The lunar maria are best described as which of the following?

The lunar maria are best described as which of the following?

• A. Highlands
• B. Maria
• C. Craters
• D. Rilles

Answer: (B)

Lunar maria are large, dark, smooth plains on the Moon formed when ancient basaltic lava flowed up and filled huge impact basins. This volcanic flooding created broad flat areas that contrast with the lighter, heavily cratered highlands, giving maria their distinctive appearance. They are not highlands, which are the bright and rugged regions; not craters, which are impact holes; and not rilles, which are channel-like features. The name maria (seas) reflects the old idea of seas on the Moon, though they contain no water. So the best description is basaltic lava plains created by ancient volcanic activity.

Lunar maria are large, dark, smooth plains on the Moon formed when ancient basaltic lava flowed up and filled huge impact basins. This volcanic flooding created broad flat areas that contrast with the lighter, heavily cratered highlands, giving maria their distinctive appearance. They are not highlands, which are the bright and rugged regions; not craters, which are impact holes; and not rilles, which are channel-like features. The name maria (seas) reflects the old idea of seas on the Moon, though they contain no water. So the best description is basaltic lava plains created by ancient volcanic activity.