CUBES, the Cassegrain U-Band Efficient Spectrograph, aims to bring a unique capability to ESO's Very Large Telescope: an ultraviolet eye on the Universe to complement the Extremely Large Telescope, a super-efficient (> 40%) spectrograph with a spectral coverage of 300–405 nm in the present design and two resolution modes, 20000 and 7000. An option of a fibre link to the Ultraviolet and Visual Echelle Spectrograph is foreseen that will provide the capability of simultaneous optical high-resolution spectroscopy at λ > 420 nm. The CUBES design is able to address a treasure trove of scientific cases, from Solar System science to cosmology.
