Why not us interferometry to take a picture of Pluto?
Radio interferometry can combine observations over very large baselines.  But optical interferometry cannot.  According to a list of interferometry instruments on wikipedia, the largest baseline for optical measurements is less than a kilometer.  We can't take optical measurements with continent-sized instruments.

Then if you drop down to radio where the instruments do have that capability, I think you'll find Pluto is quite dim (it's not a radio source, and there's no strong radio emissions that it can reflect to us). There's no radio signal from Pluto that can be imaged.

From a page on optical interferometry:


  Interferometers are seen by most astronomers as very specialized
  instruments, as they are capable of a very limited range of
  observations. It is often said that an interferometer achieves the
  effect of a telescope the size of the distance between the apertures;
  this is only true in the limited sense of angular resolution. The
  combined effects of limited aperture area and atmospheric turbulence
  generally limit interferometers to observations of comparatively
  bright stars and active galactic nuclei.