568 Michael Sterzik Deciphering dayglow as biosignature of planet Earth Biosignatures in the near-infrared of Earths atmosphere include the simultaneous presence of H2O, O2 and CH4 molecular absorption bands, but also include abundant skyline emission features (e.g. OH), caused by chemo-photolytic reaction networks of oxygen in the upper atmosphere. Here we present new infrared spectra of earthshine obtained with the CRIRES+ instrument at the VLT. The high spectral resolution of CRIRES+ allows us to discern Earth's reflection spectrum from the contaminating atmospheric transmission. Our earthshine spectra show strong features of dayglow emission, and allow to assess its strength by comparing earthshine to signal levels of background nightglow. Our CRIRES+ observations of earthshine open a novel window for the detection of biosignatures of Earth-like planets.