NASA has announced that for the first time, Hubble Space Telescope has discovered an exoplanet with water vapor that exists within the habitable zone of its star. The exoplanet has been named K2-18b and it is located outside of our solar system. Because the planet’s atmosphere contains water vapor and it’s located within the habitable zone, there may be bodies of liquid water located on the surface.
The exoplanet K2-18b is what is known as a ‘super-Earth,’ meaning it is larger than our planet and, in this case, also has greater surface density. This is currently the only known exoplanet that contains water and also temperatures that are within the range necessary for supporting life, making it a key discovery for future potential missions.
The exoplanet is located around 110 light-years from its red dwarf star and though it is within the habitable zone with a favorable atmosphere, the space agency notes that it probably experiences far more high-energy radiation than our own planet, meaning it may ultimately be ‘hostile to life.’
The discovery of water vapor in the planet’s atmosphere was recently detailed in a study published in Nature Astronomy. NASA points out that K2-18b is one of hundreds of previously discovered super-Earth exoplanets; it was identified by the Kepler Space Telescope back in 2015 and later observed by the Hubble Space Telescope.
According to NASA, scientists used Hubble data on the exoplanet from 2016 and 2017 with open-source algorithms to study the super-Earth’s atmosphere. In addition to helium and hydrogen, it’s possible that K2-18b’s atmosphere also contains methane and nitrogen, among other molecules, though it will take additional research to determine that.