The Big Ear, a radio telescope operated by Ohio State University as part of the SETI project, receives a radio signal from deep space; the event is named the "Wow! signal" from the notation made by a volunteer on the project.

The Ohio State University Radio Observatory was a Kraus-type radio telescope located on the grounds of the Perkins Observatory at Ohio Wesleyan University in Delaware, Ohio from 1963 to 1998. Known as Big Ear, the observatory was part of Ohio State University's Search for Extraterrestrial Intelligence (SETI) project. The telescope was designed by John D. Kraus. Construction of the Big Ear began in 1956 and was completed in 1961, and it was finally turned on for the first time in 1963.

A radio telescope is a specialized antenna and radio receiver used to detect radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency portion of the electromagnetic spectrum, just as optical telescopes are used to make observations in the visible portion of the spectrum in traditional optical astronomy. Unlike optical telescopes, radio telescopes can be used in the daytime as well as at night.

The Ohio State University is a public land-grant research university in Columbus, Ohio, United States. A member of the University System of Ohio, it was founded in 1870. It is one of the largest universities by enrollment in the United States, with nearly 50,000 undergraduate students and nearly 15,000 graduate students. The university consists of sixteen colleges and offers over 400 degree programs at the undergraduate and graduate levels.

The search for extraterrestrial intelligence is an expression that refers to the diverse efforts and scientific projects intended to detect extraterrestrial signals, or any evidence of intelligent life beyond Earth.