It's called Kepler 22-b, it has a temperature of 22 degrees C, and it's only 600 light years away. It is the most Earth-like planet yet discovered by NASA, who have found hundreds of planets outside our own Solar System in recent years.
It is likely to be many years before any probes are sent to Kepler 22-b, but one vocal Green Rights groups called "Kill the Polar Bears" have said that the first probe sent to the planet should contain a nuclear bomb to destroy it.
Spokesman Harry Twatt said, "The human race has already destroyed the Earth. We mustn't be allowed to ruin this new world either. I mean, just look at what we've done to our planet. There isn't a single life form left on it, or one scrap of land still habitable. Clearly we can't be trusted with another planet and we should just go back to living in caves."
The "Kill the Polar Bears" group came to prominence a few years ago when they campaigned for all remaining polar bears in the Arctic to be shot, on the grounds that their natural habitat had already been ruined and they no longer had the same quality of life.
Extremist Green anti-human groups have been growing recently. It is thought it will only be a matter of time before the Greens begin campaigning for death camps for anyone whose lifestyle is deemed "not pure enough".