The Sun is not silent

The sounds of the sun.

The Sun is not silent

Sun, the hot ball of glowing gases at the heart of our solar system. Most of the gas — 91 percent — is hydrogen. It is converted into energy in the sun’s core. The energy moves outward through the interior layers, into the sun’s atmosphere, and is released into the solar system as heat and light.

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 the 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

This giant ball of plasma is peppered with sunspots, exploding with flares and spewing out huge clouds of charged particles into space in the form of coronal mass ejections.

Now, a new data captured by ESA (European Space Agency) and NASA’s Solar and Heliospheric Observatory (SOHO), suggests that the sun is not silent. The SOHO has captured the dynamic movement of the Sun’s atmosphere for over 20 years. It also has captured the sound of Sun’s movement — all of its waves, loops, and eruptions.

According to scientists, the data could help them study what can’t be observed with the naked eye.

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

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

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

“We can see huge rivers of solar material flowing around. We are finally starting to understand the layers of the Sun and the complexity. 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.