Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2020 May 2
the early days of radio and television
we have been freely
signals into space.
For some time now, we have been
A large radio telescope at Ohio State University known as
affectionately The Big Ear
was one of the first listeners.
The Big Ear was
about the size of three
football fields and consisted of an immense metal ground plane with
two fence-like reflectors, one fixed and one tiltable.
It relied on the Earth's
rotation to help
scan the sky.
This photo, taken by former Big Ear student volunteer Rick Scott,
looks out across the ground plane toward the fixed reflector with the
radio frequency receiver horns in the foreground.
Starting in 1965, the Big Ear
was used in an ambitious survey of the radio sky.
In the 1970s, it became the first telescope to
continuously listen for
signals from extraterrestrial civilizations.
For an exciting moment during August 1977 a very
strong, unexpected signal,
the Wow! Signal,
was detected by the Big Ear.
heard only once,
the source of the signal could not be determined.
In May 1998
the final pieces of the Big Ear were torn down.
Authors & editors:
Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
A service of: ASD at NASA / GSFC
& Michigan Tech. U.