The watery exoplanet K2-18 b is surrounded by water vapor in this artist’s illustration. (Credit: Alex Boersma)

Astronomers have finally uncovered water vapor in the atmosphere
of a super-Earth exoplanet orbiting within the habitable zone of its star. The
find means that liquid water could also exist on the rocky world’s surface,
potentially even forming a global
ocean.

The discovery, made with NASA’s Hubble Space Telescope, serves as the
first detection of water vapor in the atmosphere