Earth Emits Screams in Space

Astronomers recorded series of sounds resembling chirps and whistles, generated high above Earth.

The phenomenon was called the Auroral Kilometric Radiation (AKR) and was recorded with the help high-flying satellites. The emission is created as the solar particles crash with the magnetic field of the Earth and is also related to the appearance of the colorful aurora that lights the sky.

AKR was discovered since the 1970s and was believed to travel out into space in an ever-widening cone. But the recent analysis from the European Space Agency's Cluster mission showed that these radio waves are emitted in a narrow plane. Scientists identified the origin of the AKR bursts in Earth magnetic field, formed above the light of the aurora.

The radio waves do not reach the ground because of the protection of the ionosphere, the upper part of Earth’s atmosphere. They are also known to be 10 000 times more powerful than the strongest military radar system and may well overpower the transmission from all radio stations.

Scientists say that AKR is emitted not only by Earth but other planets, like Jupiter and Saturn, the biggest gas planets in the Solar System. This knowledge is valuable in investigating planets and stars but astronomers will need much larger radio telescope. Scientists also have a great chance to comprehend the magnetic fields of the planets and search for other planets around the stars. In future, it might be even possible to find alien worlds by listening for their emissions.

Earth is also presumed to emit low-frequency sounds, resembling humming that is believed to come from the oceans or rolling atmosphere.