Scientists develop new method to find water on other planets

Earth is known as the Blue Planet because it has so much water on its surface

Life on Earth depends on water to survive - which is why scientists look for signs of water when searching for life on other planets.

These planets are sometimes known as "water worlds".

Scientists looking through the galaxy for signs of life have found there could be more water worlds than they thought!

They hope they can find planets similar to Earth.

It's estimated there are around 100 thousand stars in the Milky Way alone

Because the planets they are looking at are so far away, it's hard to see exactly what they look like - so they can't assume planets will be like Earth, with water on the surface.

The scientists say it's likely that some of these planets actually have water trapped inside rock.

Researchers use special methods to work out how big a planet is, and what it could be made of.

This can be worked out by studying the way the planets move around their nearby star.

Scientists look at the gravitational pull a planet has on a star - which tells them how large and dense the planet might be.

The more mass it has, the more it pulls on the star.

Water is less dense than rock, and so when a planet has less gravitational pull on a star than its mass and size would suggest, it could mean the planet has water inside of it.

Scientists involved in the project looked at a group of planets around an M-dwarf star - which is the most common type of star in the galaxy.

Rafael Luque, who is a researcher in water worlds at the University of Chicago, said the discovery has "enormous consequences for the search for habitable planets."