SPACE — Scientists have found water for the first time on a potentially habitable exoplanet.

According to the Washington Post, exoplanet K2-18b is twice as big as Earth, with eight times its mass. It orbits a red dwarf star 110 light years or 650 million miles away from Earth, completing an orbit every 33 days.

K2-18b sits in its star's habitable zone. The BBC reports that this gives it a temperature of between zero and 40 degrees Celsius, cool enough to have liquid water.

Using data collected by the hubble space telescope, scientists studied looked for subtle changes in starlight as it filtered through K2-18b's atmosphere.

According to CNN, they detected the molecular signature for water vapor in the planet's atmosphere, along with the signatures for hydrogen and helium.

The BBC reports that computer modelling of the data suggests as much as 50 percent of the planet's atmosphere could be composed of water.

According to CNN, researchers say other elements like nitrogen or hydrogen could be present in the planet's atmosphere, but can only be revealed by more advanced future telescopes such as the James Webb Space Telescope or ESA's Ariel mission.