hunting habitable planets outside the solar system continues. The good old Hubble telescope has detected traces of water vapor in the atmosphere five exoplanets, a ‘signature’ crucial to hope to find a way of life as we know it on Earth. The study, conducted by a team of NASA, presented this week in the Astrophysical Journal .
five planets are “hot Jupiter” soft giants that circle their stars in a few days. Clearly, the conditions of temperature and pressure are extreme, and the water can not exist in liquid form. Impossible, therefore, to go for a swim.Other candidates
These planets are located more than 800 light years from Earth. They are too far away to send a probe for direct observation. However, there are better candidates.
For now, the most promising planets are about 20 light-years away. Gliese 581c and 667C are “Super Earths”, slightly larger than our planet, but a priori rocky and located in the habitable zone of their star. So far, nothing is known about their atmosphere and therefore it is unclear whether they contain water. To learn more, it will take the orbiting James Webb Space Telescope for direct observation, hopefully in 2018.