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Träfflista för sökning "WFRF:(Martínez Frías Jesús) "

Sökning: WFRF:(Martínez Frías Jesús)

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  • de Vera, Jean-Pierre, et al. (författare)
  • Limits of Life and the Habitability of Mars : The ESA Space Experiment BIOMEX on the ISS
  • 2019
  • Ingår i: Astrobiology. - : Mary Ann Liebert. - 1531-1074 .- 1557-8070. ; 19:2, s. 145-157
  • Tidskriftsartikel (övrigt vetenskapligt)abstract
    • BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports-among others-the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit.
  • Gõmez-Elvira, Javier, et al. (författare)
  • Curiosity's rover environmental monitoring station : Overview of the first 100 sols
  • 2014
  • Ingår i: Journal of Geophysical Research - Planets. - 2169-9097 .- 2169-9100. ; 119:7, s. 1680-1688
  • Tidskriftsartikel (refereegranskat)abstract
    • In the first 100 Martian solar days (sols) of the Mars Science Laboratory mission, the Rover Environmental Monitoring Station (REMS) measured the seasonally evolving diurnal cycles of ultraviolet radiation, atmospheric pressure, air temperature, ground temperature, relative humidity, and wind within Gale Crater on Mars. As an introduction to several REMS-based articles in this issue, we provide an overview of the design and performance of the REMS sensors and discuss our approach to mitigating some of the difficulties we encountered following landing, including the loss of one of the two wind sensors. We discuss the REMS data set in the context of other Mars Science Laboratory instruments and observations and describe how an enhanced observing strategy greatly increased the amount of REMS data returned in the first 100 sols, providing complete coverage of the diurnal cycle every 4 to 6 sols. Finally, we provide a brief overview of key science results from the first 100 sols. We found Gale to be very dry, never reaching saturation relative humidities, subject to larger diurnal surface pressure variations than seen by any previous lander on Mars, air temperatures consistent with model predictions and abundant short timescale variability, and surface temperatures responsive to changes in surface properties and suggestive of subsurface layering. Key Points Introduction to the REMS results on MSL mission Overiview of the sensor information Overview of operational constraints
  • Hamilton, Victoria E., et al. (författare)
  • Observations and preliminary science results from the first 100 sols of MSL Rover Environmental Monitoring Station ground temperature sensor measurements at Gale Crater
  • 2014
  • Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 119:4, s. 745-770
  • Tidskriftsartikel (refereegranskat)abstract
    • We describe preliminary results from the first 100 sols of ground temperature measurements along the Mars Science Laboratory's traverse from Bradbury Landing to Rocknest in Gale. The ground temperature data show long-term increases in mean temperature that are consistent with seasonal evolution. Deviations from expected temperature trends within the diurnal cycle are observed and may be attributed to rover and environmental effects. Fits to measured diurnal temperature amplitudes using a thermal model suggest that the observed surfaces have thermal inertias in the range of 265-375?J m-2 K-1 s-1/2, which are within the range of values determined from orbital measurements and are consistent with the inertias predicted from the observed particle sizes on the uppermost surface near the rover. Ground temperatures at Gale Crater appear to warm earlier and cool later than predicted by the model, suggesting that there are multiple unaccounted for physical conditions or processes in our models. Where the Mars Science Laboratory (MSL) descent engines removed a mobile layer of dust and fine sediments from over rockier material, the diurnal temperature profile is closer to that expected for a homogeneous surface, suggesting that the mobile materials on the uppermost surface may be partially responsible for the mismatch between observed temperatures and those predicted for materials having a single thermal inertia. Models of local stratigraphy also implicate thermophysical heterogeneity at the uppermost surface as a potential contributor to the observed diurnal temperature cycle. Key Points Diurnal ground temperatures vary with location Diurnal temperature curves are not well matched by a homogeneous thermal model GTS data are consistent with a varied stratigraphy and thermophysical properties.
  • Martin-Torres, Javier, et al. (författare)
  • Transient liquid water and water activity at Gale crater on Mars
  • 2015
  • Ingår i: Nature Geoscience. - 1752-0894 .- 1752-0908. ; 8:5, s. 357-361
  • Tidskriftsartikel (refereegranskat)abstract
    • Water is a requirement for life as we know it1. Indirect evidence of transient liquid water has been observed from orbiter on equatorial Mars2, in contrast with expectations from large-scale climate models. The presence of perchlorate salts, which have been detected at Gale crater on equatorial Mars by the Curiosity rover3, 4, lowers the freezing temperature of water5. Moreover, perchlorates can form stable hydrated compounds and liquid solutions by absorbing atmospheric water vapour through deliquescence6, 7. Here we analyse relative humidity, air temperature and ground temperature data from the Curiosity rover at Gale crater and find that the observations support the formation of night-time transient liquid brines in the uppermost 5 cm of the subsurface that then evaporate after sunrise. We also find that changes in the hydration state of salts within the uppermost 15 cm of the subsurface, as measured by Curiosity, are consistent with an active exchange of water at the atmosphere–soil interface. However, the water activity and temperature are probably too low to support terrestrial organisms8. Perchlorates are widespread on the surface of Mars9 and we expect that liquid brines are abundant beyond equatorial regions where atmospheric humidity is higher and temperatures are lower.
  • Persson, Erik, et al. (författare)
  • Environment and Sustainability
  • 2018
  • Ingår i: Astrobiology and Society in Europe Today. - : Springer. - 2191-9100 .- 2191-9119. - 9783319962641 - 9783319962658 ; , s. 25-30
  • Bokkapitel (refereegranskat)abstract
    • There are strong links between astrobiology and environmental concern. Astrobiology is the study of the origin, evolution and distribution of life in the universe—including Earth. Understanding life, and in particular the basic conditions for life, is important for our ability to create a sustainable future on Earth. The connection goes both ways, however. The preservation of biodiversity and of pristine environments on Earth is of the greatest importance for our ability to study life, its origin, distribution and future. Of special interest from an astrobiology perspective is the preservation of areas with conditions that can serve as analogues to extraterrestrial environments, areas with conditions similar to those under which life originated on Earth, and in general environments where extreme adaptations can be studied. Astrobiology also presents some direct environmental challenges that need to be considered, namely in the form of forward and back contamination (discussed above in 2.3). Both issues need to be approached from a technical perspective, but also from a societal perspective. And both must be understood within a broader context of ensuring the sustainability of practices, both scientific and commercial.
  • Sebastián, Eduardo M., et al. (författare)
  • The rover environmental monitoring station ground temperature sensor : A pyrometer for measuring ground temperature on mars
  • 2010
  • Ingår i: Sensors. - 1424-8220 .- 1424-8220. ; 10:10, s. 9211-9231
  • Tidskriftsartikel (refereegranskat)abstract
    • We describe the parameters that drive the design and modeling of the Rover Environmental Monitoring Station (REMS) Ground Temperature Sensor (GTS), an instrument aboard NASA's Mars Science Laboratory, and report preliminary test results. REMS GTS is a lightweight, low-power, and low cost pyrometer for measuring the Martian surface kinematic temperature. The sensor's main feature is its innovative design, based on a simple mechanical structure with no moving parts. It includes an in-flight calibration system that permits sensor recalibration when sensor sensitivity has been degraded by deposition of dust over the optics. This paper provides the first results of a GTS engineering model working in a Martian-like, extreme environment
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