How many do there have to be to be seen? (Score 1)

The article speaks only of finding a single molecule!

Does anyone out there know the physics in enough detail to let a person (me) who does not have enough physics in on HOW the radio telescope gives them info on the structure of a molecule lightyears away?

Or do they need millions of these things doing whatever they do to generate radio waves?

Enquiring minds want to know ...