As recently as December 2013, nanoflares were discovered in the corona of the sun by the Extreme Ultraviolet Normal Incidence Spectrograph (Eunis) mission. What this discovery led to was the discovery of why the sun’s corona emits such high temperatures. The star’s (sun’s) surface generally measures about 10,300 degrees Farenheit while the corona, the atmosphere of the sun, measures at a few million degrees Farenheit.

Normally, heat wanes when removed from the heat source. However, in the case of the corona of the sun, burns hotter. For many years, astronomers have been puzzled by the the difference being recorded up to 300 times hotter than the surface.

It was found there are smaller explosive events erupting from the sun’ surface and one-billionth of the energy of a regular solar flare. These events pack the wallop of a 10 megaton hydrogen bomb and temperatures as hot as 18 million degrees Farenheit.

The findings were announced on April 28, 2015 at the first Triennial Earth-Sun Summit (TESS) which is comprised of heliophysicists and held in Indianapolis, Indiana. At the same summit, another presentation was given upholding the existence of nanoflares.

The most compelling evidence was that collected by the EUNIS mission providing direct physical information.  To collect data the spacecraft used infra-red imaging to record wavelengths of a spectrum of light and the short-wavelength coming from the surface of the sun.

In addition to the findings from the spacecraft, the Nuclear Spectroscopic Telescope Array (NuSTAR) has also recorded the sun’s x-rays showing the existence of the tiny flares erupting. NuStar is generally used to detect black holes and the presence of distant stars, and, in this case, study the bright light of our sun.