Earth is the only body in the solar system with liquid water on its surface. But it’s not the only one where you can find water. In fact, water is everywhere – from comets and asteroids to the giant planets.

Comets and asteroids are chunks of rock, metal, and ices – including water ice. Comets have more ice, but most asteroids probably have large amounts as well. Such bodies might have supplied much of the water on Earth when they collided with our planet billions of years ago.

Water ice is common throughout the solar system. It’s been seen at the poles of the Moon and the planet Mercury – the Sun’s closest planet. It forms large polar caps on Mars. And it coats many of the moons of the giant outer planets.

Water also has been detected in the clouds of Jupiter and Saturn. And it may be a major component of the outer layers of Uranus and Neptune, the Sun’s most remote planets.

To find liquid water, you have to go deep. There may be global oceans of water far below the surfaces of some of the big moons of Jupiter and Saturn, and perhaps some moons of Uranus and Neptune as well. Some of those oceans could hold more water than all of Earth’s oceans combined.

On Earth, water is a key ingredient for life. So some of the moons of the outer planets are considered good places to look for life – swimming in oceans of liquid water.

We’ll talk about water beyond the solar system tomorrow.

Script by Damond Benningfield