Close-up Imaging of the Ryugu Surface from the MASCOT Lander: A Spectrophotometric Analysis

The JAXA Hayabusa2 orbiter has arrived at its target, the near-Earth C-type asteroid Ryugu. On-board is the Mobile Asteroid Surface Scout (MASCOT), developed by the German Aerospace Center (DLR) with major contributions by the French space agency (CNES) [1]. MASCOT will be ejected towards the surface of Ryugu in the first half of October 2018 to land around noon local time. Its mission is expected to last about two asteroid days and nights, depending on the on-board battery performance. MASCOT will provide the first close-up view of the regolith of a C-type asteroid. For this purpose it carries a variety of instruments, one of which is a wide-field camera with a 1k × 1k CMOS detector and a multicolor LED array to illuminate the surface [2]. The camera supports both the missions of Hayabusa2 and MASCOT by characterizing the physical and scattering properties of the regolith at high spatial resolution, providing the ground truth for the remote observations by the Hayabusa2 instruments, and providing context and guidance for the Hayabusa2 sampling effort. During the asteroid day, the camera will acquire images at regular intervals, to study the reflective properties of the surface at different solar illumination angles. At night, the LEDs will be employed to illuminate the surface at 4 different wavelengths. Thus, acquisition of both day and night images will allow for a full spectrophotometric analysis of the landing site. By the time of the AGU conference, MASCOT should have successfully carried out its mission. We present the first results of our analysis and regard them in the context of observations by the orbiter instruments.

[1] Ho, T.-M. et al. (2016), SSR, DOI: 10.1007/s11214-016-0251-6, [2] Jaumann, R., et al. (2016), SSR, DOI:10.1007/s11214-016-0263-2.