SOLAR SYSTEM

Detailed explanation-1: -The corona is the outermost part of the Sun’s atmosphere. The corona is usually hidden by the bright light of the Sun’s surface. That makes it difficult to see without using special instruments. However, the corona can be seen during a total solar eclipse.

Detailed explanation-2: -The third layer of the sun’s atmosphere is the corona. Like the chromosphere, the sun’s corona can only be seen during a total solar eclipse (or with NASA’s Solar Dynamics Observatory (opens in new tab)).

Detailed explanation-3: -During solar eclipse the corona will be only visible. It is the outer most layer of the sun. The part we see the most of the time of the sun is the photosphere. But the corona is not visible during normal time.

Detailed explanation-4: -The inner layers are the Core, Radiative Zone and Convection Zone. The outer layers are the Photosphere, the Chromosphere, the Transition Region and the Corona. IRIS will focus its investigation on the Chromosphere and Transition Region.