A new study by physicists mimicked solar winds in the lab, confirming how they develop and providing an Earth-bound model for the future study of solar physics.

A new study by University of Wisconsin-Madison physicists mimicked solar winds in the lab, confirming how they develop and providing an Earth-bound model for the future study of solar physics.

Our sun is essentially a big ball of hot plasma — an energetic state of matter made up of ionized gas. As the sun spins, the plasma spins along, too. This plasma movement in the core of the sun produces a magnetic field that fills the solar atmosphere. At some distance from the sun’s surface, known as the Alfven surface, this magnetic field weakens and plasma breaks away from the sun, creating the solar wind.

«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 and lead author of the study published online July 29 in Nature Physics. «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.»

Peterson and his colleagues, including physics professor Cary Forest, may not have direct access to the big plasma ball of the sun, but they do have access to the next best thing: the Big Red Ball.

The Big Red Ball is a three-meter-wide hollow sphere, with a strong magnet at its center and various probes inside. The researchers pump helium gas in, ionize it to create a plasma, and then apply an electric current that, along with the magnetic field, stirs the plasma, creating a near-perfect mimic of the spinning plasma and electromagnetic fields of the sun.

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Materials provided by University of Wisconsin-Madison. Original written by Sarah Perdue. Note: Content may be edited for style and length.