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NASA Discovers Earth’s Third Energy Field: The ‘Polar Wind’
Context:
NASA has identified a previously theoretical energy field called the ‘Polar Wind’, which has been hypothesised for 60 years.
- This field, fundamental to understanding Earth’s atmospheric processes, was detected using measurements from NASA’s Endurance mission.
Background
- In the 1960s, observations from spacecraft flying over the Earth’s poles detected streams of particles escaping into space at supersonic speeds.
- These particles were not heated by sunlight, suggesting an additional force was responsible. Scientists hypothesised the presence of a weak, invisible electric field, but technology at the time could not detect it.
- NASA’s Endurance mission, launched on May 11, 2022, from Svalbard, successfully measured the planet-wide electric field associated with the Polar Wind.
- This breakthrough confirmed the ambipolar field’s role in driving atmospheric escape and shaping the ionosphere.
Key Highlights:
- The Polar Wind is Earth’s third major energy field alongside gravity and magnetism. Although it is weak, it plays a crucial role in counteracting gravity and lifting atmospheric particles.
- It is believed to influence how Earth’s atmosphere evaporates, particularly at the poles.
- The Endurance rocket reached an altitude of 477 miles (768 kilometres) and detected a subtle 0.55-volt change in the electric field, confirming the presence of the polar wind.
- This ambipolar field increases the ionosphere’s density by 271%, helping to maintain its density at higher altitudes.
Mechanism of the Polar Wind:
- The electric field forms at around 150 miles (250 kilometres) altitude, where atmospheric atoms split into charged particles (electrons and ions).
- The field counteracts gravity, allowing particles to escape into space.
- It is described as a “conveyor belt” that lifts atmospheric particles, with hydrogen ions experiencing an outward force 10.6 times stronger than gravity.
Implications:
- The discovery aids in understanding atmospheric escape on other planets like Venus and Mars.
- The findings open up new avenues for exploring the evolution of Earth’s atmosphere and its effects on other planetary bodies.