ABSTRACT
This chapter entails the characterization of an exoplanet in terms of metric indices with values ranging from zero to ‘one’ to understand various aspects of its habitability; Earth Similarity Index to help identify how similar the planet is to our earth, Planetary Habitability Index for its ability to support life, Mars Similarity Index to detect if the planet is more like Mars in our solar system, Active Tardigrade Index to determine if tardigrades can survive on the planet, Cryptobiotic Tardigrade Index indicative of an organism’s response to environment, and Rock Similarity Index to determine suitability for rock-dependent microorganisms capable of living in extreme weather conditions. The chapter ends with a mathematical example of arriving at the above mentioned indices and includes some numericals for the readers to solve.
