Breaking Old Habits: New Models for Habitability Beyond Earth

Post date: Aug 11, 2021 7:51:44 PM

A collaboration of international scientists is leading the development of habitability models in the astrobiology field. The Planet-Hab Collaboration, led by the Planetary Habitability Laboratory of the University of Puerto Rico at Arecibo, would be adapting the decades-long experience of terrestrial habitability modeling to other environments in the universe, from Earth to exoplanets.

Astrobiologists have been proposing different and conflicting ways to define and measure habitability since the early 2000s, a situation not much different from what ecologists experienced and solved in the early 1980s. Many of the ideas behind habitat suitability models in ecology can be adapted to the current needs of the astrobiology community.

The paper published in Astrobiology urges the scientific community to adopt and expand the models used by ecologists. Most habitability assessments are based on identifying the presence of environmental factors that are necessary for life. The models used in ecology go beyond these assessments to also characterize the net effect of each component individually or in combination.

Astrobiologists and ecologists have historically worked independently on habitability models for different reasons. Ecologists want to understand and predict the distribution of terrestrial life, and astrobiologists are searching for habitable environments beyond Earth. The difference in nomenclatures and applications caused a decades-long disconnection between the two fields.

Observations from current and future planetary missions could be used to construct standardized habitability models that would help quantify and compare the suitability for life of different planetary environments, including terrestrial and planetary environments. The models can be fine-tuned to be less or more centric to terrestrial life.

Applications are not limited to terrestrial environments or the Solar System. We do not have enough information about exoplanets today to evaluate their specific habitability. However, computer models are being used to study their potential global climate scenarios. These models do include enough information for them to be compared with habitability models.

Habitability models can be used to characterize the spatial and temporal distribution of habitable environments, identify any regions of interest in the search for life, explore the correlations between habitability and biosignatures and help understand the diversity of potential habitats of early life on earth. For example, all habitable environments by terrestrial standards are inhabited, but we do not know if this is true elsewhere in the universe.

The Planet-Hab Collaboration consists of a large multidisciplinary group of scientists from over twenty international institutions, including NASA. The collaboration is now constructing and applying the new habitability models to Martian environments, the clouds of Venus, the oceans of Europa, other Solar System bodies of interest, and exoplanets.

Media Contacts

    Prof. Abel Méndez, PHL @ UPR Arecibo:

    Dr. Edgard G. Rivera-Valentín, LPI/USRA,

    Dr. Dirk Schulze-Makuch, Technische Universität Berlin,

Associate Publication: Méndez, A., Rivera-Valentín, E. G., Schulze-Makuch, D., Filiberto, J., Ramírez, R. M., Wood, T. E., Dávila, A., McKay, C., Ortiz Ceballos, K. N., Jusino-Maldonado, M., Torres-Santiago, N. J., Nery, G., Heller, R., Byrne, P. K., Malaska, M. J., Nathan, E., Simões, M. F., Antunes, A., Martínez-Frías, J., Carone, L., Izenberg, N. R., Atri, D., Carvajal Chitty, H. I., Nowajewski-Barra, P., Rivera-Hernández, F., Brown, C., Lynch, K., Catling, D., Zuluaga, J. I., Salazar, J. F., Chen, H., González, G., Kashyap Jagadeesh, M., Haqq-Misra, J. (2021). Habitability Models for Astrobiology. Astrobiology, 21(8), 1017-1027.

DOI: 10.1089/ast.2020.2342 (