A planet’s habitability, or ability to harbor life, results from a complex network of interactions between the planet itself, the system it’s a part of, and the star it orbits. The standard definition for a habitable planet is one that can sustain life for a significant period of time. As far as researchers know, this requires a planet to have liquid water. To detect this water from space, it must be on the planet’s surface. The region around a star where liquid surface water can exist on a planet’s surface is called the “habitable zone.” However, this definition is confined to our understanding of current and past life on Earth and the environments present on other planets. As researchers learn more and discover new environments in which life can sustain itself, the requirements for life on other planets may be redefined.
Different types of planets may drive processes that help or hinder habitability in different ways. For example, planets orbiting low-mass stars in the habitable zone may be tidally locked, with only one hemisphere facing the star at all times. Some planets may be limited to only periodic or local habitable regions on the surface if, e.g., they experience periodic global glaciations or are mostly desiccated. In order to understand the full range of planetary environments that could support life and generate detectable biosignatures, we require more detailed and complete models of diverse planetary conditions. In particular, understanding the processes that can maintain or lead to the loss of habitability on a planet requires the use of multiple coupled models that can examine these processes in detail, especially at the boundaries where these processes intersect each other.
Vladimir Airapetian, Giada Arney, Tony Del Genio, Shawn Domagal-Goldman, Thomas Fauchez, Alex Glocer, Scott Guzewich, Nancy Kiang, Ravi Kopparapu, Weijia Kuang, Avi Mandell, Luke Oman, Jeremy Schnittman, Linda Sohl, Kostas Tsigaridis, Michael Way
Key Questions Guiding SEEC Research
By studying ways that biospheres interact with planetary environments, SEEC researchers are pioneering methods to detect life on other worlds.
A vast multitude of physical, chemical, and geological processes combine to produce the characteristics of a specific exoplanet’s atmosphere and surface that will be visible to future telescopes.
Planetary habitability results from a complex network of interactions between the planet, its planetary system, and host star.
In our quest to find life outside of our solar system, we look for planets that resemble Earth, the only planet that we know of that is habitable.
Earth is our only example of a planet that is habitable and inhabited, and as such represents the archetypical habitable environment for remote sensing and mission development studies.