https://en.wikipedia.org/wiki/Absorption_spectroscopy https://en.wikipedia.org/wiki/Absorption_spectroscopy We can detect water, and oxygen in the atmosphere u

https://en.wikipedia.org/wiki/Absorption_spectroscopy https://en.wikipedia.org/wiki/Absorption_spectroscopy We can detect water, and oxygen in the atmosphere using this method. Plus we can estimate it's temperature based on it's orbit and star's energy. If it is in the habitable zone we can only suspect that it potentially can support life, but we cannot detect if life exists there. Well, even if we could do that we would get data from N years from the past, depending on the distance.