Simulated effect of the Galactic Cosmic Rays on the surface of Pluto's dark-red region

César Feniou (1, 2) , Lora Jovanovic (1) , Thomas Gautier (1) , Nathalie Carrasco (3, 1) , Jérémy Bourgalais (1) , Philippe Boduch (4) , Hermann Rothard (4) , Basile Augé (5) , Bernard Schmitt (5) , Marie Fayolle (5) , Veronique Vuitton (5) , Olivier Poch (5) , Eric Quirico (5)

1 PLANETO - LATMOS
2 UVSQ - Université de Versailles Saint-Quentin-en-Yvelines
3 IUF - Institut universitaire de France
4 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique
5 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble

On Pluto, the largest object in the Kuiper Belt, the dark surface of Cthulhu seems to indicate the presence of photochemical aerosols, stemming from the interaction between solar ultraviolet radiation and atmospheric methane, nitrogen, carbon monoxide, and further sedimentation [1-4]. Tholins have been tested and identified as analogues of the said surface. The flyby of the New Horizons Pluto probe enabled reflectance spectra acquisitions of the Cthulhu region. Dissimilarities were found with the reflectance of Pluto tholins, which might be due to Galactic Cosmic Rays (GCR) irradiation of Pluto’s surface [5]. To test this hypothesis, Pluto tholins were synthesized and swift heavy ion irradiation was performed on the analogues to simulate the impact of cosmic rays on the surface of Cthulhu region. Moreover, GCR-analogues irradiation of the said tholins triggers a desorption of organic volatile compounds whose study could provide crucial information on both the structure of tholins and the chemical mechanisms involved. The volatile desorption was followed by mass spectrometry.

Domaines: Planète et Univers [physics]

César Feniou, Lora Jovanovic, Thomas Gautier, Nathalie Carrasco, Jérémy Bourgalais, et al.. Simulated effect of the Galactic Cosmic Rays on the surface of Pluto's dark-red region. EPSC 2020 - 14th Europlanet Science Congress 2020, Sep 2020, Virtual Meeting, Germany. pp.EPSC2020-828, ⟨10.5194/epsc2020-828⟩. ⟨insu-02919181⟩