A view of the Milky Way galaxy in microwaves is captured by the European Space Agency's Planck satellite. Credit: ESA/NASA/JPL-Caltech.
Astronomy specifically focused at the microwave portion of the electromagnetic spectrum is microwave astronomy.
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz (0.3 GHz) and 300 GHz.[1] This broad definition includes both UHF and Extremely high frequency (EHF) (millimeter waves), and various sources use different boundaries.[2] In all cases, microwave includes the entire super high frequency (SHF) band (3 to 30 GHz, or 10 to 1 cm) at minimum, with RF engineering often putting the lower boundary at 1 GHz (30 cm), and the upper around 100 GHz (3 mm).
