Scientists have finally detected and measured a faint, elusive energy field enveloping our planet known as the ambipolar field. First theorized over 60 years ago, this electric field’s discovery marks a significant advancement in our understanding of Earth’s behavior and evolution.
“Any planet with an atmosphere should have an ambipolar field,” says Glyn Collinson, an astronomer at NASA’s Goddard Space Flight Center. “Now that we’ve measured it, we can start exploring how it’s influenced Earth and other planets over time.”
Earth is far from a static mass floating in space. It’s surrounded by various fields, including gravity, which holds the atmosphere close to the surface, and the magnetic field, which shields the planet from solar wind and radiation while also preventing the atmosphere from dissipating into space.
In 1968, a new phenomenon was described by scientists. Spacecraft flying over Earth’s poles detected a supersonic wind of particles escaping from the atmosphere, leading to the hypothesis of a third energy field—the ambipolar field.
“The ambipolar field is a force of chaos,” Collinson explains. “It counteracts gravity and pulls particles into space. Until now, we couldn’t measure it due to a lack of technology. That’s why we developed the Endurance rocket ship to hunt for this elusive force.”
The ambipolar field is expected to emerge at around 250 kilometers (155 miles) above Earth’s surface in the ionosphere, where extreme ultraviolet and solar radiation ionize atmospheric atoms, creating positively charged ions. While lighter electrons try to escape into space, heavier ions sink toward the ground. The resulting electric field, known as the ambipolar field, tethers these particles together, balancing the forces acting on them.
This field is weak, which is why Collinson and his team designed sensitive instrumentation to detect it. The Endurance mission, launched in May 2022, reached an altitude of 768 kilometers (477 miles) before returning to Earth with crucial data. The mission successfully measured a change in electric potential of just 0.55 volts—barely enough to power a watch battery—but sufficient to explain the polar wind.
This small charge exerts a force on hydrogen ions 10.6 times stronger than gravity, propelling them into space at supersonic speeds. Oxygen ions, which are heavier, are also lifted higher, increasing the ionosphere’s density at high altitudes by 271 percent compared to what it would be without the ambipolar field.
This discovery is just the beginning. The implications of the ambipolar field, including how long it has existed, what role it plays in shaping Earth’s atmosphere, and its influence on the planet’s evolution and life, remain largely unknown.
“This field is a fundamental part of how Earth functions,” Collinson says. “Now that we’ve measured it, we can start addressing some of these bigger and more exciting questions.”