The photosphere is the innermost layer of the Sun's atmosphere, and it's also the

A. atmospheric pressure of Jupiter.

B. invisible surface of the Sun.

C. nickname for the outer atmosphere of Earth.

D. visible surface of the Sun.

D. visible surface of the Sun.

The sun's atmosphere is composed of three main layers. 1. Photosphere - the lowest layer and closest in distance from the the sun's core. It has an average temperature of 5,800 degrees Kelvin. It usually appears granulated and bubbly, like a simmering pot of water. 2. Chromosphere - extends above the photosphere to about 2000 km. Its temperature is 4,500 - 10,000 degrees Kelvin. 3. Corona - outermost layer of the sun, extending several million kilometers outward from the chromosphere into space. The average temperature averages 2 million degrees Kelvin. It is thought the sun's magnetism is the reason that the corona is so hot.