What is the highest radio frequency used for radio astronomy?
Answer Hello Green The link you provided has some interesting notes regarding radio astronomy, including one comment predicting that over time the distinctions between optical and radio astronomy will disappear. True, almost all astronomy observes Electromagnetic (EM) radiation: Radio and Light and X-Rays are all examples of EM radiation. So, speaking pedantically, the highest frequencies used in ‘radio’ astronomy would be cosmic ray or x-ray observations. The link describes frequency allocations that could / should be protected from terrestrial emissions that can jam radio astronomy uses, and the highest they mention is that quantum transition spectral line at 3438 GHz (or 3.438 THz). Traditionally the equipment distinctions between optical techniques (mirrors, lenses, our eyes) and radio astronomy (metal antennas, electronic receivers) have defined the various sub-castes of astronomers. As the techniques multiply, the distinctions blur. For example, there is a fascinating neutrino de
