Nasa has found mysterious 'magnetic braids' near to the surface of the Sun.
The strange super-hot shapes in the outer atmosphere of our star might explain why its six million-degree corona is so hot compared to its surface.
The discovery was made by the High Resolution Coronal Imager, which is a 9.5-inch telescope in space dedicated to searching the sun for signs of impending space weather and examining its structure.
It was launched in July, and took 165 photographs in high resolution before returning to Earth via parachute.
The surface of the Sun is hot - 6,125 degrees Celsius - but the corona above its surface is a thousand times hotter.
Scientists have beens attempting to understand why this is true for some time. One theory suggests that magnetic 'waves' beneath the Sun's surface could boost the temperature by about 1.5 million C, but even that isn't enough.
"Scientists have tried for decades to understand how the sun's dynamic atmosphere is heated to millions of degrees," said Hi-C principal investigator Jonathan Cirtain, in a statement.
"Because of the level of solar activity, we were able to clearly focus on an active sunspot, and obtain some remarkable images. Seeing this for the first time is a major advance in understanding how our sun continuously generates the vast amount of energy needed to heat its atmosphere."
The new pictures of 'braids' - literally intertwined strands of magnetic fields according to Cirtain speaking to Space.com - might provide an answer.
Above: Nasa pictures 'braids' of magnetic energy
Scientists say that they could generate massive amounts of heat through a complicated process involving fields that become so curved they become unstable, releasing massive amounts of energy.
The findings of the Nasa team were published in Nature on 24 January, but if you want to go into specifics and don't have a degree in astrophysics, we suggest Space.com's neat summary.
The observations could lead to better forecasting of space weather, where massive amounts of radiation and solar material are thrown off and can interfere with satellites and transmissions here on Earth.
"The Hi-C observations are part of a technology demonstration that will enable a future generation of telescopes to solve the fundamental questions concerning the heating of the solar atmosphere and the origins of space weather, "said Jeffrey Newmark, sounding rocket program scientist at Nasa, in a statement.
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