Airdate: Jan 15, 2004
Scientist: Craig DeForest
Sounds of the Sun
The sun is in constant turbulent motion, like the contents of a fiery cauldron, causing it to ring like an enormous bell.
ambience: Solar oscillations
Like the contents of a fiery cauldron, the sun is in constant turbulent motion. As a result it's oscillating, ringing like an enormous bell. Right now we're listening to a time lapse version of the sounds of the sun's vibrations. I'm Jim Metzner, and this is the Pulse of the Planet.
At nearly 11,000 degrees Fahrenheit, the surface of the sun is decidedly off limits to human exploration. So, NASA scientists launched SOHO, the Solar and Heliospheric Observatory, a spacecraft which is now orbiting the sun about a million miles away from Earth. With the help of detectors onboard SOHO, scientists are able to monitor the sound waves which originate from the sun.
"What we're playing for you is a speeded up version of the sound waves that we're detecting on the surface of the Sun. What you're hearing here is the Sun itself oscillating in and out in a kind of breathing motion once every five minutes. And we've sped that up to make it audible."
Craig DeForest is a Solar Physicist at Stanford University and a researcher with the SOHO team.
"The sounds that are resonating inside the Sun are created by turbulent motions on the surface of the Sun. The entire surface is heated from below by the fusion going on inside, and the outer layers of the Sun are turning over and boiling, kind of like a pot full of oatmeal on the boil. Hot material from down inside the Sun is constantly rising to the surface, cooling off and then sinking down inside and that turbulent motion is what stimulates these sound waves."
As a result of studying these sounds, scientists have been able to identify jet streams inside the sun. These rivers of hot gasses travel at about 60 miles an hour, producing a subtle but identifiable musical shift inside the solar symphony.
Pulse of the Planet is presented by the National Science Foundation.