Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Astrobiology ; 22(4): 416-438, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35041521

RESUMO

The Mars 2020 Perseverance rover landed on February 18, 2021, and has started ground operations. The ExoMars Rosalind Franklin rover will touch down on June 10, 2023. Perseverance will be the first-ever Mars sample caching mission-a first step in sample return to Earth. SuperCam and Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) on Perseverance, and Raman Laser Spectrometer (RLS) on Rosalind Franklin, will comprise the first ever in situ planetary mission Raman spectroscopy instruments to identify rocks, minerals, and potential organic biosignatures on Mars' surface. There are many challenges associated when using Raman instruments and the optimization and quantitative analysis of resulting data. To understand how best to overcome them, we performed a comprehensive Raman analysis campaign on CanMars, a Mars sample caching rover analog mission undertaken in Hanksville, Utah, USA, in 2016. The Hanksville region presents many similarities to Oxia Planum's past habitable conditions, including liquid water, flocculent, and elemental compounds (such as clays), catalysts, substrates, and energy/food sources for life. We sampled and conducted a complete band analysis of Raman spectra as mission validation analysis with the RLS ExoMars Simulator or RLS Sim, a breadboard setup representative of the ExoMars RLS instrument. RLS Sim emulates the operational behavior of RLS on the Rosalind Franklin rover. Given the high fidelity of the Mars analog site and the RLS Sim, the results presented here may provide important information useful for guiding in situ analysis and sample triage for caching relevant for the Perseverance and Rosalind Franklin missions. By using the RLS Sim on CanMars samples, our measurements detected oxides, sulfates, nitrates, carbonates, feldspars, and carotenoids, many with a higher degree of sensitivity than past results. Future work with the RLS Sim will aim to continue developing and improving the capability of the RLS system in the future ExoMars mission.


Assuntos
Exobiologia , Marte , Planeta Terra , Exobiologia/métodos , Lasers , Minerais/análise
2.
Astrobiology ; 21(11): 1350-1362, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34314603

RESUMO

Laser-induced fluorescence spectroscopy is a useful laboratory and in situ technique for planetary exploration, with applications in biosignature detection and the search for life on Mars. However, little work has been completed on the utility of fluorescence spectroscopy techniques on asteroid relevant material. In preparation for asteroid sample return missions such as NASA's OSIRIS-REx and JAXA's Hayabusa2, we conducted UV time resolved laser-induced fluorescence spectroscopy (TR-LIF) analysis of 10 amino acids, all of which have been found in the carbonaceous meteorites Murchison and Allende. We present the calculation of decay rates of each amino acid (1.55-3.56 ns) and compare with those of relevant homogeneous minerals (15-70 ns). Moreover, we demonstrate a linear relationship between calculated lifetimes and elemental abundance of nitrogen and carbon (p < 0.025). The quantitative and qualitative fluorescence analyses presented in this work will lead to more reliable identification of organic material within meteorites and asteroids in a time-efficient, minimally destructive way.


Assuntos
Meteoroides , Aminoácidos , Exobiologia , Lasers , Espectrometria de Fluorescência
3.
Appl Spectrosc ; 75(9): 1093-1113, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33988039

RESUMO

One of the primary objectives of planetary exploration is the search for signs of life (past, present, or future). Formulating an understanding of the geochemical processes on planetary bodies may allow us to define the precursors for biological processes, thus providing insight into the evolution of past life on Earth and other planets, and perhaps a projection into future biological processes. Several techniques have emerged for detecting biomarker signals on an atomic or molecular level, including laser-induced breakdown spectroscopy (LIBS), Raman spectroscopy, laser-induced fluorescence (LIF) spectroscopy, and attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy, each of which addresses complementary aspects of the elemental composition, mineralogy, and organic characterization of a sample. However, given the technical challenges inherent to planetary exploration, having a sound understanding of the data provided from these technologies, and how the inferred insights may be used synergistically is critical for mission success. In this work, we present an in-depth characterization of a set of samples collected during a 28-day Mars analog mission conducted by the Austrian Space Forum in the Dhofar region of Oman. The samples were obtained under high-fidelity spaceflight conditions and by considering the geological context of the test site. The specimens were analyzed using the LIBS-Raman sensor, a prototype instrument for future exploration of Mars. We present the elemental quantification of the samples obtained from LIBS using a previously developed linear mixture model and validated using scanning electron microscopy energy dispersive spectroscopy. Moreover, we provide a full mineral characterization obtained using ultraviolet Raman spectroscopy and LIF, which was verified through ATR FT-IR. Lastly, we present possible discrimination of organics in the samples using LIF and time-resolved LIF. Each of these methods yields accurate results, with low errors in their predictive capabilities of LIBS (median relative error ranging from 4.5% to 16.2%), and degree of richness in subsequent inferences to geochemical and potential biochemical processes of the samples. The existence of such methods of inference and our ability to understand the limitations thereof is crucial for future planetary missions, not only to Mars and Moon but also for future exoplanetary exploration.

4.
J Eval Clin Pract ; 26(2): 604-609, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31822037

RESUMO

Today, in the age of big data, we are more capable than ever before. But even having the world at our disposal with naught but the touch of a button, we find ourselves exceedingly vulnerable in the patient chair. With insurmountable amounts of knowledge being published and disseminated around the world, how can clinicians keep up and what can be done about it? And sitting in the patient chair, bewildered by the ever-changing landscape of medicine at the blink of an eye, how can we, as patients, ever hope to be part of the conversations revolving around our own health? In this work, we explore the present-day problems of big data in the clinical context, how failing to integrate patients can result in detrimental outcomes, and what shared decision making can do about it.


Assuntos
Tomada de Decisão Compartilhada , Tomada de Decisões , Anisotropia , Comunicação , Humanos , Conhecimento
5.
Astrobiology ; 20(11): 1276-1286, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33179971

RESUMO

From February 1 to 28, 2018, the Austrian Space Forum, in cooperation with the Oman Astronomical Society and research teams from 25 nations, conducted the AMADEE-18 mission, a human-robotic Mars expedition simulation in the Dhofar region in the Sultanate of Oman. A carefully selected field crew, supported by a Mission Support Center in Innsbruck, Austria, conducted 19 experiments relevant to astrobiology, engineering disciplines, geoscience, operations research, and human factors. This expedition was the 12th in a series of analog missions that emulate selected aspects of the science expected for a human Mars mission, including the characterization of the (paleo)geological environment, human factors studies, and the search for biomarkers. In particular, an Exploration Cascade was deployed as a suggested workflow for coordinating the timing and location of the respective instruments and experiments. In validation of this workflow, the decision-making interaction between the field and the Mission Support Center was studied. This article introduces the AMADEE-18 mission and provides the mission-specific context for the other contributions of this special issue.


Assuntos
Expedições , Marte , Voo Espacial , Simulação de Ambiente Espacial , Exobiologia , Humanos , Omã
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA