The search for worlds outside our solar system has come a long way since the first exoplanets were confirmed in the early 1990s. Since then, the average rate of alien-world discoveries has shot from about three per year to between fifty and a hundred per year in the last five years. As of the end of 2012, with the tally standing at 854 newfound worlds and reports of new detections being announced nearly every week, thanks in large measure to NASA’s Kepler space telescope, astronomers are calling this the golden age of exoplanet discovery.
Now the race is on to find Earth’s twin, the elusive Earth-size planet in the habitable, or “Goldilocks,” zone around a star where liquid water can exist—and experts believe we may hit the cosmic jackpot soon.
In 2012 astronomers came closer than ever to zeroing in on an earthly doppelganger, or at the very least a planet considered potentially habitable.
However, we are far from confirming the habitability of any of these planets until we have the capability to observe their atmosphere, but that will take many years. The big goal now is to find an Earth-size planet in its star’s habitable zone—something more similar to Earth.