Radio JOVE home page The Galactic Background Radiation The ever-
present sound of our galaxy by Dr. Leonard N. Garcia |When
making observations of Jupiter you may hear all kinds of radio
frequency interference. Most of the interference will likely be
of terrestrial origin and may be natural, like distant lightning
strikes, or man-made like power line "buzz" or radio stations.
There is however a type of interference that will be inescapable
and doesn't come from anything on Earth. It is the ever-present
galactic background radio noise. It can always be heard but not
always at the same strength. The discovery of the origin of this
background noise is usually marked as the birth of radio
astronomy. Karl Jansky, an engineer working for Bell Telephone
Labs, was assigned the task of locating sources of interference
in long distance radio-telephone communications. He built in
1931 in Holmdel, New Jersey an antenna operating at 20.5 Mega
Hertz which rotated horizontally like a merry-go-round. The
rotation of the anten