Doctor: Further than we've ever gone before...
New Earth exists in the year 5 billion 23, in the galaxy M87. There is apple grass there. The Doctor explains that in the year 5 billion, the sun explodes and the original Earth roasts. Humans, of course don't die out, as they've moved out all over the universe (if we could just get on with that please!) and there was a sort of nostalgic movement. So they found a planet that was the same size as the earth, has the same air and the same orbit and they turned it into New Earth.
The even built New New York. "Strictly speaking its the 15th New York as the original - that would be New New New New New New New New New New New New New New New York..."
It's brilliant, just brilliant. To think that out there in this giant never-ending universe there might just be another planet that is so like ours, that we can actually name it New Earth without looking utterly ridiculous. But then I wonder - if it's just like Earth, did we have to fight the people living on it to make it ours? Did we buy it? Did we simply invade, take over, and that was that. Or was it empty? Did we get overwhelmingly lucky and just happen to move into a completely empty planet (of intelligent life, that is)...
Well, maybe one day, I'll get to stand on apple grass and stare at a completely foreign, yet completely familiar sky.
In conclusion, go watch Doctor Who, new season 2, episode 2. If you do, you'll also get to see the cat people!