Spectrophotometric analysis of the Ryugu rock seen by MASCOT: Searching for a carbonaceous chondrite analogOPEN ACCESS 

Stefan Schröder, Katharina Otto, Hannah Scharf, Klaus-Dieter Matz, Nicole Schmitz, Frank Scholten, Stefano Mottola, Frank Trauthan, Alexander Koncz, Harald Michaelis, Ralf Jaumann, Tra-Mi Ho, Hikaru Yabuta, Seiji Sugita

Submitted to Planetary Science Journal


“We analyze images of a rock on Ryugu acquired in situ by MASCam, camera of the MASCOT lander, with the aim of identifying possible carbonaceous chondrite (CC) analogs. The rock’s reflectance (rF=0.034±0.003 at phase angle 4.5∘±0.1∘) is consistent with Ryugu’s average reflectance, suggesting that the rock is typical for this asteroid. A spectrophotometric analysis of the rock’s inclusions provides clues to CC group membership. Inclusions are generally brighter than the matrix. The dominant variation in their color is a change of the visible spectral slope, with many inclusions being either red or blue. Spectral variation in the red channel hints at the presence of the 0.7~μm absorption band linked to hydrated phyllosilicates. The inclusions are unusually large for a CC; we find that their size distribution may best match that of the Renazzo (CR2) and Leoville (CV3) meteorites. The Ryugu rock does not easily fit into any of the CC groups, consistent with the idea that typical Ryugu-type meteorites are too fragile to survive atmospheric entry.”