25.07.2018

Data from ESA (European Space Agency) and NASA’s Solar and Heliospheric Observatory (SOHO) has captured the dynamic movement of the Sun’s atmosphere for over 20 years. Today, we can hear the Sun’s movement — all of its waves, loops and eruptions — with our own ears.

This sound helps scientists study what can’t be observed with the naked eye.

“Waves are traveling and bouncing around inside the Sun, and if your eyes were sensitive enough they could actually see this,” said Alex Young, associate director for science in the Heliophysics Science Division at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

The Sun is not silent. The low, pulsing hum of our star's heartbeat allows scientists to peer inside, revealing huge rivers of solar material flowing around before their eyes — er, ears. NASA heliophysicist Alex Young explains how this simple sound connects us with the Sun and all the other stars in the universe. This piece features low frequency sounds of the Sun. For the best listening experience, listen to this story with headphones. Credits: Produced at NASA’s Goddard Space Flight Center by Katie Atkinson and Micheala Sosby

• Download "Sounds of the Sun" (68.5 MB WAV) | Transcript
• Additional multimedia for this story from NASA Goddard's Scientific Visualization Studio

Data from SOHO, sonified by the Stanford Experimental Physics Lab, captures the Sun’s natural vibrations and provides scientists with a concrete representation of its dynamic movements.

“We don’t have straightforward ways to look inside the Sun. We don’t have a microscope to zoom inside the Sun,” Young said. “So using a star or the Sun’s vibrations allows us to see inside of it.”

These are solar sounds generated from 40 days of the Solar and Heliospheric Observatory’s (SOHO) Michelson Doppler Imager (MDI) data and processed by A. Kosovichev. The procedure he used for generating these sounds was the following. He started with doppler velocity data, averaged over the solar disk, so that only modes of low angular degree (l = 0, 1, 2) remained. Subsequent processing removed the spacecraft motion effects, instrument tuning, and some spurious points. Then Kosovichev filtered the data at about 3 mHz to select clean sound waves (and not supergranulation and instrumental noise). Finally, he interpolated over the missing data and scaled the data (speeded it up a factor 42,000 to bring it into the audible human-hearing range (kHz)). For more audio files, visit the Stanford Experimental Physics Lab Solar Sounds page.​ Credits: A. Kosovichev, Stanford Experimental Physics Lab

• Download "Sun Sonification" (2.6 MB WAV)
• Additional multimedia for this story from NASA Goddard's Scientific Visualization Studio

These vibrations allow scientists to study a range of complex motions inside the Sun, from solar flares to coronal mass ejections.

“We can see huge rivers of solar material flowing around. We are finally starting to understand the layers of the Sun and the complexity,” Young said. “That simple sound is giving us a probe inside of a star. I think that’s a pretty cool thing.”

The sounds of the Sun are on display at the NASA Goddard Visitor Center in Greenbelt, Maryland. An immersive art installation, called Solarium, uses vivid imagery and sonification to transport listeners to the heart of our solar system.

Quelle: NASA