NASA astronaut commander Eugene Cernan inside the lunar module on the Moon after his second moonwalk of the Apollo 17 mission. His spacesuit is covered with lunar dust.
On Earth, dust drifts to the floor where vacuum cleaners or a damp cloth remove it easily. In weightlessness, dust circulates freely and often irritates and inflames eyes and lungs.
In addition, dust on the Moon sticks to astronauts through static electricity and has sharp edges – all making it more likely that dust will enter astronauts’ lungs and do harm.