Quiet Sun through Cloud

I got a few snatched shots of the Sun before the cloud closed in solidly and it started to rain. The Sun is very quiet at the moment, AR1777 is just visible. A new solar telescope is being launched today, IRIS, standing for Interface Region Imaging Spectrograph. This will be like a microscope viewing the Sun, looking at a very small area but with a resolution able to make out features only 150 miles across.
IRIS will pay special attention to a thin layer of the sun's atmosphere called the "interface region" where most of the sun's ultraviolet emission is generated. Researchers are keen to study this layer because it is likely to be the energy source for the sun's mysteriously-hot outer corona. The 'surface' of the Sun that we see is at a temperature of about 5,000C, as the atmosphere gets less dense the further away from this surface the temperature dramatically rises to 1,000,000C or more! Nobody really knows why as of yet. Above the visible surface, the photosphere, is a much less dense layer called the chromosphere about 2,500km deep; beyond that is the very sparse but ultra-hot corona. The region between the chromosphere and the corona is the interface region and this will be the focus of study for IRIS.
Sorry for the wordy entry, but it is very exciting to anticipate what new knowledge will be thrown up!