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

PalZ ◽  
2021 ◽  
Author(s):  
René Heller ◽  
Jan-Peter Duda ◽  
Max Winkler ◽  
Joachim Reitner ◽  
Laurent Gizon
Keyword(s):  
Liquid Water ◽  
Power Output ◽  
Mechanical Energy ◽  
Early Earth ◽  
Phase Lag ◽  
Geological Evidence ◽  
The Earth ◽  
Tidal Theory ◽  
Greenhouse Effects ◽  
Tidal Heating

AbstractGeological evidence suggests liquid water near the Earth’s surface as early as 4.4 gigayears ago when the faint young Sun only radiated about 70% of its modern power output. At this point, the Earth should have been a global snowball if it possessed atmospheric properties similar to those of the modern Earth. An extreme atmospheric greenhouse effect, an initially more massive Sun, release of heat acquired during the accretion process of protoplanetary material, and radioactivity of the early Earth material have been proposed as reservoirs or traps for heat. For now, the faint-young-Sun paradox persists as an important problem in our understanding of the origin of life on Earth. Here, we use the constant-phase-lag tidal theory to explore the possibility that the new-born Moon, which formed about 69 million years (Myr) after the ignition of the Sun, generated extreme tidal friction—and therefore, heat—in the Hadean and possibly the Archean Earth. We show that the Earth–Moon system has lost $${\sim }3~{\times }~10^{31}$$ ∼ 3 × 10 31  J (99% of its initial mechanical energy budget) as tidal heat. Tidal heating of $${\sim }10\,\mathrm{W\,m}^{-2}$$ ∼ 10 W m - 2 through the surface on a time scale of 100 Myr could have accounted for a temperature increase of up to $$5\,^\circ $$ 5 ∘ C on the early Earth. This heating effect alone does not solve the faint-young-Sun paradox but it could have played a key role in combination with other effects. Future studies of the interplay of tidal heating, the evolution of the solar power output, and the atmospheric (greenhouse) effects on the early Earth could help in solving the faint-young-Sun paradox.

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.

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 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 Tidal heating and the habitability of the TRAPPIST-1 exoplanets

2019 ◽  
Vol 624 ◽  
pp. A2 ◽  
Author(s):  
Vera Dobos ◽  
Amy C. Barr ◽  
László L. Kiss
Keyword(s):  
Liquid Water ◽  
Weighted Average ◽  
Heat Fluxes ◽  
Tidal Dissipation ◽  
Water Ice ◽  
The Earth ◽  
Tidal Heating ◽  
The Masses ◽  
Viscoelastic Rheology ◽  
M Dwarf

Context. New estimates of the masses and radii of the seven planets orbiting the ultracool M-dwarf TRAPPIST-1 star permit improved modelling of their compositions, heating by tidal dissipation, and removal of tidal heat by solid-state convection. Aims. Here we compute the heat flux due to insolation and tidal heating for the inner four planets. Methods. We apply a Maxwell viscoelastic rheology to compute the tidal response of the planets using the volume-weighted average of the viscosities and rigidities of the metal, rock, high-pressure ice, and liquid water/ice I layers. Results. We show that TRAPPIST-1d and e can avoid entering a runaway greenhouse state. Planet e is the most likely to support a habitable environment, with Earth-like surface temperatures and possibly liquid water oceans. Planet d also avoids a runaway greenhouse, if its surface reflectance is at least as high as that of the Earth. Planets b and c, closer to the star, have heat fluxes high enough to trigger a runaway greenhouse and to support volcanism on the surfaces of their rock layers, rendering them too warm for life. Planets f, g, and h are too far from the star to experience significant tidal heating, and likely have solid ice surfaces with possible subsurface liquid water oceans.

scholarly journals Uncertainties in tidal theory: Implications for bloated hot Jupiters

2010 ◽  
Vol 6 (S276) ◽  
pp. 248-251 ◽  
Author(s):  
Jérémy Leconte ◽  
Gilles Chabrier ◽  
Isabelle Baraffe
Keyword(s):  
Thermal Flux ◽  
Giant Planet ◽  
Theoretical Models ◽  
Mass Range ◽  
List Type ◽  
Phase Lag ◽  
Ohmic Dissipation ◽  
Tidal Theory ◽  
Strong Winds ◽  
Tidal Heating

AbstractThanks to the combination of transit photometry and radial velocity doppler measurements, we are now able to constrain theoretical models of the structure and evolution of objects in the whole mass range between icy giants and stars, including the giant planet/brown dwarf overlapping mass regime (Leconte et al. 2009). In the giant planet mass range, the significant fraction of planets showing a larger radius than predicted by the models suggests that a missing physical mechanism which is either injecting energy in the deep convective zone or reducing the net outward thermal flux is taking place in these objects. Several possibilities have been suggested for such a mechanism: •downward transport of kinetic energy originating from strong winds generated at the planet's surface (Showman & Guillot 2002),•enhanced opacity sources in hot-Jupiter atmospheres (Burrows et al. 2007),•ohmic dissipation in the ionized atmosphere (Batygin & Stevenson 2010),•(inefficient) layered or oscillatory convection in the planet's interior (Chabrier & Baraffe 2007),•Tidal heating due to circularization of the orbit, as originally suggested by Bodenheimer, Lin & Mardling (2001). Here we first review the differences between current models of tidal evolution and their uncertainties. We then revisit the viability of the tidal heating hypothesis using a tidal model which treats properly the highly eccentric and misaligned orbits commonly encountered in exoplanetary systems. We stress again that the low order expansions in eccentricity often used in constant phase lag tidal models (i.e. constant Q) necessarily yields incorrect results as soon as the (present or initial) eccentricity exceeds ~ 0.2, as can be rigorously demonstrated from Kepler's equations.

Planet Earth – our oasis in space

2004 ◽  
Vol 12 (1) ◽  
pp. 111-119
Author(s):  
SIEGFRIED J. BAUER
Keyword(s):  
Magnetic Field ◽  
Solar System ◽  
Internal Structure ◽  
Solid Surface ◽  
Liquid Water ◽  
Atmospheric Environment ◽  
Suitable Habitat ◽  
The Earth

Planet Earth is unique in our solar system as an abode of life. In contrast to its planetary neighbours, the presence of liquid water, a benign atmospheric environment, a solid surface and an internal structure providing a protective magnetic field make it a suitable habitat for man. While natural forces have shaped the Earth over millennia, man through his technological prowess may become a threat to this oasis of life in the solar system.

The Effects of Turbulence Length Scale on the Performance of Piezoelectric Harvesters

2015 ◽  
Author(s):  
Yiannis Andreopoulos ◽  
Amir H. Danesh-Yazdi ◽  
Oleg Goushcha ◽  
Niell Elvin
Keyword(s):  
Turbulent Flows ◽  
Power Output ◽  
Isotropic Turbulence ◽  
Spatial Scales ◽  
Mechanical Energy ◽  
Relative Size ◽  
Analytical Description ◽  
Length Scale ◽  
Linear Effect ◽  
Turbulence Length

Turbulent flows carry mechanical energy distributed over a range of temporal and spatial scales and their interaction with a thin immersed piezoelectric beam results in a strain field which generates electrical charge. This energy harvesting method can be used for developing self-powered electronic devices such as flow sensors. In the present experimental work, various energy harvesters were placed in a turbulent boundary layer or inside a decaying flow field of homogeneous and isotropic turbulence. The role of large instantaneous turbulent structures in this rather complex fluid-structure interaction is discussed in interpreting the electrical output results. The forces acting on the vibrating beams have been measured dynamically and a theory has been developed which incorporates the effects of mean local velocity, turbulence intensity, the relative size of the beam’s length to the integral length scale of turbulence, the structural properties of the beam and the electrical properties of the active piezoelectric layer to provide reasonable estimates of the mean electrical power output. Experiments have been carried out in which these fluidic harvesters are immersed first in inhomogeneous turbulence like that encountered in boundary layers developing over solid walls and homogeneous and isotopic turbulence for which a simplified analytical description exists. It was found that there is a non-linear effect of turbulence length scales on the power output of the fluidic harvesters.

The impact of cloud inhomogeneities on the Earth radiation budget: the 14 October 1989 I.C.E. convective cloud case study

1994 ◽  
Vol 12 (2/3) ◽  
pp. 240-253 ◽  
Author(s):  
F. Parol ◽  
J. C. Buriez ◽  
D. Crétel ◽  
Y. Fouquart
Keyword(s):  
Aspect Ratio ◽  
Water Content ◽  
Liquid Water ◽  
Convective Cloud ◽  
Liquid Water Content ◽  
Radiation Budget ◽  
The Earth ◽  
Earth Radiation Budget ◽  
The Impact ◽  
Earth Radiation

Abstract. Through their multiple interactions with radiation, clouds have an important impact on the climate. Nonetheless, the simulation of clouds in climate models is still coarse. The present evolution of modeling tends to a more realistic representation of the liquid water content; thus the problem of its subgrid scale distribution is crucial. For a convective cloud field observed during ICE 89, Landsat TM data (resolution: 30m) have been analyzed in order to quantify the respective influences of both the horizontal distribution of liquid water content and cloud shape on the Earth radiation budget. The cloud field was found to be rather well-represented by a stochastic distribution of hemi-ellipsoidal clouds whose horizontal aspect ratio is close to 2 and whose vertical aspect ratio decreases as the cloud cell area increases. For that particular cloud field, neglecting the influence of the cloud shape leads to an over-estimate of the outgoing longwave flux; in the shortwave, it leads to an over-estimate of the reflected flux for high solar elevations but strongly depends on cloud cell orientations for low elevations. On the other hand, neglecting the influence of cloud size distribution leads to systematic over-estimate of their impact on the shortwave radiation whereas the effect is close to zero in the thermal range. The overall effect of the heterogeneities is estimated to be of the order of 10 W m-2 for the conditions of that Landsat picture (solar zenith angle 65°, cloud cover 70%); it might reach 40 W m-2 for an overhead sun and overcast cloud conditions.

scholarly journals VII.—On the Mechanical Energies of the Solar System

1857 ◽  
Vol 21 (1) ◽  
pp. 63-80 ◽  
Author(s):  
William Thomson
Keyword(s):  
Solar System ◽  
Mechanical Energy ◽  
Mechanical Power ◽  
Direct Perception ◽  
Organic Life ◽  
The Earth

The mutual actions and motions of the heavenly bodies have long been regarded as the grandest phenomena of mechanical energy in nature. Their light has been seen, and their heat has been felt, without the slightest suspicion that we had thus a direct perception of mechanical energy at all. Even after it has been shewn that the almost inconceivably minute fraction of the Sun's heat and light reaching the earth is the source of energy from which all the mechanical actions of organic life, and nearly every motion of inorganic nature at its surface, are derived, the energy of this source has been scarcely thought of as a development of mechanical power.

The Early Earth: An Ocean with Volcanoes

2019 ◽  
Author(s):  
David W. Deamer
Keyword(s):  
Graduate Student ◽  
North Pole ◽  
Equal Probability ◽  
Early Earth ◽  
Planetary Evolution ◽  
The North ◽  
Tectonic Processes ◽  
The Earth ◽  
Life On Mars ◽  
Geophysical Processes

Malcolm Walter was talking about the Pilbara region of Western Australia where some of the oldest known biosignatures of ancient life, in the form of extensive fossilized stromatolites, are preserved. The first potential stromatolite was discovered by graduate student John Dunlop, who was studying barite deposits at the North Pole Dome. Roger Buick went on to investigate the biogenicity of the stromatolites for his PhD (Buick, 1985) and Dunlop, Buick, and Walter published their results (Walter et al., 1980). In a prescient paper, Walter and Des Marais (1993) proposed that the ancient stromatolite fossils could guide the search for life on Mars. I have walked with Malcolm Walter through the Dresser formation where the fossils were found. It is humbling to realize that if time passed at a thousand years per second, it would take 41 days to go back in time to the first signs of life on our planet. In any description of events that occurred some 4 billion years ago, certain assumptions must be made. I will try to make assumptions explicit throughout this book, beginning here with the geochemical and geophysical conditions prevailing on the early Earth and Mars. I am including Mars not as an afterthought but because both planets had liquid water 4 billion years ago. Most of our understanding of planetary evolution comes from observations of our own planet, but it is now clear that the Earth and Mars were undergoing similar geophysical processes during the first billion years of the solar system’s existence, with an equal probability that life could begin on either planet. In a sense, the surface of Mars is a geological fossil that has preserved evidence of what was happening there at the same time that life began on the Earth. For instance, Martian volcanoes offer direct, observable evidence that volcanism was occurring nearly 4 billion years ago; making it plausible that similar volcanism was common on Earth even though the evidence has been completely erased by geological and tectonic processes.

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