Radiometer reference horn
Radiometer reference horns were a piece of advanced energy technology aboard NASA's Mariner 2 space probe when it was launched in the mid-20th century.

A schematic of the Mariner 2 spacecraft depicting the locations of the radiometer reference horns was stored in the 's library computer database. This database was accessed by the Talosians in 2254. ()

Energy technology (retconned)