Solar prominences are one of the clearest examples of a multiphase solar atmosphere: cool, dense plasma embedded within the hot corona and maintained over extended timescales. Recent work has pushed the field beyond largely descriptive studies towards a more quantitative understanding of how such structures form, evolve, and are observed.

Prominences are increasingly treated as part of a broader class of condensation phenomena in the corona, closely linked to thermal instability, heating localisation, and radiative losses. At the same time, it has become clear that no single formation mechanism is sufficient: injection, levitation, and evaporation–condensation processes likely operate together, with prominence mass maintained through a continuous and evolving balance rather than a single event.

Observational advances reinforce this picture. High-resolution, multi-instrument data show prominences to be highly structured and dynamic on fine spatial scales, with flows, oscillations, and instability signatures occurring at thread-like dimensions. This exposes the limitations of simplified geometries and optically thin assumptions. In particular, recent radiative-transfer work demonstrates that non-local thermodynamic equilibrium effects and geometry are central to interpreting diagnostics, placing forward modelling at the core of model–data comparison.
This colloquium will present a synthesis of these developments. The emerging view is that prominences are best understood as long-lived, magnetically structured condensations within a multiphase corona, whose interpretation depends on combining self-consistent MHD modelling with NLTE radiative diagnostics. Key open problems remain, including constraining magnetic structure observationally, identifying dominant plasma supply pathways across different prominence classes, and achieving consistent agreement between models and multiwavelength observations.