A Maximum Radius for Habitable Planets
Abstract
We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.
- Publication:
-
Origins of Life and Evolution of the Biosphere
- Pub Date:
- September 2015
- DOI:
- 10.1007/s11084-015-9440-7
- Bibcode:
- 2015OLEB...45..319A
- Keywords:
-
- Planet structure;
- Habitability;
- Planet composition