Quantitative study of methane-nitrogen mixed clathrates using gas chromatography and Raman spectroscopy for their detection in icy surfaces of the outer solar system

Research areas:
Year:
2020
Keywords:
Ices, Raman spectroscopy, Satellites, Surface, Titan, Pluto, Triton
Authors:
Journal:
Icarus
Pages:
114182
ISSN:
0019-1035
Abstract:
Multicomponent clathrates may be present at the surface of icy bodies. However, their potential identification remains difficult in the absence of reliable spectral data. In this work, we focus on clathrates synthesized in laboratory from a gas mixture of N2 and CH4, which are particularly relevant for Titan, Triton or Pluto, and investigate their spectral signatures at low temperature (~94 K) and low pressure (down to 2 × 10−6 MPa). The molar composition of the synthesized clathrates for various gas composition were monitored using gas chromatography. Raman scattering from 50 to 4000 cm−1 was carried out, in order to identify discriminating criteria for possible detection by remote and in-situ observations of icy bodies of the outer Solar System. Our experimental results indicate that the identification of CH4-N2 binary clathrate from in-situ Raman spectroscopy may provide a clear determination of clathrate composition.