For many years, planetary scientists have believed that water-rich meteorites arriving late in Earth's history (OK, the time ...

It was long thought, up until recently, that asteroids and comets delivered Earth's oceans during the early Solar System.

For the Moon itself, the story is different. The Moon has far less water than Earth, but for such a dry world it’s important. Most of it lies frozen in dark polar craters, and these icy spots could ...