Astrobiology studies and extraterrestrial sample analysis at the Laboratory for Experimental Astrophysics - Catania

Energetic ions (galactic cosmic rays, solar wind, energetic solar ions) and UV photons are believed to significantly contribute to the evolution of solid matter in astrophysical environments. At the Laboratory for Experimental Astrophysics at INAF-Osservatorio Astrofisico di Catania samples are exposed to space conditions such as high vacuum, low temperature (15-300 K), UV irradiation (266 nm and Lyman-alpha at 121.6 nm) and fast ion bombardment (60-400 keV) and are analyzed in situ by Infrared and Raman spectroscopy. Ices, carbons and silicates have been processed and analyzed. In addition, extraterrestrial dust particles (e.g. IDPs, cometary dust particles, and meteorites) have been characterized by non destructive techniques such as micro-Raman and UV-Vis-IR spectroscopy. Furthermore, spectra of extraterrestrial samples have been compared to spectra of laboratory analogues. Here we present some of the most recent results relevant to Astrobiology and the ongoing upgrade of the experimental set-up

Solid deuterated water in space: detection constraints from laboratory experiments

The comparison between astronomical spectra and laboratory experiments is fundamental to spread light on the structure and composition of ices found in interstellar dense molecular clouds and in Solar system bodies. Water is among the most abundant solid-phase species observed in these environments, and several attempts have been made to investigate the presence of its solid-phase isotopologues. In particular, the detection of the O-D stretching mode band at 4.1 μm due to both D2O and HDO within icy grain mantles is still under debate, and no detection has been reported about the presence of these species within icy bodies in the Solar system yet. In the near future, an important contribution could derive from the data acquired in the O-D stretching mode spectral range by the sensitive instruments on board the James Webb Space Telescope. With this in mind, we performed several laboratory experiments to study the O-D stretching mode band in solid mixtures containing water and deuterated water deposited in the temperature range between 17 and 155 K, in order to simulate astrophysical relevant conditions. Furthermore, samples have been studied at various temperature and irradiated with energetic ions (200 keV H^+) in order to study the effects induced by both thermal and energetic processing. Our results provide some constraints on the detection of the 4.1 μm band in astronomical environments