Europlanet Science Congress 2021
Virtual meeting
13 – 24 September 2021
Europlanet Science Congress 2021
Virtual meeting
13 September – 24 September 2021
EPSC Abstracts
Vol. 15, EPSC2021-412, 2021, updated on 21 Jul 2021
https://doi.org/10.5194/epsc2021-412
European Planetary Science Congress 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

The Degas crater on Mercury: an interesting target for the BepiColombo mission?

Nicolas Bott1, Océane Barraud2, and Laura Guzzetta3
Nicolas Bott et al.
  • 1INAF – Osservatorio Astronomico di Roma, Monte Porzio Catone, Italy (nicolas.bott@inaf.it)
  • 2LESIA, Observatoire de Paris, Université PSL, CNRS, Université de Paris, Sorbonne Université, Meudon, France
  • 3INAF – Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy

1. Introduction

Launched on October 19th, 2018 (local time) towards Mercury, the BepiColombo spacecraft carries 16 instruments onboard the MPO and MMO orbiters. The SIMBIO-SYS (Spectrometer and Imagers for MPO BepiColombo Integrated Observatory SYStem) instrument [1] will image the surface of the innermost planet of the Solar system at unprecedented high spatial and spectral resolutions. SIMBIO-SYS is composed of 3 channels: STC (STereo Channel), a stereo camera; HRIC (High spatial Resolution Imaging Channel), a multispectral camera with a very high spatial resolution; and VIHI (Visible Infrared Hyperspectral Imager channel), a hyperspectral imager characterized by high spectral resolution and signal-to-noise ratio. The establishment of the target list for SIMBIO-SYS is underway. Therefore, studying potential targets of interest can be very useful to support their selection.

2. Data and methods

Here, we analyse the Degas crater, localized in the Shakespeare quadrangle (H-03) [2,3], hence at mid-latitudes of the northern hemisphere of Mercury (37.08°N, 232.66°E). Degas has been classified as a Kuiperian (-1 Gyr – today) crater [4] notably because of its well-preserved ray system of ejecta. We used MESSENGER data to investigate this crater with a three-fold approch: a multispectral analysis based on MDIS-WAC (Mercury Dual Imaging System-Wide Angle Camera) images have been combined with a spectroscopic analysis of MASCS (Mercury Atmospheric and Surface Composition Spectrometer) spectra and a geological analysis based on MDIS-NAC (Mercury Dual Imaging System-Narrow Angle Camera) images.

3. Preliminary results
3.1. Multispectral analysis

Using the MDIS-WAC images at the best spatial resolution available (95-250 m/pixel) and the Integrated Software for Imagers and Spectrometers (ISIS), we produced three color mosaics: an 11-bands mosaic to use all the multispectral information available with MDIS, an 8-bands mosaic to cover a wider area around the crater and study its surroundings (Figure 1), and a 3-bands mosaic with the best spatial resolution achievable (95 m/pixel).

We also produced two high-resolution monochrome mosaics using MDIS-NAC images on which geological analysis was performed (see Section 3.3).

A Principal Component Analysis (PCA) was applied to the 11-bands mosaic. The enhanced color image obtained using PC1 and PC2 reveals an asymmetric distribution of LRM (Low Reflectance Material) [5] around the crater, which suggests an oblique impact. Finally, a K-mean clustering highlights 4 spectral units: the blue deposit on the crater floor, the floor not covered by this deposit, the LRM surrounding Degas and the ejecta blankets. Close spectral properties between hollows and the blue deposit on the floor of Degas are also evidenced.

3.2. Spectroscopic analysis

MASCS spectra have been extracted from the four multispectral units (Figure 2).