Water detected in atmosphere of potentially habitable super-Earth

For the first time, astronomers have peered into the atmosphere of an exoplanet -- a planet outside our solar system -- and discovered both water vapor and temperatures that could potentially support life, according to a new study.

The exoplanet, known as K2-18b, is eight times the mass of Earth and known as a super-Earth, or exoplanets between the mass of Earth and Neptune. It orbits a red dwarf star 110 light-years away from Earth in the Leo constellation. The planet was first discovered in 2015 by NASA's Kepler spacecraft, CNN reports.

For the first time, astronomers have peered into the atmosphere of an exoplanet -- a planet outside our solar system -- and discovered both water vapor and temperatures that could potentially support life, according to a new study.

The exoplanet, known as K2-18b, is eight times the mass of Earth and known as a super-Earth, or exoplanets between the mass of Earth and Neptune. It orbits a red dwarf star 110 light-years away from Earth in the Leo constellation. The planet was first discovered in 2015 by NASA's Kepler spacecraft.

The researchers published their findings in the journal Nature Astronomy on Wednesday.

"Finding water in a potentially habitable world other than Earth is incredibly exciting," said Angelos Tsiaras, study author and research associate at the University College London's Centre for Space Exochemistry Data. "K2-18b is not 'Earth 2.0' as it is significantly heavier and has a different atmospheric composition. However, it brings us closer to answering the fundamental question: Is the Earth unique?"

The exoplanet completes one orbit around its star every 33 days and it's much closer to its star than Earth is to the sun. But the red dwarf star is also much cooler than our sun. Based on the researchers' calculations, they believe the planet could even be at a similar temperature to that of Earth. But the range extends to include temperatures much colder or warmer than Earth because of the constraints of their data.

The red dwarf star is an active one, however, which is likely exposing the exoplanet to more radiation than Earth receives.

"With so many new super-Earths expected to be found over the next couple of decades, it is likely that this is the first discovery of many potentially habitable planets," said Ingo Waldmann, study co-author and lecturer in extrasolar planets at the University College London's Centre for Space Exochemistry Data. "This is not only because super-Earths like K2-18b are the most common planets in our Galaxy, but also because red dwarfs - stars smaller than our Sun - are the most common stars."