Premium
Geologically Old but Freshly Exposed Rock Fragments Encountered by Yutu‐2 Rover
Author(s) -
Gou Sheng,
Yue Zongyu,
Di Kaichang,
Bugiolacchi Roberto,
Wan Wenhui,
Yang Meiping,
Ye Lejia
Publication year - 2021
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
eISSN - 2169-9100
pISSN - 2169-9097
DOI - 10.1029/2020je006565
Subject(s) - impact crater , ejecta , geology , lunar craters , astrobiology , geochemistry , mineralogy , physics , astrophysics , supernova
During the exploration traverse of the Von Kármán crater on the lunar farside, the Yutu‐2 rover, part of China's Chang'e‐4 mission, come across rock fragments with higher albedo than the surrounding surface. This study investigates their origin, emplacement, and composition based on in situ spectral analysis and geological considerations. The spectral signatures of two fragments show a clear dominance of low‐calcium pyroxenes against the high‐calcium phases characteristic of the basalts infilling the Von Kármán crater. Based on spectral considerations, this suggests an allochthonous origin for the ejecta fragments, with the most likely source attributable to the Imbrian 73‐km Finsen crater. We propose that these rock fragments might have had a convoluted history, born as ejected target materials from the Imbrian Finsen impact, possibly buried and resurfaced several times within Von Kármán by the churning mechanisms that continuously reshape the lunar surface, and finally exhumed by a secondary impact from the Copernican 3.8‐km Zhinyu crater.