Moon dust is made of razor-sharp glass shards
On Earth, wind and water tumble rock fragments into smooth, rounded grains of sand. The Moon has no atmosphere or liquid water to erode anything. Instead, billions of years of micrometeorite bombardment continually pulverized lunar rocks and melted mineral grains into microscopic, jagged glass beads. Apollo astronauts discovered this regolith dust was relentlessly abrasive, clinging to suits via static electricity, wearing through heavy fabric layers, and irritating their eyes and lungs.
The Anatomy of a Violent Landscape
On Earth, natural forces work continuously to soften the edges of the physical world. Flowing rivers, crashing ocean surf, and winds carrying moisture roll broken mineral fragments against one another across millions of years. This mechanical and chemical weathering grinds down sharp facets, producing the smooth, rounded grains that make up ordinary river gravel and beach sand. Oxygen and water vapor also chemically alter exposed minerals, neutralizing reactive chemical bonds on freshly exposed rock faces and blunting their microscopic hazards.
The Moon possesses neither an atmosphere nor liquid water, leaving its geology entirely devoid of natural smoothing mechanisms. Its surface is dominated by lunar regolith, an unconsolidated layer of debris that blankets the bedrock. Without an atmospheric shield to burn up incoming space debris, the lunar surface has absorbed billions of years of uninterrupted micrometeorite impacts. These microscopic projectiles slam into the crust at hypervelocity speeds, shattering basalt, anorthosite, and primary minerals like plagioclase feldspar, pyroxene, and olivine into fine, fractured remnants.
When high-speed micrometeorites strike, the extreme localized energy flash-melts portions of the lunar minerals. This molten rock rapidly cools into glass droplets and welds together existing rock fragments, creating porous, jagged structures known as agglutinates. Rather than rounding out the debris, this violent thermal and mechanical process creates a microscopic landscape of jagged splinters, hollow shards, and razor-sharp silicate glass edges that remain indefinitely sharp.