scholarly journals Thermodynamycal evolution of the Earth and Mars with formation of ocean, free atmospheric oxygen and generation of life

2012 ◽  
Vol 8 (1) ◽  
pp. 49-54
Author(s):  
R.Ya. Belevtsev ◽  
K.I. Churyumov ◽  
S.D. Spivak ◽  
Е.K. Melnik
Keyword(s):  
Atmospheric Oxygen ◽  
The Earth

scholarly journals Oxygen and environmental stress in plants - an overview

1994 ◽  
Vol 102 ◽  
pp. 1-10 ◽  
Author(s):  
George A. F. Hendry ◽  
R. M. M. Crawford
Keyword(s):  
Solar System ◽  
Narrow Band ◽  
Atmospheric Oxygen ◽  
Recent Event ◽  
Radio Emissions ◽  
The Earth ◽  
Reducing Conditions ◽  
Galileo Satellite ◽  
Life On Earth ◽  
Intelligent Life

The Galileo satellite during its recent passes close to the Earth recorded a planet with an unusual red-absorbing pigment, a poisonous atmosphere, simultaneously rich in oxygen and in methane, with strong, modulated, narrow-band, radio emissions in the MHz frequencies (Sagan et al. 1993). To an observer visiting the solar system, these features; the photo-oxidisable pigment chlorophyll, abundant atmospheric oxygen, the existence of reducing conditions and intelligent life might well appear self-contradictory. While intelligent life is a recent event, the presence of other forms of life based on photosynthesis and survival under both oxygen-rich atmospheres and reducing conditions go back to the earliest times (Table 1). Life on Earth has evolved over nearly 4 G years under atmospheric environments ranging from anoxia, to hypoxia, to hyperoxia (relative to the present day), and not always in that sequence.

scholarly journals Energy metabolism among eukaryotic anaerobes in light of Proterozoic ocean chemistry

2008 ◽  
Vol 363 (1504) ◽  
pp. 2717-2729 ◽  
Author(s):  
Marek Mentel ◽  
William Martin
Keyword(s):  
Energy Metabolism ◽  
Alternative Hypothesis ◽  
Atmospheric Oxygen ◽  
Global Scale ◽  
Evolutionary Significance ◽  
Significant Finding ◽  
Eukaryotic Evolution ◽  
Important Advance ◽  
The Earth ◽  
Ocean Chemistry

Recent years have witnessed major upheavals in views about early eukaryotic evolution. One very significant finding was that mitochondria, including hydrogenosomes and the newly discovered mitosomes, are just as ubiquitous and defining among eukaryotes as the nucleus itself. A second important advance concerns the readjustment, still in progress, about phylogenetic relationships among eukaryotic groups and the roughly six new eukaryotic supergroups that are currently at the focus of much attention. From the standpoint of energy metabolism (the biochemical means through which eukaryotes gain their ATP, thereby enabling any and all evolution of other traits), understanding of mitochondria among eukaryotic anaerobes has improved. The mainstream formulations of endosymbiotic theory did not predict the ubiquity of mitochondria among anaerobic eukaryotes, while an alternative hypothesis that specifically addressed the evolutionary origin of energy metabolism among eukaryotic anaerobes did. Those developments in biology have been paralleled by a similar upheaval in the Earth sciences regarding views about the prevalence of oxygen in the oceans during the Proterozoic (the time from ca 2.5 to 0.6 Ga ago). The new model of Proterozoic ocean chemistry indicates that the oceans were anoxic and sulphidic during most of the Proterozoic. Its proponents suggest the underlying geochemical mechanism to entail the weathering of continental sulphides by atmospheric oxygen to sulphate, which was carried into the oceans as sulphate, fuelling marine sulphate reducers (anaerobic, hydrogen sulphide-producing prokaryotes) on a global scale. Taken together, these two mutually compatible developments in biology and geology underscore the evolutionary significance of oxygen-independent ATP-generating pathways in mitochondria, including those of various metazoan groups, as a watermark of the environments within which eukaryotes arose and diversified into their major lineages.

scholarly journals Trust based secure de-forestation and timber theft alert in wireless sensor networks

2018 ◽  
Vol 7 (3) ◽  
pp. 1700
Author(s):  
P N. Renjith
Keyword(s):  
Wireless Sensor Networks ◽  
Global Warming ◽  
Sensor Networks ◽  
Data Aggregation ◽  
Atmospheric Oxygen ◽  
Base Station ◽  
Wireless Sensor ◽  
Oxygen Level ◽  
The Earth

Deforestation is the permanent destruction of trees for timber and land. Deforestation and timber theft ends up with obliteration of entire forest in the earth. Deforestation has increased exponentially increase in this decade. It is well known that Deforestation is a prime reason for global warming, less tropical rainfalls and affects atmospheric oxygen level. In this paper, a novel query-based method has been intro-duced to alert deforestation to forest official. Trust analysis and data aggregation has been incorporated to improve security and fast trans-mission of information to the base station. Query based technique is used to evaluate the intrusion has been implemented. Simulation result proven that the ST-alert able to detect the trespasser and stop them from deforestation. 

scholarly journals Biological regulation of atmospheric chemistry en route to planetary oxygenation

2017 ◽  
Vol 114 (13) ◽  
pp. E2571-E2579 ◽  
Author(s):  
Gareth Izon ◽  
Aubrey L. Zerkle ◽  
Kenneth H. Williford ◽  
James Farquhar ◽  
Simon W. Poulton ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Atmospheric Chemistry ◽  
Atmospheric Oxygen ◽  
Earth System ◽  
Atmospheric Methane ◽  
Biological Regulation ◽  
Biological Source ◽  
The Earth ◽  
Methane Fluxes ◽  
Haze Formation

Emerging evidence suggests that atmospheric oxygen may have varied before rising irreversibly ∼2.4 billion years ago, during the Great Oxidation Event (GOE). Significantly, however, pre-GOE atmospheric aberrations toward more reducing conditions—featuring a methane-derived organic-haze—have recently been suggested, yet their occurrence, causes, and significance remain underexplored. To examine the role of haze formation in Earth’s history, we targeted an episode of inferred haze development. Our redox-controlled (Fe-speciation) carbon- and sulfur-isotope record reveals sustained systematic stratigraphic covariance, precluding nonatmospheric explanations. Photochemical models corroborate this inference, showing Δ36S/Δ33S ratios are sensitive to the presence of haze. Exploiting existing age constraints, we estimate that organic haze developed rapidly, stabilizing within ∼0.3 ± 0.1 million years (Myr), and persisted for upward of ∼1.4 ± 0.4 Myr. Given these temporal constraints, and the elevated atmospheric CO2 concentrations in the Archean, the sustained methane fluxes necessary for haze formation can only be reconciled with a biological source. Correlative δ13COrg and total organic carbon measurements support the interpretation that atmospheric haze was a transient response of the biosphere to increased nutrient availability, with methane fluxes controlled by the relative availability of organic carbon and sulfate. Elevated atmospheric methane concentrations during haze episodes would have expedited planetary hydrogen loss, with a single episode of haze development providing up to 2.6–18 × 1018 moles of O2 equivalents to the Earth system. Our findings suggest the Neoarchean likely represented a unique state of the Earth system where haze development played a pivotal role in planetary oxidation, hastening the contingent biological innovations that followed.

scholarly journals The Riddle of Atmospheric Oxygen: Photosynthesis or Photolysis?

2021 ◽  
Vol 95 (10) ◽  
pp. 1963-1970
Author(s):  
V. A. Davankov
Keyword(s):  
Large Scale ◽  
Atmospheric Oxygen ◽  
Sedimentary Rocks ◽  
Water Molecules ◽  
Sulfide Sulfur ◽  
Surface Layers ◽  
Free Oxygen ◽  
Parallel Processes ◽  
The Earth ◽  
First Time

Abstract The stoichiometry of the photosynthetic reaction requires that the quantities of the end products (organic biomaterial and free oxygen) be equal. However, the correct balance of the amounts of oxygen and organic matter that could have been produced by green plants on the land and in the ocean since the emergence of unique oxygenic photosynthetic systems (no more than 2.7 billion years ago) is virtually impossible, since the vast majority of oxygen was lost in oxidizing the initially reducing matter of the planet, and the bulk of organic carbon is scattered in sedimentary rocks. In recent decades, convincing information has been obtained in favor of the large-scale photolysis of water molecules in the upper atmosphere with the scattering of light hydrogen into space and the retention of heavier oxygen by gravity. This process has been operating continuously since the formation of the Earth. It is accompanied by huge losses of water and the oxidation of salts of ferrous iron and sulfide sulfur in the oceans and methane in the atmosphere. The main stages of the evolution of the atmosphere and surface layers of the Earth’s crust are analyzed for the first time in this work by considering the parallel processes of photosynthesis and photolysis. Large-scale photolysis of water also provides consistent explanations for the main stages in the evolution of the nearest planets of our Solar System.

3. Regulation

2016 ◽  
pp. 38-56
Author(s):  
Tim Lenton
Keyword(s):  
Carbon Dioxide ◽  
Atmospheric Carbon Dioxide ◽  
Atmospheric Oxygen ◽  
Biogeochemical Cycles ◽  
Global Temperature ◽  
Earth System ◽  
Animal Life ◽  
The Past ◽  
The Earth ◽  
Earth’S Climate

The Earth system has maintained habitable conditions for life over geological periods of time. These conditions include an equable global temperature, enough atmospheric carbon dioxide to fuel photosynthesis, and sufficient nutrients to grow. Furthermore, for at least the past 370 million years there has been enough atmospheric oxygen to support complex, mobile animal life, but not so much that wildfires decimated vegetation. ‘Regulation’ introduces the ways in which the biogeochemical cycles of the Earth system are self-regulated, how they are coupled to the Earth’s climate, and how scientists study this regulation.

Inspired oxygen: present, past, and future

2021 ◽  
Author(s):  
John B West
Keyword(s):  
Planetary System ◽  
Atmospheric Oxygen ◽  
Easy Access ◽  
The Moon ◽  
The Earth ◽  
Stable Oxygen ◽  
Human Space Exploration ◽  
Inspired Oxygen ◽  
Made In ◽  
Sufficient Oxygen

As earthlings, we take the oxygen in the air that we breathe for granted. Few people realize that this easy access to oxygen makes us unique in the whole universe. Nowhere else in our planetary system or in distant stars has stable oxygen ever been detected. However, the present plentiful supply of oxygen in our atmosphere was not always there. Long after the earth was formed some 4.5 billion years ago, the PO2 in the atmosphere was near zero, and it remained so for millions of years. But about 2 billion years ago, the PO2 dramatically increased to as high as 200 mmHg during the Great Oxygen Event, due to the activity of microorganisms, the cyanobacteria. Subsequently the oxygen level fell to the intermediate values that we have today. Here we also look to the future, for example, the next 50 years. This period will be special because it will include the beginnings of human space exploration, initially to the Moon and Mars. Neither of these has atmospheric oxygen. Nevertheless, plans to visit and live on both of these are developing rapidly. We consider the fascinating problems of how to how to ensure that sufficient oxygen will be available for groups of people . While it is interesting to discuss these issues now, we can expect that major advances will be made in the next few years.

Nanophase iron oxides as a key ultraviolet sunscreen for ancient photosynthetic microbes

2006 ◽  
Vol 5 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Janice L. Bishop ◽  
Stephanie K. Louris ◽  
Dana A. Rogoff ◽  
Lynn J. Rothschild
Keyword(s):  
Iron Oxide ◽  
Solar Radiation ◽  
Ultraviolet Radiation ◽  
Ferric Oxide ◽  
Near Infrared ◽  
Atmospheric Oxygen ◽  
Critical Role ◽  
Photosynthetic Organisms ◽  
The Earth ◽  
Nanophase Iron

We propose that nanophase iron-oxide-bearing materials provided important niches for ancient photosynthetic microbes on the Earth that ultimately led to the oxygenation of the Earth's atmosphere and the formation of iron-oxide deposits. Atmospheric oxygen and ozone attenuate ultraviolet radiation on the Earth today providing substantial protection for photosynthetic organisms. With ultraviolet radiation fluxes likely to have been even higher on the early Earth than today, accessing solar radiation was particularly risky for early organisms. Yet, we know that photosynthesis arose early and played a critical role in subsequent evolution. Of primary importance was protection below 290 nm, where peak nucleic acid (~260 nm) and protein (~280 nm) absorptions occur. Nanophase ferric oxide/oxyhydroxide minerals absorb, and thus block, the lethal ultraviolet radiation, while transmitting light through much of the visible and near-infrared regions of interest to photosynthesis (400 to 1100 nm). Furthermore, they were available in early environments, and are synthesized by many organisms. Based on experiments using nanophase ferric oxide/oxyhydroxide minerals as a sunscreen for photosynthetic microbes, we suggest that iron, an abundant element widely used in biological mechanisms, may have provided the protection that early organisms needed in order to be able to use photosynthetically active radiation while being protected from ultraviolet-induced damage. The results of this study are broadly applicable to astrobiology because of the abundance of iron in other potentially habitable bodies and the evolutionary pressure to utilize solar radiation when available as an energy source. This model could apply to a potential life form on Mars or other bodies where liquid water and ultraviolet radiation could have been present at significant levels. Based on ferric oxide/oxyhydroxide spectral properties, likely geologic processes, and the results of experiments with the photosynthetic organisms, Euglena sp. and Chlamydomonas reinhardtii, we propose a scenario where photosynthesis, and ultimately the oxygenation of the atmosphere, depended on the protection of early microbes by nanophase ferric oxides/oxyhydroxides.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

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