Methodology
All data comes from the exoplanet catalog of the Planetary Habitability Laboratory (PHL), retrieved on the 10th of October, 2018. Some data in this dataset are estimations calculated by the PHL, based on recorded data. For instance, the mass of many planets discovered by Kepler is defined by comparisons with mass classes of other exoplanets. The inner and outer edges of the Circumstellar Habitable Zones are also estimations.
The search for habitability by humans on an exoplanet is founded on Earth-like parameters (atmosphere, temperature, surface liquid water, etc.). Of course, this does not exclude the possibility of non Earth-like forms of life.
Many thanks to Dr. Caroline Dorn for helping us understand the stakes of exoplanetary science. Dr. Dorn is a geophysicist at the Institute for Computational Sciences, University of Zurich. Her research focuses on the interior of exoplanets.
Conception and realization
Luc Guillemot
Nadine Prigann
Solange Vogt
and everybody at Interactive Things
November 2018
Sources
Discovery methods
NASA Missions and projects
Exoplanets
Terminology