Caption: Arno Penzias (1933--2024) (right) and Robert Wilson (1936--) (left) with the Bell Labs radio telescope in Holmdel Township, New Jersey where in 1965 they fortuitiously discovered the cosmic microwave background radiation (CMB, blackbody temperature T = 2.72548(57) K (Fixsen 2009)), but at only wavelength 7.3 cm in the microwave band (fiducial range 0.1--100 cm, 0.01--10 cm**(-1)). The CMB is a nearly uniform radiation field coming to us from all directions.

Penzias and Wilson received 1978 Nobel Prize in Physics for their discovery.

It is de rigueur in this context to mention that to be sure that they weren't just detecting instrumental noise, they had to clean history's most famous pigeon guano out of their antenna.

Credit/Permission: NASA, 1962 (uploaded to Wikipedia by User:Bammesk, 2020) / Public domain.
Image link: Wikipedia: File:Horn Antenna-in Holmdel, New Jersey - restoration1.jpg.
Local file: local link: arno_penzias.html.
File: Astronomer file: arno_penzias.html.