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In Europe a network (EVN) has been organized linking 

 existing telescopes in The Netherlands, West Germany, Great 

 Britain, Italy and Sweden. A joint operation of the 

 American-Canadian and European arrays could produce a truly 

 giant instrument of remarkable image forming speed and fineness 

 of detail. 



The VLBA on the ground is a prelude to radio interferometry 

 in space that could begin sometime before the end of the century 

 with an orbiting dish (Quasat) linked to an international net on 

 the ground. It can be expected to improve the resolution to 

 about 60 microarc seconds. Where the natural limits on the 

 sizes of energetic sources in the galaxy will be found is not 

 yet known. With a resolution of a millionth of an arc second, 

 astronomers will be able to look at the sources of tightly 

 beamed relativistic jets of plasma, millions of light years long 

 generated in the immediate vicinity of what are believed to be 

 massive rotating black holes. We still do not understand the 

 generation, collimation and interaction of these jets with the 

 surrounding medium. And we cannot hope to understand such 

 remarkable phenomena any better without being able to probe with 

 very much higher resolution. 



The second step in the Quasat concept will project radio 

 telescopes into far more distant orbits and they will have to 

 work Interferometrically with each other as well as with the 



