scholarly journals Mars: Life, Subglacial Oceans, Abiogenic Photosynthesis, Seasonal Increases and Replenishment of Atmospheric Oxygen

2020 ◽  
Vol 29 (1) ◽  
pp. 189-209
Author(s):  
Rhawn G. Joseph ◽  
Natalia S. Duxbury ◽  
Giora J. Kidron ◽  
Carl H. Gibson ◽  
Rudolph Schild
Keyword(s):  
Organic Matter ◽  
Green Algae ◽  
Atmospheric Oxygen ◽  
Water Molecules ◽  
Free Oxygen ◽  
Water Ice ◽  
Life On Mars ◽  
Past Life ◽  
Seasonal Melting

AbstractThe discovery and subsequent investigations of atmospheric oxygen on Mars are reviewed. Free oxygen is a biomarker produced by photosynthesizing organisms. Oxygen is reactive and on Mars may be destroyed in 10 years and is continually replenished. Diurnal and spring/summer increases in oxygen have been documented, and these variations parallel biologically induced fluctuations on Earth. Data from the Viking biological experiments also support active biology, though these results have been disputed. Although there is no conclusive proof of current or past life on Mars, organic matter has been detected and specimens resembling green algae / cyanobacteria, lichens, stromatolites, and open apertures and fenestrae for the venting of oxygen produced via photosynthesis have been observed. These life-like specimens include thousands of lichen-mushroom-shaped structures with thin stems, attached to rocks, topped by bulbous caps, and oriented skyward similar to photosynthesizing organisms. If these specimens are living, fossilized or abiogenic is unknown. If biological, they may be producing and replenishing atmospheric oxygen. Abiogenic processes might also contribute to oxygenation via sublimation and seasonal melting of subglacial water-ice deposits coupled with UV splitting of water molecules; a process of abiogenic photosynthesis that could have significantly depleted oceans of water and subsurface ice over the last 4.5 billion years.

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.

Earth’s Middle Ages: What Came after the GOE

2017 ◽  
Author(s):  
Donald Eugene Canfield
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Middle Ages ◽  
Atmospheric Oxygen ◽  
Iron Formation ◽  
Banded Iron Formation ◽  
Dissolved Iron ◽  
Great Oxidation Event ◽  
Low Levels ◽  
Substantial Rise

This chapter considers the aftermath of the great oxidation event (GOE). It suggests that there was a substantial rise in oxygen defining the GOE, which may, in turn have led to the Lomagundi isotope excursion, which was associated with high rates of organic matter burial and perhaps even higher concentrations of oxygen. This excursion was soon followed by a crash in oxygen to very low levels and a return to banded iron formation deposition. When the massive amounts of organic carbon buried during the excursion were brought into the weathering environment, they would have represented a huge oxygen sink, drawing down levels of atmospheric oxygen. There appeared to be a veritable seesaw in oxygen concentrations, apparently triggered initially by the GOE. The GOE did not produce enough oxygen to oxygenate the oceans. Dissolved iron was removed from the oceans not by reaction with oxygen but rather by reaction with sulfide. Thus, the deep oceans remained anoxic and became rich in sulfide, instead of becoming well oxygenated.

scholarly journals Organic matter and water from asteroid Itokawa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Q. H. S. Chan ◽  
A. Stephant ◽  
I. A. Franchi ◽  
X. Zhao ◽  
R. Brunetto ◽  
...  
Keyword(s):  
Organic Matter ◽  
Solar System ◽  
Parent Body ◽  
Asteroid Belt ◽  
True Nature ◽  
Water Ice ◽  
Nanocrystalline Graphite ◽  
Terrestrial Water ◽  
Solar System Bodies ◽  
Small Dust

AbstractUnderstanding the true nature of extra-terrestrial water and organic matter that were present at the birth of our solar system, and their subsequent evolution, necessitates the study of pristine astromaterials. In this study, we have studied both the water and organic contents from a dust particle recovered from the surface of near-Earth asteroid 25143 Itokawa by the Hayabusa mission, which was the first mission that brought pristine asteroidal materials to Earth’s astromaterial collection. The organic matter is presented as both nanocrystalline graphite and disordered polyaromatic carbon with high D/H and 15N/14N ratios (δD =  + 4868 ± 2288‰; δ15N =  + 344 ± 20‰) signifying an explicit extra-terrestrial origin. The contrasting organic feature (graphitic and disordered) substantiates the rubble-pile asteroid model of Itokawa, and offers support for material mixing in the asteroid belt that occurred in scales from small dust infall to catastrophic impacts of large asteroidal parent bodies. Our analysis of Itokawa water indicates that the asteroid has incorporated D-poor water ice at the abundance on par with inner solar system bodies. The asteroid was metamorphosed and dehydrated on the formerly large asteroid, and was subsequently evolved via late-stage hydration, modified by D-enriched exogenous organics and water derived from a carbonaceous parent body.

Response : Evaluating the Evidence for Past Life on Mars

Science ◽  
1996 ◽  
Vol 274 (5295) ◽  
pp. 2122-2123
Author(s):  
Simon J. Clemett ◽  
Richard N. Zare
Keyword(s):  
Life On Mars ◽  
Past Life

scholarly journals Tracing nitrate sources using the isotopic composition of skeletal-bound organic matter from the calcareous green algae Halimeda

Coral Reefs ◽  
2018 ◽  
Vol 37 (4) ◽  
pp. 1003-1011
Author(s):  
Dirk V. Erler ◽  
Luke Nothdurft ◽  
Mardi McNeil ◽  
Charly A. Moras
Keyword(s):  
Organic Matter ◽  
Isotopic Composition ◽  
Green Algae ◽  
Nitrate Sources

scholarly journals ЗАКОНОМІРНОСТІ ФОРМУВАННЯ ФІТОПЛАНКТОНУ ЗА РІЗНИХ КОНЦЕНТРАЦІЙ БІОГЕННИХ ЕЛЕМЕНТІВ ТА ОРГАНІЧНОЇ РЕЧОВИНИ

2019 ◽  
Vol 75 (1) ◽  
pp. 43-51
Author(s):  
O. V. Kravtsova ◽  
V. I. Scherbak ◽  
M. I. Linchuk
Keyword(s):  
Organic Matter ◽  
Green Algae ◽  
Seasonal Dynamics ◽  
Inorganic Nitrogen ◽  
Biogenic Elements ◽  
Hydrochemical Regime ◽  
Dissolved Phosphorus ◽  
Growing Seasons ◽  
Total Inorganic Nitrogen ◽  
Plankton Communities

The seasonal dynamics of the concentration of nutrients in the form of inorganic nitrogen (NH4+, NO2, NO3-, ΣN), dissolved phosphorus, organic matter and the connection with the development of phytoplankton in waters with high content of total inorganic nitrogen (from 23.31 to 102.65 mg N/dm3) and its compounds (ammonia - from 8.42 to 76.60, nitrate - from 4.94 to 15.93, nitrite - from 0.077 to 4.35 mg N/dm3) and organic matter (from 8.00 to 21.92 mg O/dm3 by permanganate oxidation values and from 58.46 to 265.2 mg O/dm3 by dichromate oxidation values) were analyzed in paper. The peculiarity of the hydrochemical regime of the reservoirs was phenomenally high relations ΣN:P (133,54-12152,86) during the growing seasons. Found that response algal plankton communities such features hydrochemical regime is a simplification of the structure due to the predominance of representatives of departments Euglenophyta, Chlorophyta and Bacillariophyta, while Chrysophyta, Dinophyta, Charophyta and presented Cryptophyta 1-3 species. The response of phytoplankton to the high content of compounds of inorganic nitrogen is the increase in the number and biomass of green algae, and organic matter - eugenic algae.THE REGULARITIES OF PHYTOPLANKTON FORMATION AT VARIOS BIOGENIC ELEMENTS AND ORGANIC MATTER CONCENTRATIONS 

scholarly journals Evaluating the Evidence for Past Life on Mars

Science ◽  
1996 ◽  
Vol 274 (5295) ◽  
pp. 2119-2125 ◽  
Author(s):  
E. Anders ◽  
C. K. Shearer ◽  
J. J. Papike ◽  
J. F. Bell ◽  
S. J. Clemett ◽  
...  
Keyword(s):  
Life On Mars ◽  
Past Life

Seasonal melting of surface water ice condensing in martian gullies

Icarus ◽  
2004 ◽  
Vol 171 (2) ◽  
pp. 272-283 ◽  
Author(s):  
Konrad J. Kossacki ◽  
Wojciech J. Markiewicz
Keyword(s):  
Surface Water ◽  
Water Ice ◽  
Seasonal Melting
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