By the time it reaches Earth, solar wind is turbulent, gusty and unpredictable.
But it doesn’t start out that way.
As it emerges from the corona, the Sun’s upper atmosphere, the flow of charged particles is structured into defined rays.
However, details of how the particles transition from ray to wind have eluded scientists ever since the phenomenon was discovered in the 1950s.
Now, astronomers at NASA’s Goddard Space Flight Center believe they have the answer.
Using the Solar Terrestrial Relations Observatory, researchers have photographed solar wind emerging from the sun.
Craig DeForest, lead author of the study, describes the process: “As you go farther from the sun, the magnetic field strength drops faster than the pressure of the material does.
“Eventually, the material starts to act more like a gas, and less like a magnetically structured plasma.”
In a release, a NASA spokesperson draws a comparison to the way water shoots from a water pistol:
“First, the water is a smooth and unified stream, but it eventually breaks up into droplets, then smaller drops and eventually a fine, misty spray.”
The scientists’ astonishing images show the moment the plasma disintegrates into droplets.
Scientists had previously speculated that magnetic forces were at play at the edge of the corona, but it has never been observed.
Until now, the phenomenon, which takes place 20 million miles away, was too faint to process.
But in the latest study, scientists successfully used sophisticated computer processing to dim the appearance of bright stars.
In 2018, NASA will launch the Solar Probe Plus mission, a daring attempt to fly a probe into the corona, hoovering up even more data about solar wind.