Six ‘Must-Have’ Minerals for Life’s Emergence: Olivine, Pyrrhotite, Bridgmanite, Serpentine, Fougerite and Mackinawite

Life cannot emerge on a planet or moon without the appropriate electrochemical disequilibria and the minerals that mediate energy-dissipative processes. Here, it is argued that four minerals, olivine ([Mg>Fe]2SiO4), bridgmanite ([Mg,Fe]SiO3), serpentine ([Mg,Fe,]2-3Si2O5[OH)]4), and pyrrhotite (Fe(1−x)S), are an essential requirement in planetary bodies to produce such disequilibria and, thereby, life. Yet only two minerals, fougerite ([Fe2+6xFe3+6(x−1)O12H2(7−3x)]2+·[(CO2−)·3H2O]2−) and mackinawite (Fe[Ni]S), are vital—comprising precipitate membranes—as initial “free energy” conductors and converters of such disequilibria, i.e., as the initiators of a CO2-reducing metabolism. The fact that wet and rocky bodies in the solar system much smaller than Earth or Venus do not reach the internal pressure (≥23 GPa) requirements in their mantles sufficient for producing bridgmanite and, therefore, are too reduced to stabilize and emit CO2—the staple of life—may explain the apparent absence or negligible concentrations of that gas on these bodies, and thereby serves as a constraint in the search for extraterrestrial life. The astrobiological challenge then is to search for worlds that (i) are large enough to generate internal pressures such as to produce bridgmanite or (ii) boast electron acceptors, including imported CO2, from extraterrestrial sources in their hydrospheres.

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Prospects for Life on Other Planets

Assembling Life ◽

10.1093/oso/9780190646387.003.0017 ◽

2019 ◽

Author(s):

David W. Deamer

Keyword(s):

Solar System ◽

Origin Of Life ◽

Hydrothermal Vents ◽

European Space Agency ◽

Extraterrestrial Life ◽

Major Question ◽

Space Agency ◽

Planetary Bodies ◽

The Origin Of Life ◽

Alternative Scenarios

This book describes a hypothetical process in which populations of protocells can spontaneously assemble and begin to grow and proliferate by energy- dependent polymerization. This might seem to be just an academic question pursued by a few dozen researchers as a matter of curiosity, but in the past three decades advances in engineering have reached a point where both NASA and the European Space Agency (ESA) routinely send spacecraft to other planetary objects in our solar system. A major question being pursued is whether life has emerged elsewhere than on Earth. The limited funds available to support such missions require decisions to be made about target priorities that are guided by judgment calls. These in turn depend on plausible scenarios related to the origin of life on habitable planetary surfaces. We know that other planetary bodies in our solar system have had or do have conditions that would permit microbial life to exist and perhaps even to begin. By a remarkable coincidence, the two most promising objects for extraterrestrial life happen to represent the two alternative scenarios described in this book: An origin of life in conditions of hydrothermal vents or an origin in hydrothermal fields. This final chapter will explore how these alternative views can guide our judgment about where to send future space missions designed as life-detection missions. Questions to be addressed: What is meant by habitability? Which planetary bodies are plausible sites for the origin of life? How do the hypotheses described in this book relate to those sites? There is healthy public interest in how life begins and whether it exists elsewhere in our solar system or on the myriad exoplanets now known to orbit other stars. This has fueled a series of films, television programs, and science fiction novels. Most of these feature extrapolations to intelligent life but a few, such as The Andromeda Strain, explore what might happen if a pathogenic organism from space began to spread to the human population. There is a serious and sustained scientific effort—SETI, or Search for Extraterrestrial Intelligence—devoted to finding an answer to this question.

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Bayesian constraints on the origin and geology of exo-planetary material using a population of externally polluted white dwarfs

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab736 ◽

2021 ◽

Author(s):

John H D Harrison ◽

Amy Bonsor ◽

Mihkel Kama ◽

Andrew M Buchan ◽

Simon Blouin ◽

...

Keyword(s):

Solar System ◽

White Dwarf ◽

Bayesian Model ◽

Total Mass ◽

White Dwarfs ◽

Bulk Composition ◽

Planetary Systems ◽

The Moon ◽

Planetary Bodies ◽

Nearby Stars

Abstract White dwarfs that have accreted planetary bodies are a powerful probe of the bulk composition of exoplanetary material. In this paper, we present a Bayesian model to explain the abundances observed in the atmospheres of 202 DZ white dwarfs by considering the heating, geochemical differentiation, and collisional processes experienced by the planetary bodies accreted, as well as gravitational sinking. The majority (>60%) of systems are consistent with the accretion of primitive material. We attribute the small spread in refractory abundances observed to a similar spread in the initial planet-forming material, as seen in the compositions of nearby stars. A range in Na abundances in the pollutant material is attributed to a range in formation temperatures from below 1,000 K to higher than 1,400 K, suggesting that pollutant material arrives in white dwarf atmospheres from a variety of radial locations. We also find that Solar System-like differentiation is common place in exo-planetary systems. Extreme siderophile (Fe, Ni or Cr) abundances in 8 systems require the accretion of a core-rich fragment of a larger differentiated body to at least a 3σ significance, whilst one system shows evidence that it accreted a crust-rich fragment. In systems where the abundances suggest that accretion has finished (13/202), the total mass accreted can be calculated. The 13 systems are estimated to have accreted masses ranging from the mass of the Moon to half that of Vesta. Our analysis suggests that accretion continues for 11Myrs on average.

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On the relationship between long-period comets and large trans-Neptunian planetary bodies

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316012692 ◽

2016 ◽

Vol 12 (S325) ◽

pp. 263-265

Author(s):

Rustam Guliyev ◽

Ayyub Guliyev

Keyword(s):

Solar System ◽

Numerical Integration ◽

Dynamical Evolution ◽

Integration Methods ◽

Long Period ◽

Planetary Bodies ◽

Numerical Integration Methods ◽

Relationship Of ◽

The Relationship

AbstractIn the present work we investigate the possible relationship of long-period comets with five large and distant trans-Neptunian bodies (Sedna, Eris, 2007 OR10, 2012 VP113and 2008 ST291) in order to determine the probability of the transfer of a part of these kind of comets to the inner of the Solar System. To identify such relationships, we studied the relative positions of the comet orbits and listed TNOs. Using numerical integration methods, we examined dynamical evolution of the comets and have found one encounter of comet C/1861J1 and Eris.

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The Gibbs free energy of formation of halogenated benzenes, benzoates and phenols and their potential role as electron acceptors in anaerobic environments

Biodegradation ◽

10.1007/s10532-014-9710-5 ◽

2014 ◽

Vol 26 (1) ◽

pp. 15-27 ◽

Cited By ~ 18

Author(s):

Jan Dolfing ◽

Igor Novak

Keyword(s):

Free Energy ◽

Gibbs Free Energy ◽

Potential Role ◽

Electron Acceptors ◽

Halogenated Benzenes ◽

Free Energy Of Formation ◽

Energy Of Formation

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Scaling properties of planetary calderas and terrestrial volcanic eruptions

Nonlinear Processes in Geophysics ◽

10.5194/npg-19-585-2012 ◽

2012 ◽

Vol 19 (6) ◽

pp. 585-593 ◽

Cited By ~ 2

Author(s):

L. Sanchez ◽

R. Shcherbakov

Keyword(s):

Solar System ◽

Scaling Law ◽

Geographical Location ◽

Internal Heat ◽

Volcanic Eruptions ◽

Scaling Analysis ◽

Scaling Properties ◽

Caldera Formation ◽

Planetary Bodies ◽

Terrestrial Planetary Bodies

Abstract. Volcanism plays an important role in transporting internal heat of planetary bodies to their surface. Therefore, volcanoes are a manifestation of the planet's past and present internal dynamics. Volcanic eruptions as well as caldera forming processes are the direct manifestation of complex interactions between the rising magma and the surrounding host rock in the crust of terrestrial planetary bodies. Attempts have been made to compare volcanic landforms throughout the solar system. Different stochastic models have been proposed to describe the temporal sequences of eruptions on individual or groups of volcanoes. However, comprehensive understanding of the physical mechanisms responsible for volcano formation and eruption and more specifically caldera formation remains elusive. In this work, we propose a scaling law to quantify the distribution of caldera sizes on Earth, Mars, Venus, and Io, as well as the distribution of calderas on Earth depending on their surrounding crustal properties. We also apply the same scaling analysis to the distribution of interevent times between eruptions for volcanoes that have the largest eruptive history as well as groups of volcanoes on Earth. We find that when rescaled with their respective sample averages, the distributions considered show a similar functional form. This result implies that similar processes are responsible for caldera formation throughout the solar system and for different crustal settings on Earth. This result emphasizes the importance of comparative planetology to understand planetary volcanism. Similarly, the processes responsible for volcanic eruptions are independent of the type of volcanism or geographical location.

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Extraterrestrial life in the Solar System?

The Search for Life Continued ◽

10.1007/978-0-387-76559-4_6 ◽

2008 ◽

pp. 71-86

Keyword(s):

Solar System ◽

Extraterrestrial Life

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Advances in Cosmochemistry Enabled by Antarctic Meteorites

Annual Review of Earth and Planetary Sciences ◽

10.1146/annurev-earth-082719-055815 ◽

2020 ◽

Vol 48 (1) ◽

pp. 233-258

Author(s):

Meenakshi Wadhwa ◽

Timothy J. McCoy ◽

Devin L. Schrader

Keyword(s):

Solar System ◽

Planetary Science ◽

The Moon ◽

Origin And Evolution ◽

Lunar Meteorite ◽

Planetary Bodies ◽

The Antarctic ◽

Melt Pockets ◽

Scientific Advances

At present, meteorites collected in Antarctica dominate the total number of the world's known meteorites. We focus here on the scientific advances in cosmochemistry and planetary science that have been enabled by access to, and investigations of, these Antarctic meteorites. A meteorite recovered during one of the earliest field seasons of systematic searches, Elephant Moraine (EET) A79001, was identified as having originated on Mars based on the composition of gases released from shock melt pockets in this rock. Subsequently, the first lunar meteorite, Allan Hills (ALH) 81005, was also recovered from the Antarctic. Since then, many more meteorites belonging to these two classes of planetary meteorites, as well as other previously rare or unknown classes of meteorites (particularly primitive chondrites and achondrites), have been recovered from Antarctica. Studies of these samples are providing unique insights into the origin and evolution of the Solar System and planetary bodies. ▪ Antarctic meteorites dominate the inventory of the world's known meteorites and provide access to new types of planetary and asteroidal materials. ▪ The first meteorites recognized to be of lunar and martian origin were collected from Antarctica and provided unique constraints on the evolution of the Moon and Mars. ▪ Previously rare or unknown classes of meteorites have been recovered from Antarctica and provide new insights into the origin and evolution of the Solar System.

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Stress and flexibility factors for multi-mitred pipe bends subjected to internal pressure combined with external loadings

Journal of Strain Analysis ◽

10.1243/03093247v072097 ◽

1972 ◽

Vol 7 (2) ◽

pp. 97-108 ◽

Cited By ~ 7

Author(s):

M P Bond ◽

R Kitching

Keyword(s):

Internal Pressure ◽

Large Diameter ◽

Pipe Bend ◽

Bending Tests ◽

Bending Load ◽

Out Of Plane ◽

Thin Walled ◽

Plane Bending ◽

Internal Pressures ◽

Stress Patterns

The stress analysis of a multi-mitred pipe bend when subjected to an internal pressure and a simultaneous in-plane or out-of-plane bending load has been developed. Stress patterns and flexibility factors calculated by this analysis are compared with experimental results from a large-diameter, thin-walled, three-weld, 90° multi-mitred bend which was subjected to in-plane bending tests at various internal pressures.

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Erosive Hit-and-Run Impact Events: Debris Unbound

Proceedings of the International Astronomical Union ◽

10.1017/s1743921315009679 ◽

2015 ◽

Vol 10 (S318) ◽

pp. 9-15

Author(s):

Gal Sarid ◽

Sarah T. Stewart ◽

Zoë M. Leinhardt

Keyword(s):

Solar System ◽

Asteroid Belt ◽

Mass Composition ◽

Residual Velocity ◽

Processed Material ◽

Planetary Bodies ◽

Hit And Run ◽

Main Asteroid Belt ◽

Impact Events

AbstractErosive collisions among planetary embryos in the inner solar system can lead to multiple remnant bodies, varied in mass, composition and residual velocity. Some of the smaller, unbound debris may become available to seed the main asteroid belt. The makeup of these collisionally produced bodies is different from the canonical chondritic composition, in terms of rock/iron ratio and may contain further shock-processed material. Having some of the material in the asteroid belt owe its origin from collisions of larger planetary bodies may help in explaining some of the diversity and oddities in composition of different asteroid groups.

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