Scientists have created a mini sun in the lab to study the original one
The Big Red Ball is a three-meter-wide hollow sphere, has a strong magnet at its centre and is filled with helium.
Our sun makes its influence on objects present in our solar system through the solar wind. These solar winds that erupt on the surface of the sun also disrupt the function of Earth's satellites.
It’s difficult to get close to the Sun's surface, so physicists from University of Wisconsin–Madison have created a Big Red Ball or mini-sun that mimics solar winds in the lab.
The Big Red Ball is a three-meter-wide hollow sphere. It has a strong magnet at its centre. Researchers pumped helium gas inside the plasma and ionised it to create a plasma. They applied electric current along with a magnetic field to stir the plasma. This then acts like the sun that rotates with plasma and electromagnetic field around it.
Now that the researchers have created a mini-sun on earth, they can take measurements at any point inside the ball. The study will allow them to discover more about solar phenomena.
The researchers have already identified the source of the periodic ejection of plasma that is responsible for bringing the solar wind. The scientists also studied the magnetic field and speed of the plasma.
How solar winds are created:
“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 . “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.
They mapped a region where the plasma was moving fast enough to escape the weak magnetic field. The magnetic field was found to be weak in that region that leads to the break-off and radical ejection of the plasma causing the solar wind.
“These ejections are observed by satellites, but no one knows what drives them,” Peterson says. “We ended up seeing very similar burps in our experiment, and identified how they develop.”
Researchers say that the Earth-bound experiment complements satellite missions to the sun, but don't replace them.
They quoted the example of the Parker Solar Probe, launched in August 2018. The mission by NASA is expected to reach and even dip below the Alfvén surface. Alfvén surface is a region near the sun's surface where the magnetic field weakens and plasma breaks away from the surface to create solar wind. It will provide direct measurements of solar wind never obtained before.