journal
MENU ▼
Read by QxMD icon Read
search

Astrobiology

journal
https://www.readbyqxmd.com/read/27893284/biomarkers-and-metabolic-patterns-in-the-sediments-of-evolving-glacial-lakes-as-a-proxy-for-planetary-lake-exploration
#1
Víctor Parro, Yolanda Blanco, Fernando Puente-Sánchez, Luis A Rivas, Mercedes Moreno-Paz, Alex Echeverría, Guillermo Chong-Díaz, Cecilia Demergasso, Nathalie A Cabrol
Oligotrophic glacial lakes in the Andes Mountains serve as models to study the effects of climate change on natural biological systems. The persistent high UV regime and evolution of the lake biota due to deglaciation make Andean lake ecosystems potential analogues in the search for life on other planetary bodies. Our objective was to identify microbial biomarkers and metabolic patterns that represent time points in the evolutionary history of Andean glacial lakes, as these may be used in long-term studies as microscale indicators of climate change processes...
November 28, 2016: Astrobiology
https://www.readbyqxmd.com/read/27870548/onboard-science-insights-and-vehicle-dynamics-from-scale-model-trials-of-the-titan-mare-explorer-time-capsule-at-laguna-negra-chile
#2
Ralph D Lorenz, Nathalie A Cabrol
A scale model of the proposed Titan Mare Explorer capsule was deployed at the Planetary Lake Lander field site at Laguna Negra, Chile. The tests served to calibrate models of wind-driven drift of the capsule and to understand its attitude motion in the wave field, as well as to identify dynamic and acoustic signatures of shoreline approach. This information enables formulation of onboard trigger criteria for near-shore science data acquisition. Key Words: Titan-Vehicle dynamics-Science autonomy-Lake. Astrobiology 17, xxx-xxx...
November 21, 2016: Astrobiology
https://www.readbyqxmd.com/read/28103108/secondary-school-students-knowledge-and-opinions-on-astrobiology-topics-and-related-social-issues
#3
Raquel Oreiro, Jordi Solbes
Astrobiology is the study of the origin of life on Earth and the distribution of life in the Universe. Its multidisciplinary approach, social and philosophical implications, and appeal within the discipline and beyond make astrobiology a uniquely qualified subject for general science education. In this study, student knowledge and opinions on astrobiology topics were investigated. Eighty-nine students in their last year of compulsory education (age 15) completed a written questionnaire that consisted of 10 open questions on the topic of astrobiology...
January 2017: Astrobiology
https://www.readbyqxmd.com/read/28103107/star-masses-and-star-planet-distances-for-earth-like-habitability
#4
David Waltham
This paper presents statistical estimates for the location and duration of habitable zones (HZs) around stars of different mass. The approach is based upon the assumption that Earth's location, and the Sun's mass, should not be highly atypical of inhabited planets. The results support climate-model-based estimates for the location of the Sun's HZ except models giving a present-day outer-edge beyond 1.64 AU. The statistical approach also demonstrates that there is a habitability issue for stars smaller than 0...
January 2017: Astrobiology
https://www.readbyqxmd.com/read/28103106/low-temperature-alkaline-ph-hydrolysis-of-oxygen-free-titan-tholins-carbonates-impact
#5
Coralie Brassé, Arnaud Buch, Patrice Coll, François Raulin
Titan, the largest moon of Saturn, is one of the key planetary objects in the field of exobiology. Its dense, nitrogen-rich atmosphere is the site of important organic chemistry. This paper focuses on the organic aerosols produced in Titan's atmosphere that play an important role in atmospheric and surface processes and in organic chemistry as it applies to exobiological interests. To produce reliable laboratory analogues of these aerosols, we developed, tested, and optimized a device for the synthesis of clean tholins...
January 2017: Astrobiology
https://www.readbyqxmd.com/read/28103105/evolution-of-earth-like-extrasolar-planetary-atmospheres-assessing-the-atmospheres-and-biospheres-of-early-earth-analog-planets-with-a-coupled-atmosphere-biogeochemical-model
#6
S Gebauer, J L Grenfell, J W Stock, R Lehmann, M Godolt, P von Paris, H Rauer
Understanding the evolution of Earth and potentially habitable Earth-like worlds is essential to fathom our origin in the Universe. The search for Earth-like planets in the habitable zone and investigation of their atmospheres with climate and photochemical models is a central focus in exoplanetary science. Taking the evolution of Earth as a reference for Earth-like planets, a central scientific goal is to understand what the interactions were between atmosphere, geology, and biology on early Earth. The Great Oxidation Event in Earth's history was certainly caused by their interplay, but the origin and controlling processes of this occurrence are not well understood, the study of which will require interdisciplinary, coupled models...
January 2017: Astrobiology
https://www.readbyqxmd.com/read/28072548/conference-report-biosignature-preservation-and-detection-in-mars-analog-environments
#7
Lindsay Hays, David Beaty
The Conference on Biosignature Preservation and Detection in Mars Analog Environments held in May 2016 brought together scientists to discuss microbial biosignatures in Mars analog habitable environments. Five analog environments were discussed: (1) hydrothermal spring systems, (2) subaqueous environments, (3) subaerial environments, (4) subsurface environments, and (5) iron-rich systems. This paper details the major messages that resulted from the discussions and will be followed by a review paper that adds significant detail from the published literature and interpretations from the writing committee of the workshop for future research and application to astrobiological exploration missions...
January 2017: Astrobiology
https://www.readbyqxmd.com/read/28068148/element-cycling-and-energy-flux-responses-in-ecosystem-simulations-conducted-at-the-chinese-lunar-palace-1
#8
Chen Dong, Yuming Fu, Beizhen Xie, Minjuan Wang, Hong Liu
Bioregenerative life-support systems (BLSS) address interactions between organisms and their environment as an integrated system through the study of factors that regulate the pools and fluxes of materials and energy through ecological systems. As a simple model, using BLSS is very important in the investigation of element cycling and energy flux for sustainable development on Earth. A 105-day experiment with a high degree of closure was carried out in this system from February to May, 2014, with three volunteers...
January 2017: Astrobiology
https://www.readbyqxmd.com/read/28051326/g-equivalent-acceleration-tolerance-in-the-eutardigrade-species-hypsibius-dujardini
#9
Tarushika Vasanthan, Lorea Alejaldre, Jessica Hider, Shreya Patel, Nabiha Husain, Bavithra Umapathisivam, Jonathon Stone
Tardigrades are microscopic organisms renowned for their ability to survive extreme environmental conditions. Tardigrade extreme-tolerance research has centered on the ability to withstand desiccation, low and high temperatures, and high hydrostatic pressure and radiation levels. Tardigrade tolerance to hypergravity, however, has yet to be described. We used the eutardigrade species Hypsibius dujardini to investigate short-term tolerance to g-equivalent accelerations (i.e., mimicking g-forces). Data obtained from specimens centrifuged between 3421g and 16,060g for 1 min inclusively reveal tolerance in an acceleration-dependent relation, with lower survivorship and egg production at higher accelerations...
January 2017: Astrobiology
https://www.readbyqxmd.com/read/28026990/a-possible-role-for-stochastic-astrophysical-ionizing-radiation-events-in-the-systematic-disparity-between-molecular-and-fossil-dates
#10
Adrian L Melott
Major discrepancies have been noted for some time between fossil ages and molecular divergence dates for a variety of taxa. Recently, systematic trends within avian clades have been uncovered. The trends show that the disparity is much larger for mitochondrial DNA than for nuclear DNA, also that it is larger for crown fossil dates than stem fossil dates. It has been argued that this pattern is largely inconsistent with incompleteness of the fossil record as the principal driver of the disparity. A case is presented that, given the expected mutations from a fluctuating background of astrophysical radiation from such sources as supernovae, the rate of molecular clocks is variable and should increase back to a few million years, before returning to the long-term average rate...
January 2017: Astrobiology
https://www.readbyqxmd.com/read/28026989/should-we-invest-in-martian-brine-research-to-reduce-mars-exploration-costs
#11
Javier Martín-Torres, María-Paz Zorzano
No abstract text is available yet for this article.
January 2017: Astrobiology
https://www.readbyqxmd.com/read/28001448/following-the-interstellar-history-of-carbon-from-the-interiors-of-stars-to-the-surfaces-of-planets
#12
L M Ziurys, D T Halfen, W Geppert, Y Aikawa
The chemical history of carbon is traced from its origin in stellar nucleosynthesis to its delivery to planet surfaces. The molecular carriers of this element are examined at each stage in the cycling of interstellar organic material and their eventual incorporation into solar system bodies. The connection between the various interstellar carbon reservoirs is also examined. Carbon has two stellar sources: supernova explosions and mass loss from evolved stars. In the latter case, the carbon is dredged up from the interior and then ejected into a circumstellar envelope, where a rich and unusual C-based chemistry occurs...
December 2016: Astrobiology
https://www.readbyqxmd.com/read/27925795/oxidants-at-the-surface-of-mars-a-review-in-light-of-recent-exploration-results
#13
J Lasne, A Noblet, C Szopa, R Navarro-González, M Cabane, O Poch, F Stalport, P François, S K Atreya, P Coll
In 1976, the Viking landers carried out the most comprehensive search for organics and microbial life in the martian regolith. Their results indicate that Mars' surface is lifeless and, surprisingly, depleted in organics at part-per-billion levels. Several biology experiments on the Viking landers gave controversial results that have since been explained by the presence of oxidizing agents on the surface of Mars. These oxidants may degrade abiotic or biological organics, resulting in their nondetection in the regolith...
December 2016: Astrobiology
https://www.readbyqxmd.com/read/27912029/how-to-establish-a-bioregenerative-life-support-system-for-long-term-crewed-missions-to-the-moon-or-mars
#14
Yuming Fu, Leyuan Li, Beizhen Xie, Chen Dong, Mingjuan Wang, Boyang Jia, Lingzhi Shao, Yingying Dong, Shengda Deng, Hui Liu, Guanghui Liu, Bojie Liu, Dawei Hu, Hong Liu
To conduct crewed simulation experiments of bioregenerative life support systems on the ground is a critical step for human life support in deep-space exploration. An artificial closed ecosystem named Lunar Palace 1 was built through integrating efficient higher plant cultivation, animal protein production, urine nitrogen recycling, and bioconversion of solid waste. Subsequently, a 105-day, multicrew, closed integrative bioregenerative life support systems experiment in Lunar Palace 1 was carried out from February through May 2014...
December 2016: Astrobiology
https://www.readbyqxmd.com/read/27912028/formation-and-persistence-of-brine-on-mars-experimental-simulations-throughout-the-diurnal-cycle-at-the-phoenix-landing-site
#15
E Fischer, G M Martínez, N O Rennó
In the last few years, water ice and salts capable of melting this ice and producing liquid saline water (brine) have been detected on Mars. Moreover, indirect evidence for brine has been found in multiple areas of the planet. Here, we simulate full diurnal cycles of temperature and atmospheric water vapor content at the Phoenix landing site for the first time and show experimentally that, in spite of the low Mars-like chamber temperature, brine forms minutes after the ground temperature exceeds the eutectic temperature of salts in contact with water ice...
December 2016: Astrobiology
https://www.readbyqxmd.com/read/27905827/modeling-pn2-through-geological-time-implications-for-planetary-climates-and-atmospheric-biosignatures
#16
E E Stüeken, M A Kipp, M C Koehler, E W Schwieterman, B Johnson, R Buick
Nitrogen is a major nutrient for all life on Earth and could plausibly play a similar role in extraterrestrial biospheres. The major reservoir of nitrogen at Earth's surface is atmospheric N2, but recent studies have proposed that the size of this reservoir may have fluctuated significantly over the course of Earth's history with particularly low levels in the Neoarchean-presumably as a result of biological activity. We used a biogeochemical box model to test which conditions are necessary to cause large swings in atmospheric N2 pressure...
December 2016: Astrobiology
https://www.readbyqxmd.com/read/27901343/colonization-of-snow-by-microorganisms-as-revealed-using-miniature-raman-spectrometers-possibilities-for-detecting-carotenoids-of-psychrophiles-on-mars
#17
Jan Jehlička, Adam Culka, Linda Nedbalová
We tested the potential of a miniaturized Raman spectrometer for use in field detection of snow algae pigments. A miniature Raman spectrometer, equipped with an excitation laser at 532 nm, allowed for the detection of carotenoids in cells of Chloromonas nivalis and Chlamydomonas nivalis at different stages of their life cycle. Astaxanthin, the major photoprotective pigment, was detected in algal blooms originating in snows at two alpine European sites that differed in altitude (Krkonoše Mts., Czech Republic, 1502 m a...
December 2016: Astrobiology
https://www.readbyqxmd.com/read/27870556/twenty-species-of-hypobarophilic-bacteria-recovered-from-diverse-soils-exhibit-growth-under-simulated-martian-conditions-at-0-7%C3%A2-kpa
#18
Andrew C Schuerger, Wayne L Nicholson
Bacterial growth at low pressure is a new research area with implications for predicting microbial activity in clouds and the bulk atmosphere on Earth and for modeling the forward contamination of planetary surfaces like Mars. Here, we describe experiments on the recovery and identification of 20 species of bacterial hypobarophiles (def., growth under hypobaric conditions of approximately 1-2 kPa) in 10 genera capable of growth at 0.7 kPa. Hypobarophilic bacteria, but not archaea or fungi, were recovered from diverse soils, and high numbers of hypobarophiles were recovered from Arctic and Siberian permafrost soils...
December 2016: Astrobiology
https://www.readbyqxmd.com/read/27870586/organic-matter-detection-on-mars-by-pyrolysis-ftir-an-analysis-of-sensitivity-and-mineral-matrix-effects
#19
Peter R Gordon, Mark A Sephton
Returning samples from Mars will require an effective method to assess and select the highest-priority geological materials. The ideal instrument for sample triage would be simple in operation, limited in its demand for resources, and rich in produced diagnostic information. Pyrolysis-Fourier infrared spectroscopy (pyrolysis-FTIR) is a potentially attractive triage instrument that considers both the past habitability of the sample depositional environment and the presence of organic matter that may reflect actual habitation...
November 2016: Astrobiology
https://www.readbyqxmd.com/read/27870585/another-earth-2-0-not-so-fast
#20
Dirk Schulze-Makuch, Edward Guinan
The number of confirmed exoplanets now exceeds 3000, with an additional nearly 5000 exoplanet candidates awaiting confirmation in the NASA Exoplanet Archive ( 2016 ). Nearly weekly we hear about the detection of a new exoplanet similar in mass to Earth and located in the so-called habitable zone around its host star. The excitement is understandable given our desire to find a second Earth. However, the excitement should not lead to an over-interpretation of the findings, because the claim can only be to have some crude similarity to Earth based on a few selected geophysical parameters...
November 2016: Astrobiology
journal
journal
39128
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"