Produced by: Tarun Mishra
NASA has confirmed the existence of a long-hypothesized electrical field called the "polar wind," which explains how Earth's atmosphere escapes above the north and south poles.
The field was first proposed over 60 years ago when spacecraft detected particles escaping Earth's atmosphere at supersonic speeds, though they showed no signs of being heated by sunlight.
The discovery was made possible by NASA's Endurance mission, which launched a suborbital rocket in May 2022 from Svalbard, Norway, equipped with sensors designed to detect the weak electrical field.
Credit: NASA
The rocket reached an altitude of 477 miles and measured a slight voltage change of 0.55 volts, which was sufficient to confirm the presence of the polar wind.
Credit: NASA
The field forms around 150 miles above Earth, where ions and electrons separate, creating an electric field that counteracts gravity, allowing particles to escape into space.
Hydrogen ions experience a push from the field, which is 10.6 times stronger than gravity, propelling them into space at supersonic speeds. Oxygen ions also receive a speed boost from the field.
The discovery suggests that similar electrical fields may exist on other planets, such as Venus and Mars, and could provide insights into the evolution of Earth's atmosphere and oceans. The findings were published in Nature on August 28, 2024.