from space, the most striking feature of our planet is the water. In both liquid and frozen form, it covers of the Earth’s surface. It fills the sky with clouds. Water is practically everywhere on Earth, from inside the rocky crust to inside our
is first planet confirmed "smack in the middle of the habitable zone." The habitable zone is the region around a star where a planet's surface is not too hot and not too cold for liquid water—and thus life as we know it—to exist.