Simulations of observations of an aerosol-free HD189733b with HARPS-N (upper left panel), ESPRESSO (upper right panel) and GIANO (lower left panel). The number of observed transits ranges from 1 (light green) to 9 (purple). A red solid line indincates a noise-free transmission spectrum. While the signal is buried in the photon noise, the combination of 800 water lines results in a detection in the ,, Y, J, and H bands. In the , and bands, water absorbs all the incident light making detection impossible from the ground.