This chapter describes the planet Rāhu, which is 10,000 yojanas (80,000 miles) below the sun, and it also describes Atala and the other lower planetary systems. Rāhu is situated below the sun and moon. It is between these two planets and the earth. When Rāhu conceals the sun and moon, eclipses occur, either total or partial, depending on whether Rāhu moves in a straight or curving way.