Old and New aspects of the prominence physics from coronal observations

Classical W-L eclipse observations showed dark cavities surrounding prominences. Using colour index analysis and/or higher spatial resolution observations small dynamical cool clouds are seen moving inside the inner corona around prominences.
More recent EIT (SoHO) observations taken using the 304 A channel showed He+ prominences not seen in cooler lines. TRACE movies of the Fe IX and XI emissions also brought a lot regarding the dynamical surrounding of prominences.
We re-examine the significance of the cavity type coronal structures with a possible interpretation as magnetic interlaced 3-D flux ropes evacuating the corona. Future space missions should pay more attention to the diagnostics of cavities and emptiness, taking into account the coronal dynamics around prominences, in order to resolve the long standing problem of the origin of prominences.