Lunar Maria: Volcanic Basins on the Moon

What are the dark spots on the moon?

One of the main things you notice on the moon is that it has bright and dark areas across the surface.

Everybody’s familiar with the man on the moon, right?

The dark areas are known as “mare” (or maria) which is the Latin word for “seas”. They’re called maria because early scientists believed they could see oceans on the moon. But the dark stretches on the surface of the moon were not oceans at all.

What the “maria” actually turned out to be were volcanic basins. They were created from the aftermath from ancient impacts billions of years ago. After the impacts, the craters filled with lava. Eventually, the lava cooled. These flat flood basalts formed smooth lunar maria.

The Sea of Tranquility Maria

One of the most famous maria is the Sea of Tranquility.

This was the landing site chosen by Apollo-11 in part because it was fairly smooth and level.

Apollo-11 is world renowned because it gave mankind its first ever walk on the moon.

Not only for a landing site, it made an easy trek for Neil Armstrong.