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For centuries, people have marveled at the aurora borealis, which illuminates the sky in shades of green, red, and purple. But these light phenomena are more than just a symbol of beauty—they reflect the powerful forces that shape space weather. The aurora borealis are created when charged particles from the Sun interact with Earth’s upper atmosphere. But another unseen force also plays a key role in space weather.
Electrojets are huge electrical currents that circulate around the Earth's poles, carrying nearly a million amperes per second. Changes in their activity can disrupt communications, affect satellites, and even cause power outages. Scientists still have many questions about how these currents form, how they change, and how they interact with Earth's magnetic field.
EZIE mission: studying electrojets
To find answers, NASA is preparing to launch a new mission – Electrojet Zeeman Imaging Explorer (EZIE)The ambitious project will use three CubeSats to study electrojets in detail. Scientists hope that EZIE observations will help improve space weather forecasting, which will protect astronauts, satellites and power systems on Earth.
Electrojets are part of a vast electrical system that extends nearly 100 miles from Earth into space. The interaction of the solar wind with our planet's magnetic field generates current flows that travel through the upper atmosphere, especially in the polar regions. These currents can change rapidly, causing sudden changes in Earth's magnetic field that ground-based systems can't always handle.
"EZIE is the first mission dedicated solely to the study of electrojets, and it uses a completely new measurement technique," – notes Larry Koepko, EZIE mission scientist from NASA's Goddard Space Flight Center.
Previous studies of electrojets have been based on ground-based observations and isolated satellite data. While these studies have provided valuable information, they have left many questions about the behavior of electrojets. The EZIE mission aims to fill these gaps and create a more complete picture of their evolution.
Observation of the behavior of electrojets
The EZIE mission will launch three small CubeSats, each about the size of a carry-on suitcase, into Earth-synchronous orbit. They will travel in a “pearls on a string” formation, flying 350 miles above the poles. Each satellite will observe the same region of the atmosphere with a small time lag of two to ten minutes. This will allow scientists to see how the electrojets change over short periods of time.
Each CubeSat is equipped with Microwave electrojet magnetometer – an instrument developed at NASA’s Jet Propulsion Laboratory that measures the strength and direction of electrojets. Normally, oxygen molecules in the atmosphere emit microwaves at a frequency of 118 gigahertz. But under the influence of strong magnetic fields (as in the case of electrojets), this radiation is split – a phenomenon known as Zeeman effectBy analyzing this effect, EZIE will be able to determine the behavior of electrojets in real time.
A breakthrough in space weather science
One of the biggest challenges in studying electrojets is their location: they occur in a region of the atmosphere that is too high for airborne probes but too low for traditional satellites. EZIE solves this problem by using remote measurements, which allow us to analyze electrojets without having to pass directly through them.
"Using the Zeeman effect to map the magnetic fields of currents is a real breakthrough," – notes Sam Yee, principal investigator of the EZIE mission from the Johns Hopkins University Applied Physics Laboratory.
The technology used in EZIE was refined in previous NASA missions, such as TEMPEST-D and CubeRRT, that investigated Earth's weather systems.
Global Public Engagement Initiative
NASA is also enlisting students and volunteers in the EZIE mission. The community science initiative will distribute dozens of magnetometer kits to schoolchildren in the U.S. and volunteers around the world. Participants will measure variations in the Earth's magnetic field, allowing scientists to compare ground-based data with EZIE's space-based observations.
“EZIE scientists will collect data from space, and students will collect data from the ground,” – explains Nelly Mosavi, EZIE project manager.
Launch during solar maximum
EZIE will launch in March 2025 aboard a SpaceX Falcon 9 rocket from Vandenberg Air Force Base in California. The mission coincides with the peak of the Sun’s 11-year solar activity cycle – solar maximumDuring this period, solar storms and other phenomena intensify the electrojets, making them easier to study.
"It's best to launch a mission during solar maximum," – says Kepko. "Electrojets respond directly to solar activity."
A new stage in space weather monitoring
EZIE will work alongside other NASA missions, such as PUNCH (Polarimeter to Unify the Corona and Heliosphere), which will study the interaction of the solar wind with the Earth. This project demonstrates the important role of CubeSat minisatellites in modern space exploration.
"This mission would have been impossible ten years ago," – adds Kepko. "It pushes the boundaries of what's possible, and we can't wait to see what we discover."
EZIE can revolutionize space weather forecasting, helping to protect both technology in orbit and infrastructure on Earth.
