPC/RPC-MAG. Sonification: Manuel Senfft (on behalf of the IGEP/TU Braunschweig).
Charlotte Goetz, of the Institute for Geophysics and extraterrestrial Physics at Technische Universität Braunschweig, in Germany, is part of the plasma-studying team, and she described the singing comet’s musical activity at a pres briefing attended by Skymania News at Rosetta mission control, the European Space Operations Centre, at Darmstadt, Germany.
She said: “As the comet moved closer to the Sun in 2015, it was pouring increasingly larger amounts of gas into its surroundings and, with part of this gas becoming ionised, interaction with solar wind particles intensified.”
As the comet approached perihelion, its closest point to the Sun in August 2015, the comet’s singing stopped. But then, as the comet’s activity began to decline, its plasma boundaries became unstable again and the magnetic field more chaotic once more. And in February 2016, the singing started up again.
Both releases of the singing comet’s sounds were produced with the help of musician and composer Manuel Senfft, who turned the plasma data into audible tracks. He told ESA’s Rosetta blog: “I was very fascinated by the symmetry of the magnetic field readings: first the oscillations, then chaos, then the magnetic field was gone… then chaos was back and then, in the end, also the oscillations.”
You can read more technical detail about how the singing comet’s sounds are produced in ESA’s Rosetta blog post.
The original recording of the singing comet, released in 2014. Original Data Credit: ESA/Rosetta/RPC/RPC-MAG. Sonification: Manuel Senfft (on behalf of the IGEP/TU Braunschweig).