The search for extraterrestrial life goes on, sort of. We do it, as half-heartedly as we do anything in space, because we're more afraid of being alone than finding another civilization. Or vice versa.
But we may not be looking in the best spots, even if we are looking in the Habitable Zones. Looking for planets or moons outside the "stellar habitable zone" might lead to environments that are even more favorable to supporting life than here on Earth, according to a crazy/insightful article in Astrobiology. These superhabitable worlds might have unique characteristics and be ideal targets for extrasolar exploration, the authors speculate, though that won't mobilize a lot of policymakers.
Such worlds would likely be older than Earth, and larger than Earth, and be orbiting K Dwarf stars, around 0.6 to 0.9 the mass of our sun. Alpha Centauri B is one such K-type main sequence star, and really close, relatively speaking.
René Heller of McMaster University and John Armstrong of Weber State University also propose that tidal heating can create conditions in which life could emerge on an icy or terrestrial planet or moon once thought to be uninhabitable.
Habitable orbits for an Earth-like exomoon around a Jupiter-like planet around a solar-luminosity star. Green areas illustrate orbits, in which the total energy flux of absorbed illumination and tidal heating is above the maximum greenhouse limit Seff,MaxGr and below the moist greenhouse threshold Seff,MoiGr. Within these stripes, orbits with tidal heating rates above 100 W/m2 are highlighted in orange. The circumplanetary habitable edge, here defined by the moist greenhouse, is indicated with a red line. doi:10.1089/ast.2013.1088
Does Alpha Centuari B host such a planet? It's supposed to, that's been believed for a long time. If you played the original Civilization computer game in 1991, you could go to Alpha Centauri at the end, and Isaac Asimov took us there in 1940 when he wrote "Homo Sol."
To find out, we just have to be biocentric rather than geocentric or anthropocentric, they write.
We shouldn't be blinded by "mediocracy", the belief that a random choice that is picked must come from the numerous choices available, which would lead us to believe life like us must come from a planet like ours, according to the authors.
Citation: René Heller and John Armstrong, 'Superhabitable Worlds', Astrobiology, January 2014, 14(1): 50-66 doi:10.1089/ast.2013.1088.