NASA has approved two heliophysics missions to explore the Sun and the system that drives space weather near Earth.
Together, NASA’s contribution to the Extreme Ultraviolet High-Throughput Spectroscopic Telescope Epsilon Mission, or EUVST, and the Electrojet Zeeman Imaging Explorer, or EZIE, will help us understand the Sun and Earth as an interconnected system.
Understanding the physics that drive the solar wind and solar explosions – including solar flares and coronal mass ejections – could help scientists predict these events, which can impact human technology and explorers in space.
The Japan Aerospace Exploration Agency (JAXA) leads the Extreme Ultraviolet High-Throughput Spectroscopic Telescope (EUVST) Epsilon Mission (Solar-C EUVST Mission), along with other international partners.
Targeted for launch in 2026, EUVST is a solar telescope that will study how the solar atmosphere releases solar wind and drives eruptions of solar material. NASA’s hardware contributions to the mission include an intensified UV detector and support electronics, spectrograph components, a guide telescope, software, and a slit-jaw imaging system to provide context for the spectrographic measurement.
The Electrojet Zeeman Imaging Explorer (EZIE) will study electric currents in Earth’s atmosphere linking aurora to the Earth’s magnetosphere – one piece of Earth’s complicated space weather system, which responds to solar activity and other factors. The Auroral Electrojet (AE) index is a common measure of geomagnetic activity levels, even though the details of the structure of these currents is not understood. EZIE will launch no earlier than June 2024.
“We are very pleased to add these new missions to the growing fleet of satellites that are studying our Sun-Earth system using an amazing array of unprecedented observational tools,” said Thomas Zurbuchen, associate administrator for science at NASA headquarters in Washington, US.
The EUVST mission addresses the recommendations of a July 2017 final report delivered by the multi-agency Next Generation Solar Physics Mission Science Objectives Team. EUVST will take comprehensive UV spectroscopy measurements of the solar atmosphere at the highest level of detail to date, which will allow scientists to tease out how different magnetic and plasma processes drive coronal heating and energy release.
EZIE is an investigation comprising a trio of cubesats that will study the source of and changes in the auroral electrojet, an electric current circling through Earth’s atmosphere around 60-90 miles above the surface and extending into the Earth’s magnetosphere. The interaction of the magnetosphere and the solar wind compresses the Sun-facing side of the magnetosphere and drags out the night-time side of the magnetosphere into what is called a “magnetotail.”
Auroral electrojets are generated by changes in the structure of the magnetotail. The same space weather phenomena that power the beautiful aurora can cause interference with radio and communication signals and utility grids on Earth’s surface, and damage to spacecraft in orbit.
“With these new missions, we’re expanding how we study the Sun, space, and Earth as an interconnected system,” said Peg Luce, deputy director of the Heliophysics Division at NASA. “EZIE’s use of instrument technology proven on Earth science cubesat missions is just one example of how science and technology development at NASA go hand in hand across disciplines.”
