Sinus Iridum

Sinus Iridum, Latin for "Bay of the Rainbow," is a prominent, curved feature on the Moon's surface. It’s a large, partly shaded crescent-shaped basin located on the northwestern edge of the larger Mare Imbrium (Sea of Rains). Formed by ancient volcanic activity and impact processes, it appears as a smooth, flat plain bordered by rugged, cratered highlands. Its name comes from the irregular bay-like shape resembling a rainbow’s curve. Sinus Iridum is notable for its striking appearance visible through telescopes and for being a popular landing site during lunar missions.