Obliquity Variability of a Potentially Habitable Early Venus

Abstract

Venus currently rotates slowly, with its spin controlled by solid-body and atmospheric thermal tides. However, conditions may have been far different 4 billion years ago, when the Sun was fainter and most of the carbon within Venus could have been in solid form, implying a low-mass atmosphere. We investigate how the obliquity would have varied for a hypothetical rapidly rotating Early Venus. The obliquity variation structure of an ensemble of hypothetical Early Venuses is simpler than that Earth would have if it lacked its large Moon (Lissauer et al., 2012), having just one primary chaotic regime at high prograde obliquities. We note an unexpected long-term variability of up to $\pm 7^{\circ }$ for retrograde Venuses. Low-obliquity Venuses show very low total obliquity variability over billion-year timescales -- comparable to that of the real Moon-influenced Earth.

in revision at _Astrobiology_

References in corpus (7)

• Dynamics of the giant planets of the solar system in the gaseous proto-planetary disk and relationship to the current orbital architecture
• Effects of Extreme Obliquity Variations on the Habitability of Exoplanets
• Obliquity evolution of extrasolar terrestrial planets
• On the Spin-axis Dynamics of a Moonless Earth
• A dynamical study on the habitability of terrestrial exoplanets II: The super Earth HD 40307 g
• Impact-driven planetary desiccation: The origin of the dry Venus
• Pre-LHB Evolution of the Earth's Obliquity

Cited by in corpus (10)

• Was Venus the First Habitable World of our Solar System?
• Venusian Habitable Climate Scenarios: Modeling Venus through time and applications to slowly rotating Venus-Like Exoplanets
• Obliquity and Eccentricity Constraints For Terrestrial Exoplanets
• The Fundamental Connections Between the Solar System and Exoplanetary Science
• Obliquity Variations of Habitable Zone Planets Kepler-62f and Kepler-186f
• Obliquity Evolution of the Potentially Habitable Exoplanet Kepler-62f
• Gravity-Darkened Seasons: Insolation Around Rapid Rotators
• Obliquity Evolution of Circumstellar Planets in Sun-like Stellar Binaries
• Effects of the general relativistic spin precessions on the habitability of rogue planets orbiting supermassive black holes
• Plausibility of Capture into High-Obliquity States for Exoplanets in the M Dwarf Habitable Zone