Explore the Moon's major surface features, including impact craters, dark maria, highlands and the clues they preserve about lunar history.
Why the Moon looks so heavily cratered
The Moon has no thick atmosphere, oceans, or active weather to erase most impact scars. As a result, craters can remain visible for billions of years, preserving a record of collisions that shaped the inner Solar System.
What lunar maria really are
The dark regions visible from Earth are called maria, the Latin word for seas. They are not water. They are broad plains of dark volcanic rock created when ancient lava filled large impact basins.
Bright highlands and old terrain
The lighter areas are mainly ancient highlands. These regions are generally older and more heavily cratered than the maria, which makes them especially useful for understanding the Moon's early geological history.
Mountains without plate tectonics
Many lunar mountain ranges were formed by enormous impacts rather than Earth-like plate tectonics. When giant objects struck the Moon, they lifted and fractured the surrounding crust.
What the surface tells scientists
By studying crater counts, rock samples, and spacecraft images, scientists can reconstruct a timeline of lunar volcanism and impacts. The Moon acts like a natural archive because its surface changes relatively slowly.
What to look for from Earth
Even a small telescope can reveal major craters, mountain shadows, and the contrast between maria and highlands. The best detail often appears near the terminator, the line dividing lunar day and night.
Continue with our related Neela Asman guide. For broader science background, visit NASA Science.