Which of the Sun's layers is seen as the Sun's visible surface?

• A. Corona
• B. Photosphere
• C. Chromosphere
• D. Radiative zone

Answer: (B)

The visible surface of the Sun in ordinary light is the photosphere. It’s the lowest part of the Sun’s atmosphere from which most of the Sun’s visible light escapes, so it forms the disk you see. You can even notice grainy textures called granulation, caused by convection beneath the surface. The corona is the outer atmosphere and is visible only during eclipses or with special instruments, not as the Sun’s surface in normal viewing. The chromosphere lies above the photosphere and glows in specific wavelengths, not as the bright disk we normally see. The radiative zone is deep inside, where energy moves outward by radiation, not from the surface. So, the photosphere is the Sun’s visible surface.