A big part of water on Earth come from comets at the very early ages of Earth so I suppose that the comets has same age as the Earth. The Earth and other objects come from a waste after creation of the Sun. The Sun come from cloud of hydrogen and helium mostly. It is star of 3rd-generation so I suppose some other elements were present. If you disagree with anything let me know. I have two questions: 1) Why does the comets have more water than Earth? I mean percentually. 2) Where did the water that forms the comets come from?