mikrometeoroider

Mikrometeoroider, or micrometeoroids, are small particles found throughout the solar system. They typically range from about 10 micrometers to 1 millimeter in diameter and are composed of rock, metal, or a mixture of both. Their origins include dust released by the erosion and breakup of comets, collisions among asteroids, and other interplanetary dust. Traveling at high velocities, micrometeoroids collide with planets and spacecraft at speeds from roughly 11 to 70 kilometers per second, depending on orbital geometry. These high speeds make even tiny particles capable of causing damage on impact.

Because of their small size, micrometeoroids are challenging to detect before impact, but their cumulative effects are a concern for spacecraft. Hypervelocity impacts can create craters, eject material, and degrade surfaces such as solar panels or instruments. To mitigate risk, spacecraft employ shielding designs such as Whipple shields, multi-layer insulation, and careful trajectory planning in high-flux regions. Material choice and engineering models aim to limit penetration and reduce long-term erosion.

Scientists study micrometeoroids with dust detectors and impact sensors, and by examining micro-craters on exposed surfaces from missions such as LDEF (Long Duration Exposure Facility). The distribution of micrometeoroids varies with solar distance and orbital path, and Earth experiences temporary increases in flux when crossing debris streams from comets, causing meteor showers. In addition to posing a hazard, micrometeoroids contribute to the zodiacal dust cloud and offer clues about primitive solar system material. On Earth, the smallest particles burn up in the atmosphere as meteors, while larger ones may reach the surface as meteorites.