spacetoday.net: Astronomers find water in atmosphere of exoplanet

Astronomers find water in atmosphere of exoplanet

Posted: Sun, Sep 15, 2019, 8:01 AM ET (1201 GMT)
K2-18b exoplanet illustration (NASA/GSFC)

Astronomers have found a planet in a star's habitable zone with evidence of water in its atmosphere, but don't make your travel plans there just yet. The planet, K2-18b, orbits its star at a distance where liquid water could exist, and spectral data from the Hubble Space Telescope showed evidence of water vapor. While some scientists called the exoplanet "the best candidate for habitability that we know right now," others cautioned the planet, about eight times the mass of the Earth, is more like a "mini-Neptune" versus a super-Earth with a dense hydrogen atmosphere that could form a layer of liquid hydrogen.