Mystery of the sun’s mind-bogglingly hot atmosphere may finally be solved

A hot mystery on the sun may be close to being solved.

For decades, scientists have been trying to understand why the sun’s outer atmosphere is so much hotter than its surface, despite being farther from the core. Whereas the surface, or photosphere, is millions of degrees Fahrenheit, the outer atmosphere is only about 10,000 F (5,500 C).

Now, thanks to observations from a new high-resolution telescope, scientists have finally spotted elusive “magnetic waves” in the sun’s atmosphere that may be responsible for much of the corona’s incredible heating. The findings were published Oct. 24 in the journal Nature Astronomy.

New data from the National Science Foundation’s Daniel K. Inouye Solar Telescope (DKIST) in Hawaii — the largest ground-based solar telescope ever built — is helping scientists learn how the sun’s energy is transported through its atmosphere.

A solar mystery

Researchers previously noted the extreme temperature of the sun’s corona, as well as the supercharged flow of heated gas, called the solar wind, which streams from the sun at more than 1 million mph (1.6 million km/h), said Richard Morton, a solar physicist and professor at Northumbria University in the U.K. who led the research, told Live Science in an email.

Both processes need energy, and scientists assumed rolling convection at the sun’s surface generated the requisite fuel. But complications arose during the first studies of this decades ago.

“It is unclear how this [energy] gets transferred into the atmosphere and solar wind, and how the energy is converted to heat and momentum,” Morton said.

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