First discovery of electric field surrounding Earth

This invisible energy field, called a dipole electric field, was detected by NASA's Endurance suborbital rocket.

The dipole electric field was hypothesized by scientists 60 years ago and is believed to play a key role for the Earth, similar to the magnetic field and gravity.

Scientists hope that studying dipole electric fields will help them better understand how planetary atmospheres evolve and function. The team published their findings in the journal Nature on August 28.

Ultraviolet radiation from the Sun interacts with atoms in a layer of Earth's atmosphere called the ionosphere (located 60–300 km above the ground), causing them to lose electrons and turn into ions. In theory, this process creates a weak electric field around the planet, which exists in the form of a 'polar wind,' or stream of particles that pours from Earth's atmosphere into space.

Clues to the existence of such electric fields were first detected in 1968 by spacecraft orbiting the South Pole and the North Pole.

Researchers predict that some of Earth's atmosphere is lost to space, especially after it is heated by sunlight.

But polar winds contain cold particles that are not heated, yet still move at speeds that break the sound barrier. So something must be sucking these particles out of the atmosphere.

Researchers launched the Endurance rocket from the launch site in Svalbard near the North Pole to investigate the origins of polar winds. The rocket reached an altitude of 768.03 km above the ground before landing in the Greenland Sea 19 minutes later.

The data Endurance collected over a 318-mile range showed a voltage change of 0.55 volts, about the strength of a watch battery. This voltage difference pushes hydrogen ions, the most abundant particles in the solar wind, with a force 10.6 times stronger than gravity, strong enough to propel atmospheric particles into space at hypersonic speeds. It's like a conveyor belt that lifts the atmosphere into space.

Jessica Tanner

Update 06 September 2024