Very Long Baseline Interferometry - the sharpest views of the invisible
Around the planet, astronomers have huge parabolic dishes and large arrays of antennas turned towards the skies. These radio telescopes extend the observable electromagnetic spectrum by many orders of magnitude.
Radio telescopes must be very large in size to achieve the same resolution as optical telescopes. The only way to do this is by coupling two or more of them, the further apart the better, and to analyse their combined signals.
An interferometer is a system which can avoid increased expenses due to the large size of the receiver. It consists of two or more elements of large antennae. By connecting them in a special fashion, it is possible to artificially create a larger telescope.
The European hub for what is called Very Long Baseline Interferometry (VLBI) is situated in Dwingeloo in the Netherlands, at the Joint Institute for VLBI in Europe, JIVE.