A Limited Habitable Zone for Complex Life

  title={A Limited Habitable Zone for Complex Life},
  author={Edward W. Schwieterman and Christopher T. Reinhard and Stephanie L. Olson and Chester E. Harman and Timothy W. Lyons},
  journal={The Astrophysical Journal},
The habitable zone (HZ) is commonly defined as the range of distances from a host star within which liquid water, a key requirement for life, may exist on a planet's surface. Substantially more CO2 than present in Earth's modern atmosphere is required to maintain clement temperatures for most of the HZ, with several bars required at the outer edge. However, most complex aerobic life on Earth is limited by CO2 concentrations of just fractions of a bar. At the same time, most exoplanets in the… 

Figures and Tables from this paper

A Complex Life Habitable Zone Based On Lipid Solubility Theory
An advanced energy balance model is used to show that such an HZ would be considerably wider than originally predicted given revised CO 2 limits and N 2 respiration limits for complex life, and defines this CLHZ using lipid solubility theory, diving data, and results from animal laboratory experiments.
Habitable zone predictions and how to test them.
The habitable zone (HZ) is the region around a star(s) where standing bodies of water could exist on the surface of a rocky planet. The classical HZ definition makes a number of assumptions common to
Characterizing Exoplanet Habitability
Habitability is a measure of an environment's potential to support life, and a habitable exoplanet supports liquid water on its surface. However, a planet's success in maintaining liquid water on its
Efficiency of the oxygenic photosynthesis on Earth-like planets in the habitable zone
Oxygenic photosynthesis is themost important biochemical process in Earth biosphere and likely very common on other habitable terrestrial planets, given the general availability of its input chemical
The subsurface habitability of small, icy exomoons
Context. Assuming our Solar System as typical, exomoons may outnumber exoplanets. If their habitability fraction is similar, they would thus constitute the largest portion of habitable real estate in
Habitability and Spectroscopic Observability of Warm M-dwarf Exoplanets Evaluated with a 3D Chemistry-Climate Model
Planets residing in circumstellar habitable zones (CHZs) offer our best opportunities to test hypotheses of life's potential pervasiveness and complexity. Constraining the precise boundaries of
Implications of Abiotic Oxygen Buildup for Earth-like Complex Life
  • M. Lingam
  • Physics
    The Astronomical Journal
  • 2020
The constraints imposed by O$_2$ on Earth-like complex life are invoked to explore whether worlds with abiotic O-2$ inventories can harbor such organisms, and it is suggested that worlds that receive time-averaged X-ray and extreme ultraviolet fluxes that are 10 times higher than Earth might not be capable of hosting complex lifeforms.
Oxygen False Positives on Habitable Zone Planets Around Sun‐Like Stars
Oxygen is a promising exoplanet biosignature due to the evolutionary advantage conferred by harnessing starlight for photosynthesis, and the apparent low likelihood of maintaining oxygen‐rich
Triggering a Climate Change Dominated “Anthropocene”: Is It Common among Exocivilizations?
We seek to model the coupled evolution of a civilization and its host planet through the era when energy harvesting by the civilization drives the planet into new and adverse climate states. In this
Theoretical studies of comets in the 55 Cancri system
We present orbital integrations for various Jupiter family comets (JFCs) in the 55 Cancri system. This star is known to possess (at least) five planets with masses ranging from super-Earth to


A Methane Extension to the Classical Habitable Zone
The habitable zone (HZ) is the circumstellar region where standing bodies of liquid water could exist on the surface of a rocky planet. Conventional definitions assume that CO2 and H2O are the only
Why O2 is required by complex life on habitable planets and the concept of planetary "oxygenation time".
It is argued that the oxygenation time is likely to be a key rate-limiting step in the evolution of complex life on other habitable planets, including Earth-like planets orbiting short-lived stars that end their main sequence lives before planetary oxygenation takes place.
A Volcanic Hydrogen Habitable Zone
The classical habitable zone (HZ) is the circular region around a star in which liquid water could exist on the surface of a rocky planet. The outer edge of the traditional N2–CO2–H2O HZ extends out
Habitable zones around main sequence stars.
The results suggest that mid-to-early K stars should be considered along with G stars as optimal candidates in the search for extraterrestrial life.
We show that collision-induced absorption allows molecular hydrogen to act as an incondensible greenhouse gas and that bars or tens of bars of primordial H2–He mixtures can maintain surface
How rare is complex life in the Milky Way?
The number of planets predicted to bear complex life was found to be approximately 2 orders of magnitude lower than the number predicted for primitive life forms, and the future missions DARWIN and TPF are likely to detect at least one planet with a biosphere composed of complex life.
We explore the minimum distance from a host star where an exoplanet could potentially be habitable in order not to discard close-in rocky exoplanets for follow-up observations. We find that the inner
A More Comprehensive Habitable Zone for Finding Life on Other Planets
The habitable zone (HZ) is the circular region around a star(s) where standing bodies of water could exist on the surface of a rocky planet. Space missions employ the HZ to select promising targets
Habitable zone lifetimes of exoplanets around main sequence stars.
The results show that exoplanet HD 85512b is no longer within the HZ, assuming it has an Earth analog atmosphere, and should be considered in future models of planetary habitability as setting an upper limit on the lifetime of any potential exoplanetary biosphere.
The Habitable Zone of Earth-like Planets with Different Levels of Atmospheric Pressure
As a contribution to the study of the habitability of extrasolar planets, we implemented a one-dimensional energy balance model (EBM), the simplest seasonal model of planetary climate, with new