Space Weathering: Clear with a Chance of Solar Wind and Micrometeoroid Showers

Airless planetary surfaces are continually modified by energetic solar wind ions and hypervelocity dust impacts, a phenomenon known as space weathering. Models for space weathering are built on the foundation of returned sample analysis, but understanding these changes to surface regolith is also key to interpreting spacecraft remote sensing observations. Lunar samples first revealed the myriad microstructural and chemical effects of space weathering, and Genesis then provided important context for the mechanism of solar wind modifying these surfaces. Sample return from near-Earth asteroids has further transformed our understanding of how diverse bodies experience space weathering. The analysis of samples from these mineralogically diverse sources has contributed to a model for space weathering and planetary surface evolution across the Solar System.