Estimation of the abundance of organic matter on Ceres from VIR/Dawn data coupled to laboratory experiments

International audienceCeres is the largest object in the main belt and is a wet body with a complex geological and chemical history. Its surface is composed of opaque materials, phyllosilicates, ammonium-bearing minerals, carbonates, water ice and salts. Aliphatic organics, whose origin is still uncertain, have been detected on the Ceres surface by the imaging spectrometer Visible and Infrared Spectrometer (VIR) on board Dawn. Here, using VIR spectra, acquired with a high spatial resolution (< 100m), we analyzed in detail the organic-rich areas around the Ernutet crater, their spectral characteristics, and the associated mineralogy [2]. In addition, we investigated the abundance of aliphatic carbon on Ceres by mixing materials analogue to those identified at the surface of Ceres and compared it to the new high resolution VIR spectra. These new measurements and the experiments show that a large quantity of aliphatic carbon are present on Ceres surface and sub-surface, which likely indicate an internal origin