Researchers at the University of Puerto Rico are keeping a list.
According to the Exoplanet Catalog maintained by the Planetary Habitability Laboratory (PHL) of the University of Puerto Rico at Arecibo, the number of confirmed planets outside our own solar system is approaching 1,000, while another 3,500 exoplanets—most of them detected by NASA’s Kepler mission—are yet to be confirmed. We’re not talking only about Jupiter- or Neptune-like gas giants, but also Super-Earths (terrestrial planets several times the mass of Earth) and Earth-size planets.
Source: PHL at UPR Arecibo
From this growing list, the PHL, directed by Abel Méndez, has identified the top 12 potentially habitable exoplanets based on an Earth Similarity Index (ESI). Their top choice is Kepler 62e, with an ESI value of 0.83 (an ESI of 1.0 would be a 100 % match with Earth in terms of astronomical parameters). Kepler 62e is a Super-Earth in the Constellation Lyra, with an estimated mass of 3.6 Earth masses and an estimated radius 1.6 times that of Earth. Its surface temperature is estimated at 31oC (88oF) and it is 7 billion years old, significantly older than Earth. It’s also very far away—1,200 light years, meaning that we won’t be visiting ...