EEPS Colloquium: Nicole Nie

Isotopic Insights into Moon Formation and Surface Evolution

The Moon is significantly depleted in moderately volatile elements (MVEs) relative to Earth, a signature commonly linked to its energetic origin involving a giant impact and subsequent global magma ocean. While most volatile loss likely occurred during this early stage, continued loss from the lunar surface through space weathering has further modified the Moon’s volatile inventory. Isotopic compositions of MVEs provide key constraints on both the early high-temperature depletion and the later surface weathering processes.

In this presentation, I will examine MVE isotopic variations in both igneous samples and lunar soils to assess the mechanisms of volatile loss. Isotopic data from lunar basalts help distinguish among competing models for early lunar volatile depletion and support an evaporative loss scenario in the proto-lunar disk. In addition, isotopic enrichments in lunar soils reflect ongoing space weathering, indicating that micrometeorite impacts are a dominant process transferring surface atoms into the transient lunar exosphere and ultimately into space.

EEPS Colloquia are made possible by the William C. Ferguson Fund