GEOLOGY

Detailed explanation-1: -The lunar maria (or plains), which were formed between 3.1 and 3.9 billion years ago, are the youngest geologic units on the lunar surface, except for more recent impact craters. The release of heat from large impacts caused extensive melting and extrusion of basaltic lavas on the moon.

Detailed explanation-2: -It is divided into light areas called the Lunar Highlands and darker areas called Maria (literally, “seas"; the singular is Mare).

Detailed explanation-3: -Lunar lava plains cover large swaths of the Moon’s surface and consist mainly of voluminous basaltic flows. They contain a number of volcanic features related to the cooling of lava, including lava tubes, rilles and wrinkle ridges.

Detailed explanation-4: -Apollo astronauts discovered that these regions are smooth, low-lying plains with relatively few craters. Maria get their color from a type of rock (called basalts) similar to the dark colored rocks formed by lava from volcanoes here on Earth.

Detailed explanation-5: -According to the astronauts the surface of the Moon is rough, dusty, barren and irregular. It has large craters on its surface and many steep and high mountains.