Cratering Records in the Chang'e‐5 Mare Unit: Filling the “Age Gap” of the Lunar Crater Chronology and Preparation for Its Recalibration

Abstract

AbstractThe Moon is the cornerstone for dating planetary surfaces as it is the only planetary body that has been sampled multiple times from multiple places. The major deficiencies of the lunar crater chronology function are the somewhat limited number of calibration points and data gaps, especially in the ∼1–3 Ga segment. China's Chang'e‐5 mission recently returned samples from a young nearside mare, whose age is estimated to be in that age gap, providing a long‐awaited opportunity for recalibrating the lunar chronology. Here, we report a direct density measurement of impact craters ≥1 km in diameter of Chang'e‐5 mare unit, as (1.696 ± 0.221) × 10−3 km−2. The Chang'e‐5 mare deposits are estimated as ∼1.3–2.7 Ga old in various lunar chronologies, younger than all collected Apollo/Luna basalts. Accurate radio‐isotopic ages of Chang'e‐5 samples can be combined with our crater density measurement for a recalibration of lunar chronology.