How the rocks ended up there will be a 'mystery forever'.
Beyond Neptune, a smaller 'ninth' planet has been identified in the Kuiper Belt.
'Smartphones are part of life, they're everywhere and they're not going anywhere.'
Nasa will closely monitor the asteroid.
'It's very difficult for families to deal with these diseases, they are devastating, so to see babies born at the end of this is just amazing really.'
'It will soon be impossible to distinguish between real and manipulated material.'
A deep, long probe helped experts discover this.