Large stretches of dark sand and dust scattered over the moon's surface?

Answer 1

The stretches of dark sand fooled early observers of the moon, who called them the mares, or seas. Some of the most prominent mares are Mare Tranquilitaties and Mare Imbrium.

Answer 2

The dark stretches of sand and dust on the moon's surface are called lunar maria, which are ancient basaltic plains formed by volcanic activity billions of years ago. The dark color comes from the dense basalt rock that formed from volcanic eruptions in the moon's early history. These maria cover about 16% of the moon's surface and provide a stark contrast to the lighter highlands that make up the rest of the moon.