Super-Earth exoplanet K2-18b, illustration. Also known as EPIC 201912552 b, this planet orbits the red dwarf K2-18 which is 124 light years from Earth, in the constellation of Leo. The planet is eight times the mass of Earth, and takes 33 days to orbit its parent star at an average distance of 21.3 million kilometres. It is within the habitable zone of the star, and in 2019 scientists announced the discovery of water vapour in its atmosphere. They had analysed the starlight filtered through the planet's atmosphere. The results revealed the molecular signature of water vapour, also indicating the presence of hydrogen and helium.