The chromosphere is the second of the three main layers in the Sun's atmosphere and is roughly 3,000 to 5,000 kilometers deep. Its rosy red color is only apparent during eclipses. The chromosphere sits just above the photosphere and below the solar transition region.

What does chromosphere mean in English?

: the region of the atmosphere of a star (such as the sun) between the star's photosphere and its corona.

What is the chromosphere in the sun?

The lower region of the Sun's atmosphere is called the chromosphere. Its name comes from the Greek root chroma (meaning color), for it appears bright red when viewed during a solar eclipse. The chromosphere extends for about 2,000 kilometers (1,200 miles) above the visible surface of the Sun.