The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
M Cuntz - One of the best experts on this subject based on the ideXlab platform.
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s type and p type Habitability in stellar binary systems a comprehensive approach ii elliptical orbits
arXiv: Solar and Stellar Astrophysics, 2014Co-Authors: M CuntzAbstract:In the first paper of this series, a comprehensive approach has been provided for the study of S-type and P-type habitable regions in stellar binary systems, which was, however, restricted to circular orbits of the stellar components. Fortunately, a modest modification of the method also allows for the consideration of elliptical orbits, which of course entails a much broader range of applicability. This augmented method is presented here, and numerous applications are conveyed. In alignment with Paper I, the selected approach considers a variety of aspects, which comprise the consideration of a joint constraint including orbital stability and a habitable region for a possible system planet through the stellar radiative energy fluxes ("radiative habitable zone"; RHZ). The devised method is based on a combined formalism for the assessment of both S-type and P-type Habitability; in particular, mathematical criteria are deduced for which kinds of systems S-type and P-type habitable zones are realized. If the RHZs are truncated by the additional constraint of orbital stability, the notation of ST-type and PT-type Habitability applies. In comparison to the circular case, it is found that in systems of higher eccentricity, the range of the RHZs is significantly reduced. Moreover, for a considerable number of models, the orbital stability constraint also reduces the range of S-type and P-type Habitability. Nonetheless, S-, P-, ST-, and PT-type Habitability is identified for a considerable set of system parameters. The method as presented is utilized for BinHab, an online code available at The University of Texas at Arlington.
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s type and p type Habitability in stellar binary systems a comprehensive approach i method and applications
The Astrophysical Journal, 2013Co-Authors: M CuntzAbstract:A comprehensive approach is provided for the study of both S-type and P-type Habitability in stellar binary systems, which in principle can also be expanded to systems of higher order. P-type orbits occur when the planet orbits both binary components, whereas in the case of S-type orbits, the planet orbits only one of the binary components with the second component considered a perturbator. The selected approach encapsulates a variety of different aspects, which include: (1) the consideration of a joint constraint, including orbital stability and a habitable region for a putative system planet through the stellar radiative energy fluxes (radiative habitable zone; RHZ), needs to be met; (2) the treatment of conservative, general, and extended zones of Habitability for the various systems as defined for the solar system and beyond; (3) the provision of a combined formalism for the assessment of both S-type and P-type Habitability; in particular, mathematical criteria are presented for the kind of system in which S-type and P-type Habitability is realized; (4) applications of the attained theoretical approach to standard (theoretical) main-sequence stars. In principle, five different cases of Habitability are identified, which are S-type and P-type Habitability provided by the full extent of the RHZs; Habitability, where the RHZs are truncated by the additional constraint of planetary orbital stability (referred to as ST- and PT-type, respectively); and cases of no Habitability at all. Regarding the treatment of planetary orbital stability, we utilize the formulae of Holman & Wiegert as also used in previous studies. In this work, we focus on binary systems in circular orbits. Future applications will also consider binary systems in elliptical orbits and provide thorough comparisons to other methods and results given in the literature.
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s type and p type Habitability in stellar binary systems a comprehensive approach i method and applications
arXiv: Earth and Planetary Astrophysics, 2013Co-Authors: M CuntzAbstract:A comprehensive approach is provided to the study of both S-type and P-type Habitability in stellar binary systems, which in principle can also be expanded to systems of higher order. P-type orbits occur when the planet orbits both binary components, whereas in case of S-type orbits the planet orbits only one of the binary components with the second component considered a perturbator. The selected approach encapsulates a variety of different aspects, which include: (1) The consideration of a joint constraint including orbital stability and a habitable environment for a putative system planet through the stellar radiative energy fluxes ("radiative habitable zone"; RHZ) needs to be met. (2) The treatment of conservative, general and extended zones of Habitability for the various systems as defined for the Solar System and beyond. (3) The providing of a combined formalism for the assessment of both S-type and P-type Habitability; in particular, mathematical criteria are presented for which kind of system S-type and P-type Habitability is realized. (4) Applications of the attained theoretical approach to standard (theoretical) main-sequence stars. In principle, five different cases of Habitability are identified, which are: S-type and P-type Habitability provided by the full extent of the RHZs; Habitability, where the RHZs are truncated by the additional constraint of planetary orbital stability (referred to as ST and PT-type, respectively); and cases of no Habitability at all. Regarding the treatment of planetary orbital stability, we utilize the formulae of Holman & Wiegert (1999) [AJ 117, 621], as also used by previous studies. In this work we focus on binary systems in circular orbits. Future applications will also consider binary systems in elliptical orbits and provide thorough comparisons to other methods and results given in the literature.
Jun Korenaga - One of the best experts on this subject based on the ideXlab platform.
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Plate tectonics and planetary Habitability: current status and future challenges
Annals of the New York Academy of Sciences, 2012Co-Authors: Jun KorenagaAbstract:Plate tectonics is one of the major factors affecting the potential Habitability of a terrestrial planet. The physics of plate tectonics is, however, still far from being complete, leading to considerable uncertainty when discussing planetary Habitability. Here, I summarize recent developments on the evolution of plate tectonics on Earth, which suggest a radically new view on Earth dynamics: convection in the mantle has been speeding up despite its secular cooling, and the operation of plate tectonics has been facilitated throughout Earth's history by the gradual subduction of water into an initially dry mantle. The role of plate tectonics in planetary Habitability through its influence on atmospheric evolution is still difficult to quantify, and, to this end, it will be vital to better understand a coupled core-mantle-atmosphere system in the context of solar system evolution.
Frances Westall - One of the best experts on this subject based on the ideXlab platform.
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Creating Habitable Zones, at all Scales, from Planets to Mud Micro-Habitats, on Earth and on Mars
Space Science Reviews, 2007Co-Authors: Euan Nisbet, Kevin Zahnle, M. V. Gerasimov, Jörn Helbert, Ralf Jaumann, Beda A. Hofmann, Karim Benzerara, Frances WestallAbstract:The factors that create a habitable planet are considered at all scales, from planetary inventories to micro-habitats in soft sediments and intangibles such as habitat linkage. The possibility of Habitability first comes about during accretion, as a product of the processes of impact and volatile inventory history. To create Habitability water is essential, not only for life but to aid the continual tectonic reworking and erosion that supply key redox contrasts and biochemical substrates to sustain Habitability. Mud or soft sediment may be a biochemical prerequisite, to provide accessible substrate and protection. Once life begins, the habitat is widened by the activity of life, both by its management of the greenhouse and by partitioning reductants (e.g. dead organic matter) and oxidants (including waste products). Potential Martian habitats are discussed: by comparison with Earth there are many potential environmental settings on Mars in which life may once have occurred, or may even continue to exist. The long-term evolution of Habitability in the Solar System is considered.
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Creating Habitable Zones, at all Scales, from Planets to Mud Micro-Habitats, on Earth and on Mars
Space Sci Rev, 2007Co-Authors: Euan Nisbet, Kevin Zahnle, M. V. Gerasimov, Jörn Helbert, Ralf Jaumann, Karim Benzerara, Beda A. Hofmann, Frances WestallAbstract:The factors that create a habitable planet are considered at all scales, from plan- etary inventories to micro-habitats in soft sediments and intangibles such as habitat link- age. The possibility of Habitability first comes about during accretion, as a product of the processes of impact and volatile inventory history. To create Habitability water is essential, not only for life but to aid the continual tectonic reworking and erosion that supply key redox contrasts and biochemical substrates to sustain Habitability. Mud or soft sediment may be a biochemical prerequisite, to provide accessible substrate and protection. Once life begins, the habitat is widened by the activity of life, both by its management of the greenhouse and
Özgür Karatekin - One of the best experts on this subject based on the ideXlab platform.
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Geoscience for Understanding Habitability in the Solar System and Beyond
Space Science Reviews, 2019Co-Authors: Véronique Dehant, Vera Dobos, Cedric Gillmann, Dennis Höning, Emmanuelle J. Javaux, J L Grenfell, Vinciane Debaille, Steven Goderis, Fabrice Gaillard, Özgür KaratekinAbstract:This paper reviews Habitability conditions for a terrestrial planet from the point of view of geosciences. It addresses how interactions between the interior of a planet or a moon and its atmosphere and surface (including hydrosphere and biosphere) can affect Habitability of the celestial body. It does not consider in detail the role of the central star but focusses more on surface conditions capable of sustaining life. We deal with fundamental issues of planetary Habitability, i.e. the environmental conditions capable of sustaining life, and the above-mentioned interactions can affect the Habitability of the celestial body.We address some hotly debated questions including: How do core and mantle affect the evolution and Habitability of planets?What are the consequences of mantle overturn on the evolution of the interior and atmosphere?What is the role of the global carbon and water cycles?What influence do comet and asteroid impacts exert on the evolution of the planet?How does life interact with the evolution of the Earth’s geosphere and atmosphere?How can knowledge of the solar system geophysics and Habitability be applied to exoplanets?In addition, we address the identification of preserved life tracers in the context of the interaction of life with planetary evolution.
I. Ribas - One of the best experts on this subject based on the ideXlab platform.
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Astrophysical Conditions for Planetary Habitability
Protostars and Planets VI, 2014Co-Authors: Manuel Güdel, Helmut Lammer, Rudolf Dvorak, Nikolay Erkaev, James F. Kasting, Maxim L. Khodachenko, Elke Pilat-lohinger, Heike Rauer, I. Ribas, Brian E. WoodAbstract:With the discovery of hundreds of exoplanets and a potentially huge number of Earth-like planets waiting to be discovered, the conditions for their Habitability have become a focal point in exoplanetary research. The classical picture of habitable zones primarily relies on the stellar flux allowing liquid water to exist on the surface of an Earth-like planet with a suitable atmosphere. However, numerous further stellar and planetary properties constrain Habitability. Apart from ”geophysical” processes depending on the internal structure and composition of a planet, a complex array of astrophysical factors additionally determine Habitability. Among these, variable stellar UV, EUV, and X-ray radiation, stellar and interplanetary magnetic fields, ionized winds, and energetic particles control the constitution of upper planetary atmospheres and their physical and chemical evolution. Shortand long-term stellar variability necessitates full time-dependent studies to understand planetary Habitability at any point in time. Furthermore, dynamical effects in planetary systems and transport of water to Earth-like planets set fundamentally important constraints. We will review these astrophysical conditions for Habitability under the crucial aspects of the long-term evolution of stellar properties, the consequent extreme conditions in the early evolutionary phase of planetary systems, and the important interplay between properties of the host star and its planets.
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stellar aspects of Habitability characterizing target stars for terrestrial planet finding missions
Astrobiology, 2010Co-Authors: Lisa Kaltenegger, I. Ribas, C Eiroa, Francesco Paresce, Martin Leitzinger, P Odert, A Hanslmeier, Malcolm Fridlund, H Lammer, Charles BeichmanAbstract:We present and discuss the criteria for selecting potential target stars suitable for the search for Earth-like planets, with a special emphasis on the stellar aspects of Habitability. Missions that search for terrestrial exoplanets will explore the presence and Habitability of Earth-like exoplanets around several hundred nearby stars, mainly F, G, K, and M stars. The evaluation of the list of potential target systems is essential in order to develop mission concepts for a search for terrestrial exoplanets. Using the Darwin All Sky Star Catalogue (DASSC), we discuss the selection criteria, configuration-dependent subcatalogues, and the implication of stellar activity for Habitability.
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Stellar Aspects of Habitability: Characterizing Target Stars for Terrestrial Planet Search Missions
Astrobiology, 2010Co-Authors: L. Kaltenegger, I. Ribas, C Eiroa, Francesco Paresce, Martin Leitzinger, P Odert, A Hanslmeier, Malcolm Fridlund, H Lammer, Franck SelsisAbstract:In this paper we present and discuss the criteria for selecting potential target stars suitable for the search for Earth like planets, with a special emphasis on the stellar aspects of Habitability. Missions that search for terrestrial exoplanets will explore the presence and Habitability of Earth-like exoplanets around several hundred nearby stars, mainly F, G, K, and M stars. The evaluation of the list of potential target systems in order to develop mission concepts for a search for Terrestrial Exoplanets is essential. Using the Darwin All Sky Star Catalogue (DASSC), we discuss the selection criteria, configuration dependent sub-catalogues and the implication of stellar activity for Habitability.
