Toward Detecting Polycyclic Aromatic Hydrocarbons on Planetary Objects with ORIGIN

Polycyclic aromatic hydrocarbons (PAHs) are found on various planetary surfaces in the solar system. They are proposed to play a role in the emergence of life, as molecules that are important for biological processes could be derived from them. In this work, four PAHs (pyrene, perylene, anthracene, and coronene) were measured using the ORganics Information Gathering INstrument system (ORIGIN), a lightweight laser desorption ionization-mass spectrometer designed for space exploration missions. In this contribution, we demonstrate the current measurement capabilities of ORIGIN in detecting PAHs at different concentrations and applied laser pulse energies. Furthermore, we show that chemical processing of the PAHs during measurement is limited and that the parent mass can be detected in the majority of cases. The instrument achieves a 3σ detection limit in the order of femtomol mm−2 for all four PAHs, with the possibility of further increasing this sensitivity. This work illustrates the potential of ORIGIN as an instrument for the detection of molecules important for the emergence or presence of life, especially when viewed in combination with previous results by the instrument, such as the identification of amino acids. ORIGIN could be used on a lander or rover platform for future in situ missions to targets in the solar system, such as the icy moons of Jupiter or Saturn

Improved limit of detection of a high-resolution fs-LIMS instrument through mass-selective beam blanking

Laser Ablation Ionisation Mass Spectrometry (LIMS) is an important quantitative method for chemical analysis of solids. Current limits of detections (LoDs) of LIMS instruments are in the ppm to sub-ppm range (atomic fractions), while other commonly used techniques for solid sample analysis reach LoDs at ppb levels or even below. This study presents the implementation of mass-selective beam blanking in the Laser Mass Spectrometer – Gran Turismo (LMS-GT) to improve the instruments’ detection limit. LMS-GT is a high-performance time-of-flight LIMS instrument coupled to a femtosecond laser ablation ion source reaching micrometre spatial resolutions and mass resolutions 12′000. A fast high voltage switch was developed in-house to induce potential changes at an Einzel lens at the intermediate time focus of the ion trajectory, leading to short deflections of the ion beam and hindering selected species from reaching the detector. The intensities of single mass lines are reduced with 100% efficiency to below the noise floor when blanked. The detector gain can safely be increased while blanking the most intense mass lines simultaneously, thus improving the detection limit. The LoD of LMS-GT prior to the installation of the mass-selective blanking device was at ppm level (at. frac.) with few sub-ppm detections, the installation pushed it to the lower ppb range, without compromising the initial performance. This emphasises that fs-LIMS can be a powerful quantitative technique for the chemical analysis of solids, with the potential to reach the levels of mass spectrometric analysis achievable with Secondary Ion Mass Spectrometry (SIMS) and Laser Ablation–Inductively Coupled Plasma–Mass Spectrometry (LA-ICP-MS)

Prototype laser desorption/ionization mass spectrometer for in situ biosignature detection on ocean worlds

Instrumentatio

Correlation Network Analysis for Amino Acid Identification in Soil Samples With the ORIGIN Space-Prototype Instrument

The detection of biomolecules on Solar System bodies can help us to understand how life emerged on Earth and how life may be distributed in our Solar System. However, the detection of chemical signatures of life on planets or their moons is challenging. A variety of parameters must be considered, such as a suited landing site location, geological and environmental processes favourable to life, life detection strategies, and the application of appropriate and sensitive instrumentation. In this contribution, recent results obtained using our novel laser desorption mass spectrometer ORganics INformation Gathering Instrument (ORIGIN), an instrument designed for in situ space exploration, are presented. We focus in this paper on the detection and identification of amino acid extracts from a natural permafrost sample, as well as in an analogue mixture of soils and amino acids. The resulting dataset was analysed using a correlation network analysis method. Based on mass spectrometric correlation, amino acid signatures were separated from soil signatures, identifying chemically different molecular components in complex samples. The presented analysis method represents an alternative to the typically applied spectra-by-spectra analysis for the evaluation of mass spectrometric data and, therefore, is of high interest for future application in space exploration missions

Towards detecting carbon chemistry on planetary objects with the ORIGIN space instrument

Instrumentatio

The luminosity-redshift relation in brane-worlds: II. Confrontation with experimental data

The luminosity distance - redshift relation for a wide class of generalized Randall-Sundrum type II brane-world models with Weyl fluid is compared to the presently available supernova data. We find that there is a class of spacially flat models with different amounts of matter $\Omega_{\rho}$ and Weyl fluid $\Omega_{d}$, which have a very similar fitting quality. The best-fit models are equally likely and can be regarded as extensions of the $\Lambda$CDM model, which is also included. We examine three models with different evolutionary history of the Weyl fluid, characterized by a parameter $\alpha =0,~2$ and$~3$. The first model describes a brane which had radiated energy into the bulk some time ago, but in recent times this energy exchange has ceased and only a dark radiation ($\alpha =0$) is left. In the other two models the Weyl-fluid describes a radiating brane throughout the cosmological evolution, up to our days. We find that the trought of the fitting surface extends over a wider $\Omega_{d}$-range with increasing $\alpha$, but the linear correlation of $\Omega_{d}$ and $\Omega_{\rho}$ holds all over the examined $\Omega_{d}$ range.Comment: Comparison with observations enhanced as compared to v1 of astro-ph/0606698. Discussion based on Gold2006 data set included, preferred values of cosmological parameters given. Argument supporting a relatively high value of the dark radiation developed. v2: Tests of radiating brane models included, published version (15 pages, 10 figures

All-sky search for gravitational-wave bursts in the second joint LIGO-Virgo run

We present results from a search for gravitational-wave bursts in the data collected by the LIGO and Virgo detectors between July 7, 2009 and October 20, 2010: data are analyzed when at least two of the three LIGO-Virgo detectors are in coincident operation, with a total observation time of 207 days. The analysis searches for transients of duration < 1 s over the frequency band 64-5000 Hz, without other assumptions on the signal waveform, polarization, direction or occurrence time. All identified events are consistent with the expected accidental background. We set frequentist upper limits on the rate of gravitational-wave bursts by combining this search with the previous LIGO-Virgo search on the data collected between November 2005 and October 2007. The upper limit on the rate of strong gravitational-wave bursts at the Earth is 1.3 events per year at 90% confidence. We also present upper limits on source rate density per year and Mpc^3 for sample populations of standard-candle sources. As in the previous joint run, typical sensitivities of the search in terms of the root-sum-squared strain amplitude for these waveforms lie in the range 5 10^-22 Hz^-1/2 to 1 10^-20 Hz^-1/2. The combination of the two joint runs entails the most sensitive all-sky search for generic gravitational-wave bursts and synthesizes the results achieved by the initial generation of interferometric detectors.Comment: 15 pages, 7 figures: data for plots and archived public version at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=70814&version=19, see also the public announcement at http://www.ligo.org/science/Publication-S6BurstAllSky

Strain-induced trace element mobility in a quartz-sulphide vein system. An example from the ONKALO™ spent nuclear fuel repository (Olkiluoto, SW Finland)

This work investigates element mobility and deformation mechanisms in sulphide-bearing quartz veins associated with a strike-slip fault exposed in the ONKALO™ Finnish deep repository for spent nuclear fuel (Olkiluoto Island, southwest Finland). It combines petrography, trace element mapping by Laser Ablation Inductively Coupled Plasma Time-of-Flight Mass Spectrometry (LA-ICP-TOFMS) and Electron Backscattered Diffraction (EBSD) analysis of representative microstructures. The fault core was reactivated by brittle deformation episodes assisted by hydrothermal fluid batches with distinct trace element signatures. LA-ICP-TOFMS element distribution maps and EBSD on sulphides reveal local, syn-deformational intragrain enrichment of primary and secondary elements (i.e., As, Co, Cu, Ag, Sn, Sb, Pb, Se, In, Te). Trace element enrichments occur by a combination of microscale plastic distortions and microfracturing at the reaction fronts. Fluid ingress along microcracks enhanced chemical replacement of pyrite that combined with element diffusion along dislocations and tilt boundaries controlled trace element mobility in sulphides at the small scale. At the scale of the vein system, the competence contrast between inclusions of soft sulphides in the harder host quartz may have favored local fracture nucleation and fluid flow