Water detected in atmosphere of Earth-like planet for the first time

Scientists for the first time have detected water in the atmosphere of an Earth-like planet orbiting a distant star, evidence that a key ingredient for life exists beyond our solar system, according to a study published on Wednesday.

Water vapor was found in the atmosphere of K2-18b, one of hundreds of “super-Earths” - worlds ranging in size between Earth and Neptune - documented in a growing new field of astronomy devoted to the exploration of so-called exoplanets elsewhere in the Milky Way galaxy, Reuters reports.

The latest discovery was reported in research by a team of scientists at University College London (UCL) published in the peer-reviewed journal Nature Astronomy.

– We found water – UCL astrophysicist Ingo Waldmann told Reuters of the breakthrough, revealed from observations made with the Hubble Space Telescope, which analyzed starlight filtered through K2-18b’s atmosphere.

More precisely, it marks the first time scientists have found water in the atmosphere around a super-Earth - as opposed to a gas giant - orbiting a star within its “habitable zone,” just the right distance for liquid water to potentially exist on the surface.

Aside from the tremendous distance separating Earth from K2-18b, the exoplanet is likely exposed to far more radiation than Earth, diminishing the prospects for life evolving there.

However, the discovery brings astronomers closer to answering the fundamental question of how unique Earth is in the universe, the scientists said.

Ingo Waldmann

water on planets

water in space

habitable planets

K2 18b