Question

How did the lunar maria form?

Answer 1

Hint: Large, dark, basaltic plains on Earth's Moon which are the consequence of ancient volcanic eruptions is known as Lunar maria. They are about 2.5 billion years old.

Complete answer: Specimens of lunar rock and soil which are brought back by Apollo astronauts demonstrated that the maria comprises basalt which is formed due to surface lava flows that later get thickened.
-The maria basins were formed during a period of severe bombardment by asteroid-sized bodies. Such huge effects wrecked the Moon's lithosphere, enabling lava to fill the impact basins. It is the outcome of incremental erosion by micro-meteorites hitting the Moon.
-As of now, it is known as vast dark plains which are formed by basalts from volcanic outbursts. However, the lunar basalts are entirely devoid of water and contain limited volatile elements.

Note: -Crust is the largest layer inside the moon.
- Lunar highlands are the oldest lunar feature.
- The moon was discovered by Galileo Galilei.
- The first man to step on the moon was Neil Armstrong.