NASA scientists have discovered a third global energy field around the Earth. Ambipolar electric field drives charged particles into space above the poles
It is known that there are two main global fields around the Earth — the gravitational field, formed by the planet’s mass, and the electromagnetic field, formed by the metals of the planet’s core. The hypothesis of a third field has been raised for decades, but a new NASA study has finally confirmed it with measurements.
«This electric field is bidirectional, or ambipolar, because it acts in both directions. Ions pull electrons down with them when they are lowered by gravity. At the same time, electrons lift ions to higher heights as they try to escape into space,», — NASA said.
Starting in the 1960s, spacecraft that flew over the Earth’s poles found many more particles escaping from the atmosphere into space than expected. This «polar wind» was strangely composed of particles that traveled at supersonic speeds, although they remained cold, contrary to expectations. Scientists speculated that this might be due to a phenomenon they called the ambipolar electric field.
According to the hypothesis, this field should begin at an altitude of about 250 km above the poles. It is at this height in the atmosphere that electrons are easily ejected from hydrogen and oxygen atoms, leaving a positively charged ion. These ions are much heavier than electrons, so if gravity were the only force acting on them, they would eventually fall down and the electrons would fly out into space.
But because ions and electrons have opposite charges, they continue to be attracted to each other. This has the end result of expanding the «scale height» atmosphere above the poles, essentially making it denser higher up.
This ambipolar electric field would be extremely weak and could only be detected at distances of hundreds of kilometers, so no instrument has ever been sensitive enough to pick it up. To test the hypothesis once and for all was the goal of NASA’s Endurance mission, which produced the results.
The mission culminated in a launch on May 11, 2022, from the world’s northernmost rocket launch site, located on the Svalbard archipelago, north of Norway. There, Endurance went on a 19-minute mission to study the field.
On-board instruments measured changes in electrical potential from the altitude at which the field is supposed to start to the maximum altitude it reached — 768 km. They did indeed detect a change of 0.55 V.
«Half a volt — is almost nothing, about the size of a watch battery. But that’s exactly what you need to explain the polar wind»,” says Glynn Collinson, principal investigator for the Endurance mission.
It doesn’t sound very powerful, but for hydrogen ions, the most abundant type in the polar wind, this electric field has produced a force more than 10 times greater than gravity, which helps launch them into space at supersonic speeds. Oxygen ions also receive a significant boost. The experiment also found a 271% increase in the height of the ionosphere.
Now that this electric field has finally been discovered, scientists can begin to explore how it has affected atmospheric changes throughout Earth’s history. The study was published in the journal Nature. A popular description of the study is presented in a NASA publication at the link below, and in a video.
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