Nikola Tesla and The History of Radio Astronomy


One night, while working alone in his lab in Colorado Springs in the summer of 1899, Nikola Tesla began picking up signals with a highly sensitive receiver he had invented. He thought at first they might be caused by the sun, aurora borealis or earth currents, but then concluded they weren’t caused by atmospheric disturbances and must be extraterrestrial in origin. He observed Mars in the night sky and assumed it must be the source of the signals he was receiving.

He wrote in his journal: “I felt as though I were present at the birth of a new knowledge or the revelation of a great truth.”

Tesla’s interviews with the press resulted in sensational headlines, and since then his discovery of radio signals from beyond the earth has been the subject of great controversy.

About one hundred years after Tesla’s controversial discovery, two brothers – James and Kenneth Corum – one a physicist and the other an electrical engineer, launched an experimental and theoretical study to test a new theory. They knew Tesla’s original receiver was tuned to receive VLF (very low frequency) waves in the 8 to 22 KHz. range and set out to find the source of VLF signals originating from space during the summer of 1899. They discovered that Io, one of Jupiter’s moons, emits a 10 KHz signal as it passes through a torus of charged plasma particles surrounding the planet.

It is known among scientists that the ionosphere is opaque at these frequencies; but under certain conditions – such as sun spots – the earth’s magnetic field will create something known as an ‘ionospheric window’ in the lower VLF range. The Corums confirmed that this window could have been open during the time frame of Tesla’s experiments. NASA now states that both Jupiter and Saturn radiate intermittent signals toward the earth in the kilometric frequency range of Tesla’s receivers.

Kenneth and James Corum have provided solid scientific evidence not only that Nikola Tesla was observing real phenomena – that the signals he was picking up with his receiver were planetary in origin – but that Tesla had made the first successful observations in radio astronomy, more than 30 years before Karl Jansky, who is known as one of the founders of radio astronomy.

- Helen Hall





Nikola Tesla and The Planetary Radio Signals: Kenneth L. Corum and James F. Corum, Ph.D., 2003 retrieved from

Images courtesy of NASA and ESA (European Space Agency)