Recordings from space have captured the unpleasant noise, which may be heard by extraterrestrials.
We already know the planet emits a quiet hum, most likely caused by our continuously moving oceans, or our turbulent atmosphere. The radio waves that cause the screeching sounds are created by particles that collide as the solar wind passes through the earth’s magnetic field.
New data from the European Space Agency’s Cluster mission show that the radio waves, called Auroral Kilometric Radiation, burst into space from the earth in narrow, flat beams.
New technology has enabled researchers to pinpoint exactly where the noise is coming from. Scientists located 12,000 spots around the earth that send out the radio waves, each is about the size of a large city.
So why don’t we hear them? A charged atmospheric layer called the ionosphere blocks the radio waves, preventing them from reaching the earth. But that doesn’t mean the waves aren’t strong.-they are 10,000 times greater that the strongest military signal, that’s enough to drown out every radio station on the planet.