Planetary Terrestrial Analogues Library (PTAL) project: Raman data overview

Abstract

The multianalytical study of terrestrial analogues is a useful strategy to deepen the knowledge about the geological and environmental evolution of Mars and other extraterrestrial bodies. In spite of the increasing importance that laser‐induced breakdown spectroscopy (LIBS), near‐infrared spectroscopy (NIR), and Raman techniques are acquiring in the field of space exploration, there is a lack Web‐based platform providing free access to a wide multispectral database of terrestrial analogue materials. The Planetary Terrestrial Analogues Library (PTAL) project aims at responding to this critical need by developing and providing free Web accessibility to LIBS, NIR, and Raman data from more than 94 terrestrial analogues selected according to their congruence with Martian geological contexts. In this framework, the present manuscript provides the scientific community with a complete overview of the over 4,500 Raman spectra collected to feed the PTAL database. Raman data, obtained through the complementary use of laboratory and spacecraft‐simulator systems, confirmed the effectiveness of this spectroscopic technique for the detection of major and minor mineralogical phases of the samples, the latter being of critical importance for the recognition of geological processes that could have occurred on Mars and other planets. In light of the forthcoming missions to Mars, the results obtained through the Raman Laser Spectrometer (RLS) ExoMars Simulator offer a valuable insight on the scientific outcome that could derive from the RLS spectrometer that will soon land on Mars as part of the ExoMars rover payload.

ExoMars Raman Laser Spectrometer (RLS): development of chemometric tools to classify ultramafic igneous rocks on Mars

“…Pyroxenite terrestrial analogues (named PYR1, PYR2 and PYR3) are part of the sample collection from the ERICA research group and were collected in northern Norway. Although the exact sampling area is unknown, many localities from northern Norway are widely acknowledged for being optimal terrestrial analogs of Martian geological contexts 8 . The selected coarse materials are dark in color and, based on microscopic observations, are mainly composed of pyroxene crystals with minor but varied amounts of olivine grains.…”

“…The Raman analysis of these ultramafic rocks was performed by means of the RLS ExoMars Simulator 7 , which is considered the most reliable laboratory spectrometer to effectively emulate the scientific outcome of the RLS system onboard the Rosalind Franklin rover 8 , 9 , 37 . The instrument includes a continuous laser source emitting at 532 nm, a high resolution TE Cooled CCD Array spectrometer, an optical head with a long WD objective of 50 × and a reply of the ExoMars sample holder.…”

“…As demonstrated in preliminary studies based on the characterization of terrestrial analogs proceeding from the Planetary Terrestrial Analogues Library (PTAL) collection 8 , the RLS is able to effectively unveil the mineralogical complexity of heterogeneous geological samples, even achieving the detection of minor and trace phases 9 . Beyond the qualitative analysis of Raman spectra, further researches prove that the relative concentration ratio between major phases of sample mixtures could be determined through the chemometric analysis of RLS data sets 7 .…”

ExoFiT trial at the Atacama Desert (Chile): Raman detection of biomarkers by representative prototypes of the ExoMars/Raman Laser Spectrometer

“…Afterwards, more detailed spectroscopic analyses were carried out in the laboratory by means of the RLS ExoMars Simulator, which characteristics have been described elsewhere 20 . As detailed in previous works, this is the optimal instrument to predict the potential scientific outcome of the RLS flying model 21,22 . Indeed, in addition to the RLS-like optical spectral characteristics (as the RAD1), the spectrometer is coupled to a replicate of the ExoMars/ SPDS, and integrates the same algorithms developed for the RLS to perform the automatic multi-point analysis of Martian samples (e.g.…”

GeoRaman

“…Currently, there is a paucity of web-based platforms providing free access to multispectral databases of analogue materials. Veneranda et al [26] proposes the development of the Planetary Terrestrial Analogue Library (PTAL) project, in which they provide a complete overview of 4,500 Raman spectra collected on analogue materials which have been incorporated into the PTAL database. Additionally, research by Galende et al [27] acquired a large number Raman and VNIR spectra of common and rare phyllosilicates to develop a database called Inorganic and Mineralogical Planetary and Terrestrial compounds (IMPAT-Dat).…”