Free Astronomy Magazine November-December 2019

NOVEMBER-DECEMBER 2019 T wo of the main protag- onists in the twenty years- long history of exoplanets: the Kepler Space Tel- escope, the most prolific discov- erer, and the HARPS spectro- graph, the most precise validator. Together they have revolution- ized extrasolar planetology. [NASA, ESO] that goes through their atmospheres before reaching the observer. Not enough signal comes from Earth-like planetary atmos- pheres for astronomers to be able to distin- guish signal from noise. It is, therefore, useless to look at these planets for the “house keys” (that is, a livable world). Not being able to do otherwise for the time being, astronomers are accordingly looking for the “keys” where there is more light. Even if they do not find Earth-like environ- ments, they improve their skills as seekers, waiting for the “park” to become less dark. The best, technically-achievable result today is the discovery of water in the atmosphere of a super-Earth orbiting inside the habitable zone of a red dwarf. This very result was re- cently reported by two teams of researchers, leading to a kind of mass media sensational- ism not entirely appropriate or warranted.