To better understand the impact of the celestial body’s magnetic field on the solar system, scientists have created a "mini sun".
Physicists from the University of Wisconsin-Madison in United States mimicked solar winds and plasma ‘burps’ in a lab with the help of their 3 metre-wide creation, aptly dubbed the ‘Big Red Ball.’
They hope that their experiment will provide an “Earth-bound model for the future study of solar physics.”
“A lot of the open questions about the sun eventually come down to the magnetic field” because magnetic fields govern much of the sun’s activity, Therese Kucera, an astrophysicist at NASA’s Goddard Space Flight Center, was quoted as saying by Quantum Magazine.
“The solar wind is highly variable, but there are essentially two types: fast and slow,” said 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, are hoping that the Big Red Ball will allow them to study solar phenomena in three dimensions.
“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,” the university said in a press release.
The researchers stress that the Big Red Ball experiments are meant to complement and not replace satellite missions. For example, the Parker Solar Probe, launched in August 2018, is expected to reach and even dip below the Alfvén surface, where the magnetic field weakens and plasma breaks away from the sun, creating the solar wind.
This will provide direct measurements of solar wind never obtained before.
“Our work shows that laboratory experiments can also get at the fundamental physics of these processes,” Peterson says. “And because 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 solar wind, you can do that here.”