Final answer:
The visibility of the solar corona is limited by the brightness of the Sun's photosphere, which emits a large amount of light. This makes it difficult to observe the fainter outer layers of the Sun's atmosphere, including the corona, which is composed of low-density hot gas.
Step-by-step explanation:
The visibility of the solar corona is limited by the brightness of the Sun's photosphere.
The photosphere is the visible surface of the Sun and emits a large amount of light, which makes it difficult to observe the fainter outer layers of the Sun's atmosphere, including the corona.
The corona is the outermost part of the Sun's atmosphere and is composed of low-density hot gas.