This is the original page just before the launch of the catalog on December 5, 2011. It is kept here for historical reasons. The catalog is available now here.
The Habitable Exoplanet Catalog (HEC) is a new project by the PHL to help identify, organize, and visualize habitable exoplanets discoveries. The HEC is still under construction and will be available here on December 5, 2011. This is the second major project of the PHL after the Visible Paleo-Earth. Send an email to Prof. Abel Méndez to be included in the project mailing list.
There are various catalogs for the near 700 exoplanets that have been confirmed, the Extrasolar Planets Encyclopaedia, the Exoplanet Data Explorer, and The Visual Exoplanet Catalogue among the best. After over fifteen years of observations, scientists are now starting to identify potential habitable exoplanets, like Gliese 581d.
New observations with ground and orbital observatories, like Kepler, will help to identify tens or even hundreds of new potential habitable exoplanets in the coming years. The HEC will use new developments by the PHL like the Earth Similarity Index (ESI), the Habitable Zones Distance (HZD), classification systems, and comparisons with Earth past and present, to help assess the habitability of these discoveries.
Here is an example of the HEC for Solar System planets as context. Three complementary habitability metrics are shown. The HZD is a measure of how far is the planet from the center of the habitable zone, zero being exactly in the center. The ESI compares the similarity of various planetary properties with Earth, a value of one being identical to Earth. The SPH is a measure of how good is the surface to support life, with a value of one being optimum. Check here the full explanation.