Is Proxima Centauri b, the closest exoplanet, a habitable world
or otherwise similar to Earth? I wrote an article about it at the
official blog of the discovery, Pale Red Dot.
It's based on the scientific article The Habitability of Proxima Centauri b I: Evolutionary Scenarios,
submitted to the journal Astrobiology. We conclude that the
nearly 200 million years the star spent interior to the
habitable zone (where Earth-like conditions are most likely) is the
biggest difference between the Earth's and Proxima b's evolution.