Wheels within Wheels

2016 ◽  
Author(s):  
Ben McFarland
Keyword(s):  
Iron Oxide ◽  
Liquid Water ◽  
Extreme Environment ◽  
Early Earth ◽  
The Sun ◽  
Subglacial Lake ◽  
John The Baptist ◽  
Mount Rainier ◽  
Liquid Source ◽  
Red Flag

Something strange and old lurks under the ice in Antarctica, at a place called Blood Falls. It is an echo of the early Earth. Blood Falls is hard to reach and easy to find. Look through the seas of blue ice, white snow, and gray rocks for the bright-red frozen waterfall, spilling out of the ice around it in a gory cascade five stories tall. This is a red flag made from chemistry, telling that even the coldest environment on Earth is not completely dead. Liquid water can be found there, and in the water is life eking out an existence from the water around it and the dirt under it, just like it did a few billion years ago. The “blood” at Blood Falls spills out of life, but it’s not blood. Like blood, this substance is a form of iron bound to oxygen. In your blood, the protein hemoglobin hosts the iron, but Blood Falls is straight-up iron oxide, similar to rust. I saw some of this chemical last August near Mount Rainier. As we hiked up to Goat Lake, the frozen water looked dirty. The pure white ice was dusted with bright-red powder blown around from the iron-rich rocks surrounding it. The land was red as blood. That was geological, but Blood Falls is biological. It shows that life in an extreme environment eats some pretty strange food—like John the Baptist eating locusts and honey in the wilderness—and outputs blood- red iron as waste. A pocket of liquid water hides behind Blood Falls, sealed under the ice so tightly that air cannot penetrate. Even in solitude, away from the sun and oxygen, liquid water supports life. The microbes under the glacier get energy from adding oxygen to carbon to make stable CO2, just like us. The subglacial lake is sealed off from the air, so the oxygen must come from a solid or liquid source. These bacteria eat sulfate, pulling one of the four oxygens off it and producing the three-oxygen chemical sulfite.

scholarly journals The Faint Young Sun Paradox: A Simplified Thermodynamic Approach

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
F. Angulo-Brown ◽  
Marco A. Rosales ◽  
M. A. Barranco-Jiménez
Keyword(s):  
Liquid Water ◽  
Power Output ◽  
Early Stage ◽  
Energy Output ◽  
Thermodynamic Approach ◽  
The Sun ◽  
Radiative Balance ◽  
The Earth ◽  
Classical Models ◽  
Convective Cells

Classical models of the Sun suggest that the energy output in the early stage of its evolution was 30 percent less than today. In this context, radiative balance alone between The Sun and the Earth was not sufficient to explain the early presence of liquid water on Earth’s surface. This difficulty is called the faint young Sun paradox. Many proposals have been published to solve this paradox. In the present work, we propose an oversimplified finite-time thermodynamic approach that describes the air convective cells in the Earth atmosphere. This model introduces two atmospheric modes of thermodynamic performance: a first mode consisting in the maximization of the power output of the convective cells (maximum power regime) and a second mode that consists in maximizing a functional representing a good trade-off between power output and entropy production (the ecological regime). Within the assumptions of this oversimplified model, we present different scenarios of albedo and greenhouse effects that seem realistic to preserve liquid water on the Earth in the early stage of formation.

scholarly journals Lunar-forming impacts: processes and alternatives

2014 ◽  
Vol 372 (2024) ◽  
pp. 20130175 ◽  
Author(s):  
R. M. Canup
Keyword(s):  
Angular Momentum ◽  
Large Scale ◽  
Early Earth ◽  
The Sun ◽  
Initial Composition ◽  
High Angular Momentum ◽  
Giant Impact ◽  
Earth’S Mantle ◽  
Momentum Loss ◽  
Angular Momentum Loss

The formation of a protolunar disc by a giant impact with the early Earth is discussed, focusing on two classes of impacts: (i) canonical impacts, in which a Mars-sized impactor produces a planet–disc system whose angular momentum is comparable to that in the current Earth and Moon, and (ii) high-angular-momentum impacts, which produce a system whose angular momentum is approximately a factor of 2 larger than that in the current Earth and Moon. In (i), the disc originates primarily from impactor-derived material and thus is expected to have an initial composition distinct from that of the Earth's mantle. In (ii), a hotter, more compact initial disc is produced with a silicate composition that can be nearly identical to that of the silicate Earth. Both scenarios require subsequent processes for consistency with the current Earth and Moon: disc–planet compositional equilibration in the case of (i), or large-scale angular momentum loss during capture of the newly formed Moon into the evection resonance with the Sun in the case of (ii).

scholarly journals Swansong biospheres II: the final signs of life on terrestrial planets near the end of their habitable lifetimes

2014 ◽  
Vol 13 (3) ◽  
pp. 229-243 ◽  
Author(s):  
Jack T. O'Malley-James ◽  
Charles S. Cockell ◽  
Jane S. Greaves ◽  
John A. Raven
Keyword(s):  
Environmental Conditions ◽  
Late Stage ◽  
Cloud Cover ◽  
Main Sequence ◽  
Interaction Model ◽  
Early Earth ◽  
Sequence Evolution ◽  
The Sun ◽  
Upper Limit ◽  
Life On Earth

AbstractThe biosignatures of life on Earth do not remain static, but change considerably over the planet's habitable lifetime. Earth's future biosphere, much like that of the early Earth, will consist of predominantly unicellular microorganisms due to the increased hostility of environmental conditions caused by the Sun as it enters the late stage of its main sequence evolution. Building on previous work, the productivity of the biosphere is evaluated during different stages of biosphere decline between 1 and 2.8 Gyr from present. A simple atmosphere–biosphere interaction model is used to estimate the atmospheric biomarker gas abundances at each stage and to assess the likelihood of remotely detecting the presence of life in low-productivity, microbial biospheres, putting an upper limit on the lifetime of Earth's remotely detectable biosignatures. Other potential biosignatures such as leaf reflectance and cloud cover are discussed.

Redox Processes in Early Earth Accretion and in Terrestrial Bodies

Elements ◽  
2020 ◽  
Vol 16 (3) ◽  
pp. 161-166 ◽  
Author(s):  
Kevin Righter ◽  
Christopher D. K. Herd ◽  
Asmaa Boujibar
Keyword(s):  
Numerical Simulations ◽  
Liquid Water ◽  
Experimental Studies ◽  
Early Earth ◽  
Redox Processes ◽  
Natural Materials ◽  
The Earth

The Earth is a unique rocky planet with liquid water at the surface and an oxygen-rich atmosphere, consequences of its particular accretion history. The earliest accreting bodies were small and could be either differentiated and undifferentiated; later larger bodies had formed cores and mantles with distinct properties. In addition, there may have been an overall trend of early reduced and later oxidized material accreting to form the Earth. This paper provides an overview—based on natural materials in our Earthbound sample collections, experimental studies on those samples, and calculations and numerical simulations of differentiation processes—of planetary accretion, core–mantle equilibration, mantle redox processes, and redox variations in Earth, Mars, and other terrestrial bodies.

scholarly journals Mimicking the Martian Hydrological Cycle: A Set-Up to Introduce Liquid Water in Vacuum

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6150
Author(s):  
Jesús Manuel Sobrado
Keyword(s):  
Liquid Water ◽  
Vacuum Chamber ◽  
Hydrological Cycle ◽  
Water Cycle ◽  
Technological Development ◽  
Extreme Environment ◽  
Moss Sample ◽  
Water Condensation ◽  
Laboratory Facility ◽  
Set Up

Liquid water is well known as the life ingredient as a solvent. However, so far, it has only been found in liquid state on this planetary surface. The aim of this experiment and technological development was to test if a moss sample is capable of surviving in Martian conditions. We built a system that simulates the environmental conditions of the red planet including its hydrological cycle. This laboratory facility enables us to control the water cycle in its three phases through temperature, relative humidity, hydration, and pressure with a system that injects water droplets into a vacuum chamber. We successfully simulated the daytime and nighttime of Mars by recreating water condensation and created a layer of superficial ice that protects the sample against external radiation and minimizes the loss of humidity due to evaporation to maintain a moss sample in survival conditions in this extreme environment. We performed the simulations with the design and development of different tools that recreate Martian weather in the MARTE simulation chamber.

scholarly journals Habitability of the early Earth: Liquid water under a faint young Sun facilitated by strong tidal heating due to a nearby Moon

2020 ◽  
Author(s):  
René Heller ◽  
Jan-Peter Duda ◽  
Max Winkler ◽  
Joachim Reitner ◽  
Laurent Gizon
Keyword(s):  
Liquid Water ◽  
Early Earth ◽  
Tidal Heating

scholarly journals Albrecht Dürer and the Beginnings of Czech Illustration

2019 ◽  
Vol 64 (1-2) ◽  
pp. 45-55
Author(s):  
Petr Voit
Keyword(s):  
19Th Century ◽  
16Th Century ◽  
The Sun ◽  
Graphic Art ◽  
Holy Trinity ◽  
Book Printing ◽  
John The Baptist ◽  
The Poor ◽  
The 19Th Century ◽  
Popular Books

This article deals with printed graphic sheets, cycles and illustrations by Albrecht Dürer, which penetrated into book printing in the Czech language (Nuremberg) and in Bohemia (Prague, Litomyšl) through original printing blocks as well as copies in the first half of the 16th century. Dürer’s graphic sheets were distributed by the Nuremberg printers Hieronymus Höltzel (1509, 1511) and Friedrich Peypus (1534), the Litomyšl printing workshop working for the Unity of the Brethren (Unitas fratrum) in Litomyšl (1520), and the so-called Severin Workshop, connected to the Prague printing workshop of Pavel Severin of Kapí Hora (1529, 1539). Eleven works of religious character associated with Dürer have been discovered among Czech illustrations so far – they were made by means of seven original printing blocks and four copies, which is not so much. In this respect, Dürer was greatly surpassed by his Nuremberg successor, Erhard Schön. After Schön died in 1542, the printer Jan Günther received roughly one quarter of workshop printing blocks (approximately 340 pieces). Two years later, he moved them to Moravia, where they were coming to life in Prostějov, then in Olomouc and eventually in popular books, brochures and broadsides from Skalice until the end of the 19th century. Dürer’s printing blocks that functioned in the context of Czech book printing depict: [1a] the Nativity, [2c] the apocalyptic Woman Clothed with the Sun, and [5a–e] the Saints (James the Greater, Peter, John the Evangelist, John the Baptist and Judas Thaddaeus). The following subjects were copied: [2b] the apocalyptic Woman Clothed with the Sun, [3b] Christ in the Garden of Gethsemane, [4c] Two Angels (Geniuses), and [6b] the Holy Trinity. The woodcut copies are not exact replicas. The poor artistry and craftsmanship of the copyists, whose names are not known, led to the omission of details. The problem is that the copyists were not trying to present Dürer’s graphic art but needed a cheap and simple acquisition of the biblical scene required. More detailed information on the printing blocks and copies is available in the catalogue attached.

scholarly journals Detecting and Searching for subglacial lakes through airborne radio-echo sounding in Princess Elizabeth Land (PEL), Antarctica

2020 ◽  
Vol 163 ◽  
pp. 04002
Author(s):  
Xiangbin Cui ◽  
Shinan Lang ◽  
Jingxue Guo ◽  
Bo Sun
Keyword(s):  
Remote Sensing ◽  
Ice Sheet ◽  
Extreme Environment ◽  
Ice Flow ◽  
Preliminary Results ◽  
Lake Vostok ◽  
Subglacial Lake ◽  
Radio Echo Sounding ◽  
Subglacial Lakes ◽  
Echo Sounding

Over 400 subglacial lakes were discovered in Antarctica through radio-echo sounding (RES) method and remote sensing. Subglacial lakes have significance in lubricating ice-bedrock interface and enhancing ice flow. Moreover, ancient lives may exist in the extreme environment. Since 2015, the “Snow Eagle 601” BT-67 airborne platform has been deployed and applied to map ice sheet and bedrock of Princess Elizabeth Land. One of great motivations of airborne surveys is to detect and search for subglacial lakes in the region. In this paper, we provided preliminary results of RES over both old and new discovered lakes, including Lake Vostok, a potential second large subglacial lake and other lakes beneath interior of the ice sheet in Antarctica.

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