Studying the Photo-Stability of Amino Acids in Water Ice upon Vacuum UV Irradiation

Mar 21, 2018, 5:00 PM
1h
Physikzentrum Bad Honnef

Physikzentrum Bad Honnef

Physikzentrum Bad Honnef Hauptstr. 5 53604 Bad Honnef Tel.: (0 22 24) 90 10 114 Fax: (0 22 24) 90 10 130

Speaker

Mr Vincent Kofman (Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University)

Description

The simplest amino acid, glycine, has recently been identified on the comet Churyumov–Gerasimenko (67P) [Altwegg et al., 2016]. Independent on how this and likely other amino acids have been formed - in-situ or inherited along the different chemical stages during comet formation in the Solar Nebula - the ice embedded amino acids have been exposed to radiation, including vacuum ultraviolet (VUV) radiation. We have systematically investigated in the laboratory the effect of VUV radiation (120-200 nm) [Ligterink et al. 2015] on glycine and phenylalanine at two low temperatures (10 & 100K) intimately mixed in water ice, as water is the most abundant ice in comets, on icy moons and interstellar dust grains. We present a new method to study the VUV photo-stability of amino acids in water ice and demonstrate the protective properties of water ice, as well as its effect on the photo-chemistry of amino acids [Bouwman 2009, et al. Kofman et al. in prep.]. The preliminary results indicate that water layers thicker than a few hundred nm are well capable of providing sufficient protection from VUV radiation to preserve amino acids, fully in line with the observations from the ROSETTA mission.

Primary author

Mr Vincent Kofman (Sackler Laboratory for Astrophysics, Leiden Observatory, Leiden University)

Presentation materials