Alpha Centauri does have a planet
We've discovered a lot of exoplanets, including rocky Earth-like ones, in far-away star systems. But the European Space Agency announced this afternoon that our solar system's nearest neighbor, a brilliant trinary star system called Alpha Centauri, has a planet that's roughly the mass of Earth. That's right  just 4.3 light years away, there's a planet that might be a lot like our own.Might, but it's not, the year is 3 days long so it must be in an ultra tight orbit. That would make it a sun blasted Mercury rock ball.
It is more significant in that it is the first planet with a mass near that of the Earth. As detectors get more sensitive and methods get developed, scientists have been finding smaller and smaller planets. They have finally pushed it down to the range of Earth sized planets, at least for nearby systems with good viewing conditions.