🌙月球虹湾，月亮上的彩虹湾。
坐落于巨大雨海西北边缘，这片半圆形旷野跨度接近 250 公里，被崎岖峻峭的朱拉山脉环抱。
它并不是真正的海湾，而是远古撞击坑留下的遗迹。坑的南缘早已被雨海涌出的熔岩洪流淹没。
当月球晨昏线扫过此处，低角度阳光制造出极具冲击力的光影效果：朱拉山脉峰顶被阳光点亮，下方平原依旧沉在深邃阴影之中。
明暗交织的绝美景象，即便是家用小型天文望远镜，也能欣赏这处月球名景。

Gaze upon Sinus Iridum—the Bay of Rainbows—one of the Moon’s most breathtaking secrets. Nestled on the northwestern shore of the vast Mare Imbrium, this sweeping semicircular plain stretches nearly 250 kilometers across, cradled by the wild, jagged peaks of the Montes Jura.

What you’re seeing is no ordinary bay. It’s the ghost of an ancient impact crater, its southern wall long ago drowned beneath a flood of molten lava from the Imbrium basin. When the lunar terminator creeps near, the low-angled sunlight transforms the scene into pure drama: the Jura mountains leap into sharp relief, their summits blazing with light while the plain below still sleeps in deep shadow.

That dazzling dance of brilliance and darkness turns Sinus Iridum into a must-see spectacle for any skywatcher—and a pure thrill even through a simple backyard telescope.
🌙. By Damian Peach