  SPHERE (Beuzit et al,. 2019) has now been in operation at the VLT for more
than 5 years, demonstrating a high level of performance. SPHERE has produced
outstanding results using a variety of operating modes, primarily in the field
of direct imaging of exoplanetary systems, focusing on exoplanets as point
sources and circumstellar disks as extended objects. The achievements obtained
thus far with SPHERE (~200 refereed publications) in different areas
(exoplanets, disks, solar system, stellar physics...) have motivated a large
consortium to propose an even more ambitious set of science cases, and its
corresponding technical implementation in the form of an upgrade. The SPHERE+
project capitalizes on the expertise and lessons learned from SPHERE to push
high contrast imaging performance to its limits on the VLT 8m-telescope. The
scientific program of SPHERE+ described in this document will open a new and
compelling scientific window for the upcoming decade in strong synergy with
ground-based facilities (VLT/I, ELT, ALMA, and SKA) and space missions (Gaia,
JWST, PLATO and WFIRST). While SPHERE has sampled the outer parts of planetary
systems beyond a few tens of AU, SPHERE+ will dig into the inner regions around
stars to reveal and characterize by mean of spectroscopy the giant planet
population down to the snow line. Building on SPHERE's scientific heritage and
resounding success, SPHERE+ will be a dedicated survey instrument which will
strengthen the leadership of ESO and the European community in the very
competitive field of direct imaging of exoplanetary systems. With enhanced
capabilities, it will enable an even broader diversity of science cases
including the study of the solar system, the birth and death of stars and the
exploration of the inner regions of active galactic nuclei.
