Giordano Bruno: the Young and the Restless

Introduction: Giordano Bruno (GB) crater is among the youngest large lunar impact craters (22 km diameter at 36°N, 103°E (Fig. 1)). Its crisp morphology, extensive ray system, and spectral properties imply a young age (<<1 by). Spectral data [1, 2] indicate the ray material is immature having an optical maturity index, calculated from the Clementine 950/750 nm ratio [2, 3] of ~0.27. It was suggested by [4] that GB might have been historic, observed to form in 1178. The possibility that such a large impact could be of historic age makes it an important target. Additionally, because of its youth, the details of impact cratering morphology are preserved in exquisite detail. Morota et al. [5] reported an age of 1-10 Ma based on crater counts made with Terrain Camera images from the Kaguya mission. Here, we report an overall geologic analysis and crater counts derived from Lunar Reconnaissance Orbiter Camera (LROC) images and Diviner Lunar Radiometer Experiment data.