This dramatic Sun explosion could unlock the secrets of fusion

A never-before-seen magnetic explosion has confirmed a long-suspected theory about our Sun, not to mention creating a dramatic light show spotted for the first time. NASA scientists at the Solar Dynamics Observatory caught the moment a vast loop of superheated material erupted from the surface of the Sun on the SDO's sensors, then blossomed into a magnetic explosion.

The Sun is hardly a stable subject for observation by the SDO team, frequently seeing huge eruptions of material, swinging magnetic fields, and more. However while NASA and other scientists have seen magnetic field lines explosively snap and realign before, this is the first time it has been caught being triggered by an eruption.

It's known as forced reconnection, and researchers were theorizing about its existence as long as 15 years ago. However unlike spontaneous reconnection, which has been viewed before, forced reconnection has proved stubborn to capture on sensors. That's primarily because it demands a rare sequence of coincidental events in order to take place.

Unlike spontaneous reconnection, which needs certain conditions regarding electric current conduction in order to take place, forced reconnection could potentially happen across more of the Sun's surface. However it won't be triggered unless there is an eruption: that squeezes the plasma and the magnetic fields, until they reconnect. By watching the Sun with the SDO's precise sensors, focusing on the wavelength of light where particles are heated to 1-2 million kelvins (1.8-3.6 million F), the researchers could track what was happening in the solar corona.

It took around an hour for the eruption, known as a prominence, to fall back into the photosphere. As it fell, however, it met with the snarled magnetic field lines. The plasma rocketed up in heat, seemingly drawing energy from the corona.

While it makes for an impressive light show, scientists are also excited about the observation's potential impact on other areas of research. For a start, it could pave the way to new understanding of solar weather, particularly the way that solar radiation impacts satellites orbiting Earth and, at times, damaging them.

Beyond that, the same processes that magnetic reconnection follow could be used to recreate the system in the lab. That might allow researchers to control fusion and plasma in a more stable way, and eventually unlock new sources of energy and more.

"This was the first observation of an external driver of magnetic reconnection," Abhishek Srivastava, solar scientist at Indian Institute of Technology (BHU), in Varanasi, India, said of the findings. "This could be very useful for understanding other systems. For example, Earth's and planetary magnetospheres, other magnetized plasma sources, including experiments at laboratory scales where plasma is highly diffusive and very hard to control."