On Earth we have we have winds that blow particles around and water that erodes and breaks down rock and other hard materials. These two elements work in conjunction to wear down particles over millions of years into an almost spherical shape. For example if you were to look at sand from a beach on Earth under a microscope you would find the grains to be predominantly smooth and round. This process is called erosion.
The Moon, however, has no atmosphere, as such it has no wind and no oceans, rivers or rain. It has none of the tools that Earth uses to grind away at the rough edges of particles to make them smooth like our sand and soil. As a result of this, the dust that covers the surface of the Moon is razor-sharp, made up of microscopic stone and powered glass from millions of years of meteorites slamming into the surface at high velocities. The particles that form from the shards that break off from these impacts are far from spherical, they have jagged sharp angles, with microscopic hooks that jut out in all directions and with nothing to change them they remain this way forever…or until a man in a spacesuit decides to step on the surface and disturb them.
During the Apollo missions to the moon between 1969 and 1972, 12 astronauts have stepped foot on the surface of the moon and the main issue that the astronauts pointed out was “Dust, dust, dust”, Harrison Schmitt of Apollo 17 was quoted as saying “Dust is the number 1 environmental problem on the moon”.
But what were the problems?
The microscopic particles (only a few microns wide) would get into the joints of the space suits and would lock in using their jagged edges and make it difficult to move their limbs, the dust was also small enough to make its way inside attachments and seals on their equipment causing further problems. The graphite-black dust would be so thick, the white suits of the astronauts would look like they had been “playing in a coal bin”, if they reached up to wipe their visors the dust would scratch away the protective surface layers. The black dust would cause further problems as the white material was chosen to reflect the Sun’s light but the thick, dark dust would absorb the sunlight, overheating their life support systems. The dust also was so abrasive that it wore through 3 layers of Kevlar-like material (similar to that of which modern bullet proof vests consist of) on one astronauts boots.
Once the astronauts had left the surface and returned to their lunar lander the problems with the dust didn’t stop, the small particles would enter the air and could be breathed in to the astronauts lungs, the dust particles are small and sharp enough to penetrate deep within lung tissues causing a slew of respiratory problems. The particles would also cause damage to the skin and eyes, if you rubbed your eyes with your hands the particles would scratch and dig in to your corneas causing a lot of pain.