Astronomy Practice Exam

The outermost region of the Sun’s atmosphere is called the corona. This layer is primarily composed of plasma and is characterized by its high temperatures, which can reach up to several million degrees Celsius. The corona extends millions of kilometers into space and is visible during a total solar eclipse as a halo of light surrounding the Sun. This region plays a significant role in solar phenomena such as solar wind, which consists of charged particles ejected from the Sun and influences space weather. The corona is distinct from the inner layers of the Sun’s atmosphere, such as the photosphere, which is the visible surface of the Sun, and the core, where nuclear fusion occurs. Understanding the structure and behavior of the corona is essential for studying solar activity and its effects on the solar system.