Water Vapor Discovered on Distant Exoplanet.

Where else might life exist? One of humanity's great outstanding questions, locating planets where extrasolar life might survive took a step forward recently with the discovery of a significant amount of water vapor in the atmosphere of distant exoplanet K2-18b . The planet and it parent star, K2-18 , lie about 124 light years away toward the constellation of the Lion ( Leo ). The exoplanet is significantly larger and more massive than our Earth, but orbits in the habitable zone of its home star. K2-18, although more red than our Sun, shines in K2-18b 's sky with a brightness similar to the Sun in Earth's sky . The discovery was made in data from three space telescopes: Hubble , Spitzer , and Kepler , by noting the absorption of water-vapor colors when the planet moved in front of the star. The featured illustration imagines exoplanet K2-18b on the right, its parent red dwarf star K2-18 on the left, and an unconfirmed sister planet between them.