15 September, 2024
The American space agency NASA says it has confirmed the long-suspected existence of an electric field that surrounds Earth.
A rocket named Endurance gathered the information that led to the confirmation. Endurance launched from Norway on May 11, 2022. The launch site was the closest possible to the North Pole.
Endurance reached a top altitude of 768 kilometers. The rocket captured data on the electric field during its 19-minute flight before splashing down in the sea, off the coast of Greenland.
NASA says that since the 1960s, spacecraft flying over Earth's poles have recorded collections of particles flowing from the planet's atmosphere into space. But the cause of these outflows long remained a mystery. Scientists lacked the technology and tools to confirm an electric field and further explore it.
But the development in recent years of new observation methods and instruments led NASA to plan the Endurance mission. So the agency built the rocket and a new data instrument and planned the launch.
NASA scientist Glyn Collinson, an expert in space instrument design, led the Endurance mission.
Collinson explains in a video that scientists believe the electric field they searched for was one of three energy fields affecting Earth. The others are gravitational and magnetic. Scientists are calling the third energy field the “ambipolar electric field.”
A NASA statement says scientists believe the ambipolar field is an influential driver of the “polar wind.” They described the wind as “a steady outflow of charged particles into space that occurs above Earth's poles.” Scientists believe the ambipolar electric field counteracts some of the effects of gravity.
This electric field lifts the charged particles in Earth's upper atmosphere “to greater heights than they would otherwise reach,” NASA said. Scientists had theorized this electric field began at around 250 kilometers high. This is where atoms in our atmosphere break apart into negatively charged electrons and positively charged ions. This activity helps form a part of Earth's atmosphere known as the ionosphere.
NASA noted the Endurance mission permitted researchers to successfully identify and measure “a planet-wide electric field thought to be as fundamental to Earth as its gravity and magnetic fields.” A study describing the team's results recently appeared in the publication Nature.
NASA said studying the ambipolar electric field is important because it “may have shaped our planet's evolution in ways yet to be explored.” In addition, the agency said further study of this field can help scientists better understand other planets and possibly find ones with conditions that may support life.
Leader Collinson said that, during the mission, the instrument on the rocket was able to measure an electrical voltage of 0.55 volts. He said this level is very low, about the same voltage used to power a watch battery. But, he noted that 0.55 volts was “just the right amount” to explain the outflows of particles driving the polar wind.
Collinson said he finds the results “incredibly important” because the newly confirmed electric field can counter the effects of gravity and “basically lifts the skies up.” He described the field as a kind of “conveyor belt that's lifting this atmosphere up into space.”
Alex Glocer is a project scientist for the Endurance mission and was a co-writer of the study. He said he agrees with those findings. “That's more than enough to counter gravity – in fact, it's enough to launch them upwards into space at supersonic speeds,” Glocer said. Supersonic describes speeds that are greater than the speed of sound.
The team said the study results suggest the ambipolar electric field also greatly increases the density of the ionosphere at higher atmospheric positions.
Collinson said, “Any planet with an atmosphere should have an ambipolar field. Now that we've finally measured it, we can begin learning how it's shaped our planet as well as others over time.”
I'm Bryan Lynn.
Bryan Lynn wrote this story for VOA Learning English, based on reports from NASA.
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Words in This Story
pole – n. either part of an axis of a sphere and especially of Earth's axis
counteract – v. the reduce a bad effect of something else
fundamental – adj. relating to the most important or main part of something
evolution – n. a gradual process of change and development
battery – n. an object that provides electricity for things such as radios, toys, cars, etc.
conveyor belt – n. a continuous moving piece of rubber or metal that is used to transport objects from one place to another