The research opens new avenues for understanding planetary atmospheres.
In a groundbreaking discovery, a long-suspected electric field around Earth has been observed to generate a kind of polar wind that propels particles into space at supersonic speeds. Scientists call this an “ambipolar electric field,” which is a weak phenomenon on a global scale-one theorized for the very first time more than 60 years ago. Recent observations from NASA’s Endurance rocket, published in Nature, confirm its existence and suggest it significantly influences Earth’s atmosphere, most especially over the poles.
According to NASA, the ambipolar electric field is a key driver of the “polar wind,” a steady outflow of charged particles into space that occurs above Earth’s poles. This electric field lifts charged particles in our upper atmosphere to greater heights than they would otherwise reach and may have shaped our planet’s evolution in ways yet to be explored.
Measurements from the rocket, NASA’s Endurance mission, have confirmed the existence of the ambipolar field and quantified its strength, revealing its role in driving atmospheric escape and shaping our ionosphere – a layer of the upper atmosphere – more broadly.
Understanding the complex movements and evolution of our planet’s atmosphere provides clues not only to the history of Earth but also gives us insight into the mysteries of other planets and determining which ones might be hospitable to life. The paper was published Wednesday, August 28, 2024, in the journal Nature.
“Something had to be drawing these particles out of the atmosphere,” said Glyn Collinson, principal investigator of Endurance at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the paper. Scientists suspected a yet-to-be-discovered electric field could be at work.
“It’s like this conveyor belt, lifting the atmosphere up into space,” Collinson added.
Endurance’s discovery has opened many new paths for exploration. The ambipolar field, as a fundamental energy field of our planet alongside gravity and magnetism, may have continuously shaped the evolution of our atmosphere in ways we can now begin to explore. Because it’s created by the internal dynamics of an atmosphere, similar electric fields are expected to exist on other planets, including Venus and Mars.
“Any planet with an atmosphere should have an ambipolar field,” Collinson said. “Now that we’ve finally measured it, we can begin learning how it’s shaped our planet as well as others over time.”
