Ground-Based Radio and Millimeter Observatories

Ground-based facilities that observe the sky at radio and millimeter wavelengths rather than visible light: the Arecibo Observatory in Puerto Rico, the Atacama Large Millimeter Array in Chile, the Very Large Array in New Mexico, and the Event Horizon Telescope, a global network of radio observatories linked to act as a single Earth-sized instrument. Belongs here: an Earth-based facility whose instruments detect radio or millimeter-wavelength radiation. Does not belong here: an Earth-based facility observing in visible light, grouped under Ground-Based Optical Observatories, or a facility in space, grouped under Space-Based Observatories.