This “super-Earth” outside our solar system might have the right atmosphere and temperature to have liquid water.
“This is the first time that we have discovered an atmosphere around a planet that is not a gas giant—a super-Earth,” University College London (UCL) researcher Angelos Tsiaras explained. “And it is within a habitable zone of a star. This means that it has the right temperature to host liquid water.”
Astronomers from UCL says they found the molecule signature of water vapor on K2-18b, an exoplanet 110 light-years away. If their research, published on September 11, 2019, is confirmed, K2-18b could be the only exoplanet to have both water in its atmosphere and temperatures that would allow liquid water on a rocky surface.
K2-18b is classified as a super-Earth, one of hundreds of exoplanets with a mass between those of Earth and Neptune. But the name doesn’t mean it is habitable for life as we know it.
“It’s not Earth-like, necessarily,” UCL lecturer Ingo Waldmann explained. “It’s a heavier planet and it has a hydrogen-dominated atmosphere, so it might be habitable, but we don’t know that quite yet.”
Astronomers used data for NASA’s Hubble Space Telescope to analyze how K2-18’s light filters through K2-18b’s atmosphere.