What is the name of the outermost part of the sun's surface?

What is the name of the outermost part of the sun's surface?

• A. Chromosphere
• B. Photosphere
• C. Corona
• D. Exosphere

Answer: (C)

The outermost part of the sun's surface is called the corona. This region extends millions of kilometers into space and is visible during a total solar eclipse as a halo of plasma. The corona is much hotter than the layers beneath it, such as the photosphere and chromosphere, with temperatures reaching up to several million degrees Celsius. This phenomenon is central to many astrophysical processes, including solar wind production and the behavior of solar magnetic fields.

While the photosphere is often considered the visible surface of the sun and is where most of the sun's light is emitted, it is not the outermost layer. The chromosphere lies above the photosphere and is a less significant layer in terms of distance from the sun's center. The exosphere typically refers to the thin, outermost layer of a planetary atmosphere, which is not applicable to the sun. Thus, understanding the corona’s role and characteristics distinguishes it as the correct answer to the question regarding the sun’s outermost surface.