Scientists discover super earth with water

Scientists have for the first time found a planet outside of our solar system that's home to water, in a major breakthrough in the search for habitable worlds.

Water vapour has been discovered on a 'super-Earth' 110 light years away that is estimated to be twice the size of Earth and eight times its mass.

K2-18b also has an atmosphere and the correct temperature range for living things to exist, according to scientists at University College London.

It's closer to its star than the Earth is to the Sun, meaning it has shorter years, and completing its orbit in 33 days while ours takes 365. 

The exoplanet was first spotted in 2015 by NASA's Kepler spacecraft but analysis of data has revealed new details not seen before.

Current equipment is only able to determine basic factors such as how far away it is, its mass and the surface temperature.

But sophisticated tools developed at UCL have been able to translate data from the Hubble Space Telescope to make sense of the unique molecule signatures of water vapour.

K2-18b is too far away for astronomers to see, but they can look at how starlight is filtered through the planet's atmosphere as it passes around its own sun, called K2-18.

It's the only planet outside our solar system that we know has the correct temperature, an atmosphere and water,' said Dr Angelos Tsiaras the author of the study.

The presence of water vapour in the planet's atmosphere suggests it could be a rocky world or an icy one with a lot of water inside it.

Most other exoplanets like this have been gas giants, such as Jupiter and Saturn, so K2-18b offers a valuable opportunity for researchers to study smaller, rocky or icy planets.