What is the largest maria on the moon called?
The dark areas on the Moon's surface are called maria. The maria cover only 15 percent of the lunar surface. The Maria are lower in altitude than the Highlands, but there is no water on the Moon so they are not literally seas. Mare Imbrium or the Sea of Showers is the largest mare at 700 miles in diameter.
The dark flat areas on the moon's surface are called Maria. The singular form of Maria is mare, which means sea. Although there are no seas on the moon, this is the term used to describe these darker areas. Approximately 16 percent of the moon' surface is covered with Maria. Most of these Maria are visible on the near-side of the moon.