Some aspects of the Moon could be considered pretty boring and inhospitable: lack of atmosphere, no water or any surface volatiles whatsoever, a lifeless vacuum. On the plus side, it has some really interesting qualities: amazing views of Earth, including Earthrise and Earthset; 1/6th Earth gravity, which a trained athlete could use to perform 40 ft (12 m) high jumps, or a normal person could use to lift a small boulder; zero erosion, which means you could write your name in the ground and it would persist for millions of years unless removed by another astronaut (or future lunar colonist).
For the Moon to be colonized in the long term (which does seem likely) would require large bubbles of breathable air and contained ecosystems, but the majority of the Moon's surface is likely to remain distinctly lunar for a long time to come. What is there to see?
The geology of the Moon is broken into two main parts: the lunar highlands, which are light in appearance and very old, and the lunar maria ("seas"), dark plains filled with cooled lava. At one point, the entire Moon's surface was covered in a magma ocean, caused by the gigantic asteroid impact that kicked up the Earth's surface to form the satellite. It has since frozen solid, but the Moon had volcanoes for billions of years as it slowly cooled. These ancient volcanoes (some of which still exist, but never erupt) poured out tens of thousands of cubic kilometers of lava, which created the lunar maria we observe so easily from Earth. These maria are dated between 4.2 and 1.0 billion years ago, with most being created about 3.5 to 3.0 billion years ago. The maria are obviously younger than the surrounding highlands, due to their lower density of impact craters.
The Moon possesses about 30 major mountains, ranging in height from 0.5 km (0.3 mi) to 4.7 km (2.9 mi). Only seven mountains are taller than 3.0 km (1.8 mi). Mons Huygens is the tallest, and is a part of the Apenninus mountain range, where the Apollo 15 mission landed, widely considered the most scientifically successful lunar mission. No human being has yet summited this lunar peak, and the first person to do so will surely go down in history. In an interesting twist, the Moon's tallest mountain is not actually its highest point — this title goes to an area of highland on the far side of the Moon, a full 6.5 km (4 mi) further away from the lunar center than Mons Huygens.
Some of the greatest sites of the Moon are the numerous well-preserved and large craters. Without an atmosphere to shield it, the Moon is a sitting duck for asteroid impacts. Due to the near-zero erosion rate, these features are preserved in spectacular detail. The Moon has over a thousand craters greater than 10 km (6.2 mi) in diameter. The largest is the South Pole-Aitken basin. At roughly 2,500 km (1,550 mi) in diameter, the Aitken basin is the largest crater in the entire solar system. The only crater that even comes close is Hellas Planitia on Mars, with a diameter of 2,100 km (1,300 mi). The South Pole-Aitken basin is so large that its rim has a size similar to a mountain range.
By Michael Anissimov