Although it’s the closest star to Earth, the Sun has been very good at keeping some of its secrets. Among them, there’s the cause of the eruptions on the surface of the Sun. A group of researchers from Durham University and NASA’s Goddard Space Flight Center have now proposed a mechanism to explain both the biggest and smallest eruptions.
According to their study, published in Nature, small bursts of plasma known as coronal jets are produced by the same phenomenon believed to cause the coronal mass ejections – gigantic blasts of plasma that are propelled into interplanetary space.
The culprit is a phenomenon called magnetic reconnection. Plasma is charged and the magnetic field of the Sun moves it around. Once in a while, the magnetic field lines break apart and then join back again, and this allows plasma to suddenly and explosively jump out. The strength and structure of the magnetic field determine the size of the eruption.
“It was previously thought that there were different drivers for the varying scales of eruptions from the Sun, but our research provides a theoretical universal model for this activity, which is very exciting,” lead author Dr Peter Wyper, from Durham University, said in a statement.
Understanding these eruptions as a unified concept will allow solar physicists to work out how they start, which will help researchers predict them. This bears consequences beyond the Sun itself, as the biggest explosions can launch particles that have destructive effects on orbiting satellites and even reach Earth.
“A greater understanding of solar eruptions at all scales could ultimately help in better predicting the Sun's activity," Wyper added. "Large-scale coronal mass ejections, where huge amounts of solar plasma, radiation, and high-energy particles are being released, can influence the space around them, including the space near to Earth."
“They can interfere with satellite communications, for example, so it is beneficial for us to be able to understand and monitor this activity.”
Confirming this finding will require more detailed observations of the solar magnetism. Upcoming missions like Solar Probe Plus and the Solar Orbiter will hopefully provide the data to reveal a few more mysteries of our Sun.