The Sun's Hot Secret: Researchers Recreate a Phenomenon Considered a Mystery

Researchers from China have recreated in a laboratory a physical process that may explain why the Sun's outer atmosphere is hundreds of times hotter than its surface. The experiment, published in Physical Review Letters, demonstrated how magnetic reconnection in plasma heats electrons to a temperature of nearly 820,000 degrees Celsius.

Researchers from China have successfully recreated in a laboratory a process that may explain why the Sun's outer atmosphere (the corona) is hundreds of times hotter than its surface. In an experiment conducted at the China Institute of Atomic Energy and Beijing Normal University, scientists used four powerful laser beams fired at a plastic target with a wavy surface. The pulses turned the material into plasma, creating magnetic fields in opposite directions that reconnected and heated the plasma to a temperature of nearly 820,000 degrees Celsius—twice as much as with a flat surface. The findings, published in the journal Physical Review Letters, support the theory that countless tiny eruptions called nanoflares heat the corona. The experiment provides a tool to study these conditions in a controlled environment, advancing the understanding of extreme physical phenomena in the cosmos.