“Resources exist to be consumed. And consumed they will be, if not by this generation then by some future. By what right does this forgotten future seek to deny us our birthright?” -Sid Meier’s Alpha Centauri
The dream of humanity has long been to identify an inhabited world beyond Earth, to know for certain that life is not unique to our pale blue dot. If we were located a great distance away, there are observations of Earth we could make that would tell us a tremendous amount of information about our world, including about its oceans, clouds, continents, the “greening” of our world during summer, the growth and shrinkage of icecaps and even atmospheric signatures.
The two sun-like stars, Alpha Centauri A and B, are located just 4.37 light years away from us and orbit one another at between the distances of Saturn and Neptune in our own solar system. Each may house Earth-like planets. Image credit: ESA/Hubble and NASA.
So why not apply that same line of thinking to search for Earth-like worlds around other sun-like stars? While direct imaging missions that would survey large numbers of stars would be very large and very expensive, the closest two sunlike ...