Scientists at the University of Wisconsin – Madison have created an artificial Sun to study the solar winds that that can interfere with satellites, create auroras, and power solar sails.
While the Sun looms large in our sky, the star at the center of our solar system still contains many mysteries. One such unknown is how solar winds—streams of charged particles jettisoned from the Sun’s corona—escape the crushing gravity of the star.
To answer this question, researchers in Wisconsin have built what they describe as a “Big Red Ball”, a nearly 10-foot-wide hollow sphere that creates an artificial sun within its core.
But reaching conditions that mimic the Sun isn’t an easy task and to achieve this, engineers have to do quite a lot of highly energetic work. First, helium is pumped into the Big Red Ball’s center. Once filled, the helium is then ionized forcing the element to shed its electrons in an effort to transition into a plasma state. After the helium has phased into the fourth state of matter, an electrical current is applied, and the cosmological soup begins to resemble an artificial sun that spin off solar winds.
“The solar wind is highly variable, but there are essentially two types: fast and slow,” explains Ethan Peterson, a graduate student in the department of physics at UW–Madison. “Satellite missions have documented pretty well where the fast wind comes from, so we were trying to study specifically how the slow solar wind is generated and how it evolves as it travels toward Earth."
With their new tools, researchers at Wisconsin will be able to simulate the electromagnetic phenomenon that surrounds the Sun and extends across the solar system— the solar wind. Not only do these winds create brilliant visual displays like our planet’s polar auroras but they energize matter that extends to the Oort Cloud and beyond.
Fortunately, physicists in Madison aren’t being stingy with their new tool, opening it up for outside research.
“[B]ecause the Big Red Ball is now funded as a National User Facility, it says to the science community: If you want to study the physics of solarwind, you can do that here,” Peterson beamed.