  The MIGHTEE large survey project will survey four of the most well-studied
extragalactic deep fields, totalling 20 square degrees to $\mu$Jy sensitivity
at Giga-Hertz frequencies, as well as an ultra-deep image of a single ~1 square
degree MeerKAT pointing. The observations will provide radio continuum,
spectral line and polarisation information. As such, MIGHTEE, along with the
excellent multi-wavelength data already available in these deep fields, will
allow a range of science to be achieved. Specifically, MIGHTEE is designed to
significantly enhance our understanding of, (i) the evolution of AGN and
star-formation activity over cosmic time, as a function of stellar mass and
environment, free of dust obscuration; (ii) the evolution of neutral hydrogen
in the Universe and how this neutral gas eventually turns into stars after
moving through the molecular phase, and how efficiently this can fuel AGN
activity; (iii) the properties of cosmic magnetic fields and how they evolve in
clusters, filaments and galaxies. MIGHTEE will reach similar depth to the
planned SKA all-sky survey, and thus will provide a pilot to the cosmology
experiments that will be carried out by the SKA over a much larger survey
volume.
