Examinando por Autor "Molina, A."

Mostrando 1 - 6 de 6

Acceso Abierto
Dark microbiome and extremely low organics in Atacama fossil delta unveil Mars life detection limits
(Nature Publishing Group, 2023-02-21) Azua Bustos, A.; Fairén, A.; González Silva, C.; Prieto Ballesteros, O.; Carrizo, D.; Sánchez García, L.; Parro García, V.; Fernández Martínez, M. A.; Escudero, C.; Muñoz Iglesias, V.; Fernández Sampedro, M.; Molina, A.; García Villadangos, M.; Moreno Paz, M.; Wierzchos, J.; Ascaso, C.; Fornado, Teresa; Brucato, J. R.; Poggiali, G.; Manrique, J. A.; Veneranda, M.; López Reyes, G.; Sanz Arranz, A.; Rull, F.; Ollila, A. M.; Wiens, R. C.; Reyes Newell, Adriana; Clegg, S. M.; Millan, Maëva; Stewart Johnson, Sarah; McIntosh, Ophélie; Szopa, Cyril; Freissinet, Caroline; Sekine, Yasuhito; Fukushi, Keisuke; Morida, Koki; Inoue, Kosuke; Sakuma, Hiroshi; Rampe, E.; European Commission (EC); Ministerio de Economía y Competitividad (MINECO); Japan Society for the Promotion of Science (JSPS); Comunidad de Madrid; National Aeronautics and Space Administration (NASA); Agenzia Spaziale Italiana (ASI); Agencia Estatal de Investigación (AEI); Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Identifying unequivocal signs of life on Mars is one of the most important objectives for sending missions to the red planet. Here we report Red Stone, a 163-100 My alluvial fan–fan delta that formed under arid conditions in the Atacama Desert, rich in hematite and mudstones containing clays such as vermiculite and smectites, and therefore geologically analogous to Mars. We show that Red Stone samples display an important number of microorganisms with an unusual high rate of phylogenetic indeterminacy, what we refer to as “dark microbiome”, and a mix of biosignatures from extant and ancient microorganisms that can be barely detected with state-of-the-art laboratory equipment. Our analyses by testbed instruments that are on or will be sent to Mars unveil that although the mineralogy of Red Stone matches that detected by ground-based instruments on the red planet, similarly low levels of organics will be hard, if not impossible to detect in Martian rocks depending on the instrument and technique used. Our results stress the importance in returning samples to Earth for conclusively addressing whether life ever existed on Mars.
Acceso Abierto
Fingerprinting molecular and isotopic biosignatures on different hydrothermal scenarios of Iceland, an acidic and sulfur-rich Mars analog
(Springer Nature, 2020-12) Sánchez García, L.; Carrizo, D.; Molina, A.; Muñoz Iglesias, V.; Lezcano, M. A.; Fernández Sampedro, M.; Parro García, V.; Prieto Ballesteros, O.; European Research Council (ERC); Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Detecting signs of potential extant/extinct life on Mars is challenging because the presence of organics on that planet is expected to be very low and most likely linked to radiation-protected refugia and/or preservative strategies (e.g., organo-mineral complexes). With scarcity of organics, accounting for biomineralization and potential relationships between biomarkers, mineralogy, and geochemistry is key in the search for extraterrestrial life. Here we explored microbial fingerprints and their associated mineralogy in Icelandic hydrothermal systems analog to Mars (i.e., high sulfur content, or amorphous silica), to identify potentially habitable locations on that planet. The mineralogical assemblage of four hydrothermal substrates (hot springs biofilms, mud pots, and steaming and inactive fumaroles) was analyzed concerning the distribution of biomarkers. Molecular and isotopic composition of lipids revealed quantitative and compositional differences apparently impacted by surface geothermal alteration and environmental factors. pH and water showed an influence (i.e., greatest biomass in circumneutral settings with highest supply and turnover of water), whereas temperature conditioned the mineralogy that supported specific microbial metabolisms related with sulfur. Raman spectra suggested the possible coexistence of abiotic and biomediated sources of minerals (i.e., sulfur or hematite). These findings may help to interpret future Raman or GC–MS signals in forthcoming Martian missions.
Acceso Abierto
Frozen ground and snow cover monitoring in Livingston and Deception islands, Antarctica: preliminary results of the 2015-2019 PERMASNOW project
(Universidad de la Rioja, 2020-02-15) De Pablo, M. A.; Jiménez, J. J.; Ramos, M.; Prieto, M.; Molina, A.; Vieira, G.; Hidalgo, M. A.; Fernández, S.; Fernández Menéndez, Susana del Carmen; Calleja, J. F.; Peón, J. J.; Corbea Pérez, A.; Maior, C. N.; Morales, M.; Mora, C.; Ministerio de Economía y Competitividad (MINECO); Universidad de Alcalá; 0000-0002-5038-2022; 0000-0002-0843-3658; 0000-0001-7551-2236; 0000-0002-4496-2741; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Since 2006, our research team has been establishing in the islands of Livingston and Deception, (South Shetland archipelago, Antarctica) several monitoring stations of the active layer thickness within the international network Circumpolar Active Layer Monitoring (CALM), and the ground thermal regime for the Ground Terrestrial Network-Permafrost (GTN-P). Both networks were developed within the International Permafrost Association (IPA). In the GTN-P stations, in addition to the temperature of the air, soil, and terrain at different depths, the snow thickness is also monitored by snow poles. Since 2006, a delay in the disappearance of the snow layer has been observed, which could explain the variations we observed in the active layer thickness and permafrost temperatures. Therefore, in late 2015 our research group started the PERMASNOW project (2015-2019) to pay attention to the effect of snow cover on ground thermal This project had two different ways to study the snow cover. On the first hand, in early 2017 we deployed new instrumentation, including new time lapse cameras, snow poles with high number of sensors and a complete and complex set of instruments and sensors to configure a snow pack analyzer station providing 32 environmental and snow parameters. We used the data acquired along 2017 and 2018 years with the new instruments, together with the available from all our already existing sensors, to study in detail the snow cover. On the other hand, remote sensing data were used to try to map the snow cover, not only at our monitoring stations but the entire islands in order to map and study the snow cover distribution, as well as to start the way for future permafrost mapping in the entire islands. MODIS-derived surface temperatures and albedo products were used to detect the snow cover and to test the surface temperature. Since cloud presence limited the acquisition of valid observations of MODIS sensor, we also analyzed Terrasar X data to overcome this limitation. Remote sensing data validation required the acquirement of in situ ground-true data, consisting on data front our permanent instruments, as well as ad hoc measurements in the field (snow cover mapping, snow pits, albedo characterization, etc.). Although the project is finished, the data analysis is still ongoing. We present here the different research tasks we are developing as well as the most important results we already obtained about the snow cover. These results confirm how the snow cover duration has been changing in the last years, affecting the ground thermal behavior.
Acceso Abierto
Geomorphology of the southwest Sinus Sabaeus region: evidence for an ancient hydrological cycle on Mars
(Taylor and Francis Online, 2021-09-13) Robas, C.; Molina, A.; López, I.; Prieto Ballesteros, O.; Fairén, Alberto G.; European Research Council (ERC); Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We have produced a 1:650,000 scale geomorphological map of the southwest Sinus Sabaeus, a region of Mars approximately centered at 25.0°S and 6.5°E and located in the topographic transition between Arabia Terra and Noachis Terra, in the Martian highlands. This heavily cratered region, subjected to extensive surface erosion, shows a complex valley network system known as Marikh Vallis. In this work, we study the history and role of water in and around Marikh Vallis, focusing on the modification and evolution of this area during the earliest Martian times, the Noachian period. The map described in this paper was produced through the analysis of a combination of available imagery data, topography, and thermal inertia, which together allow defining different geomorphological units in this area. This new map provides a basis for identifying the ancient presence of water in the region, both in the liquid state and in the ice phase.
Restringido
Photogeologic Map of the Perseverance Rover Field Site in Jezero Crater Constructed by the Mars 2020 Science Team
(Springer Link, 2020-11-03) Stack, K. M.; Williams, N. R.; Calef, F. J.; Sun, V. Z.; Williford, K. H.; Farley, K. A.; Eide, S.; Flannery, D.; Hughes, C.; Jacob, S. R.; Kah, L. C.; Meyen, F.; Molina, A.; Quantin Nataf, C.; Rice, M.; Russel, P.; Scheller, E.; Seeger, C. H.; Abbey, W. J.; Adler, J. B.; Amudsen, H.; Anderson, R. B.; Ángel, S. M.; Arana, G.; Atkins, J.; Barrington, M.; Berger, T.; Borden, R.; Boring, B.; Brown, A.; Carrier, B. L.; Conrad, Pamela G.; Dypvik, H.; Fagents, S. A.; Gallegos, Z. E.; Garczynski, B.; Golder, K.; Gómez, F.; Goreva, Y.; Gupta, S.; Hamran, S. E.; Hicks, T.; Hinterman, E. D.; Horgan, B. N.; Hurowitz, J.; Johnson, J. R.; Lasue, J.; Kronyak, R. E.; Liu, Y.; Madariaga, J. M.; Mangold, N.; McClean, J.; Miklusicak, N.; Nunes, D.; Rojas, C.; Runyon, K.; Schmitz, N.; Scudder, N.; Shaver, E.; SooHoo, J.; Spaulding, R.; Stanish, E.; Tamppari, L. K.; Tice, M. M.; Turenne, N.; Willis, P. A.; Aileen Yingst, R.; European Research Council (ERC); National Aeronautics and Space Administration (NASA); Molina, A. [0000-0002-5038-2022]; Hughes, C. [0000-0002-7061-1443]; Jacob, S. [0000-0001-9950-1486]; Arana, Gorka [0000-0001-7854-855X]; Sun, V. Z. [0000-0003-1480-7369]; Stack, K. [0000-0003-3444-6695]; Williford, K. [0000-0003-0633-408X]; Flannery, D. [0000-0001-8982-496X]; Gupta, S. [0000-0001-6415-1332]; Williams, N. [0000-0003-0602-484X]; Unidad de Excelencia Científica Centro de Astrobiología María de Maeztu del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The Mars 2020 Perseverance rover landing site is located within Jezero crater, a similar to 50 km diameter impact crater interpreted to be a Noachian-aged lake basin inside the western edge of the Isidis impact structure. Jezero hosts remnants of a fluvial delta, inlet and outlet valleys, and infill deposits containing diverse carbonate, mafic, and hydrated minerals. Prior to the launch of the Mars 2020 mission, members of the Science Team collaborated to produce a photogeologic map of the Perseverance landing site in Jezero crater. Mapping was performed at a 1:5000 digital map scale using a 25 cm/pixel High Resolution Imaging Science Experiment (HiRISE) orthoimage mosaic base map and a 1 m/pixel HiRISE stereo digital terrain model. Mapped bedrock and surficial units were distinguished by differences in relative brightness, tone, topography, surface texture, and apparent roughness. Mapped bedrock units are generally consistent with those identified in previously published mapping efforts, but this study's map includes the distribution of surficial deposits and sub-units of the Jezero delta at a higher level of detail than previous studies. This study considers four possible unit correlations to explain the relative age relationships of major units within the map area. Unit correlations include previously published interpretations as well as those that consider more complex interfingering relationships and alternative relative age relationships. The photogeologic map presented here is the foundation for scientific hypothesis development and strategic planning for Perseverance's exploration of Jezero crater.
Acceso Abierto
Transition from a Subaerial to a Subnival Permafrost Temperature Regime Following Increased Snow Cover (Livingston Island, Maritime Antarctic)
(Multidisciplinary Digital Publishing Institute (MDPI), 2020-12-08) Ramos, M.; Vieira, G.; De Pablo, M. A.; Molina, A.; Jiménez Martín, Juan José; Ministerio de Ciencia e Innovación (MICINN); Ministerio de Economía y Competitividad (MINECO); Fundacao para a Ciencia e a Tecnologia (FCT); Ramos, M. [0000-0003-3648-6818]; Vieira, G. [0000-0001-7611-3464]; De Pablo, M. Á. [0000-0002-4496-2741]; Jiménez Cuenca, J. J. [0000-0001-7677-8140]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The Antarctic Peninsula (AP) region has been one of the regions on Earth with strongest warming since 1950. However, the northwest of the AP showed a cooling from 2000 to 2015, which had local consequences with an increase in snow accumulation and a deceleration in the loss of mass from glaciers. In this paper, we studied the effects of increased snow accumulation in the permafrost thermal regime in two boreholes (PG1 and PG2) in Livingston Island, South Shetlands Archipelago, from 2009 to 2015. The two boreholes located c. 300 m apart but at similar elevation showed different snow accumulation, with PG2 becoming completely covered with snow all year long, while the other remained mostly snow free during the summer. The analysis of the thermal regimes and of the estimated soil surface energy exchange during the study period showed the effects of snow insulation in reducing the active layer thickness. These effects were especially relevant in PG2, which transitioned from a subaerial to a subnival regime. There, permafrost aggraded from below, with the active layer completely disappearing and the efficiency of thermal insulation by the snowpack prevailing in the thermal regime. This situation may be used as an analogue for the transition from a periglacial to a subglacial environment in longer periods of cooling in the paleoenvironmental record. View Full-Text