Each time the Moon covers the Sun during a total solar eclipse — darkening daytime skies and briefly revealing the Sun’s ethereal outer atmosphere, the corona — it presents new opportunities to better understand our star and its influence on Earth.
On Wednesday, Aug. 12, as the next total solar eclipse sweeps over Greenland, Iceland, and Spain, NASA-funded science teams will be chasing the Moon’s shadow with a high-altitude jet and scientific balloons to investigate the Sun’s dynamics and how the temporary darkening of our skies affects our atmosphere.
“From our unique perspective on Earth during a total solar eclipse, scientists can study the Sun’s corona in a way we can’t from anywhere else in the solar system,” said Kelly Korreck, eclipse program manager at NASA Headquarters in Washington. “The Sun impacts our daily life, satellites, and astronauts in space, and we can take advantage of this moment to advance our understanding of that influence.”
Soaring in the nose cone of NASA’s WB-57 high-altitude research aircraft is a suite of four cameras to take high-resolution images of the corona in several different wavelengths of visible and infrared light. Part of an instrument developed by the NASA Scientifically Calibrated In-Flight Imagery (SCIFLI) team at NASA’s Langley Research Center in Hampton, Virginia, the cameras will capture at least 20 images per second, recording structures, outflows, and rapid changes in the corona during the total solar eclipse.
With these images, scientists hope to learn more about the formation of prominences (solar material that gets suspended above the Sun’s surface), better understand the corona and how it gets heated to nearly a million degrees, and investigate how material in the corona and the solar wind are related, which flows out from the Sun across the solar system.
By chasing the Moon’s shadow, the jet will extend how long the cameras can observe the corona. On the ground, the longest anyone will be able to see the corona is two minutes and 18 seconds. But flying along the eclipse path at 460 miles per hour, the jet’s view of the corona will last nearly three minutes.
NASA’s WB-57 will fly at 50,000 feet, above any clouds that might obscure the view of the corona from the ground. The altitude also allows the cameras to observe some infrared wavelengths that get absorbed by the lower atmosphere before reaching the ground, and the corona only has been observed in those wavelengths a few times before.
The instrument, called SCIFLI Multispectral Airborne Imager, or SAMI, also flew on a WB-57 during the total solar eclipse on April 8, 2024, providing valuable imagery and information about the corona. However, the study’s principal investigator, Amir Caspi of the Southwest Research Institute in Boulder, Colorado, says each total solar eclipse provides new opportunities to learn more about the corona.
“The Sun is always changing,” Caspi said. “Every eclipse is different. So we could see things we didn’t see before. And we learn from each eclipse how to better observe the next one.”
Caspi’s team also is making some enhancements for the 2026 campaign based on lessons learned in 2024. For example, the team will adjust exposure times to better capture bright features that were overexposed in 2024 imagery. They will also leverage software developed since 2024 to process and analyze the data sooner than before.
The experiment is funded by NASA’s Heliophysics Low Cost Access to Space Program.
When a total solar eclipse suddenly turns daytime skies dark, our atmosphere changes in ways we don’t yet fully understand.
The NASA-supported Nationwide Eclipse Ballooning Project, led by Angela Des Jardins at Montana State University, is sending students from several U.S. universities to Iceland and Spain to launch scientific balloons before, during, and after the eclipse to better understand those changes.
In Iceland, two teams will launch a total of 80 balloons starting 18 hours before the eclipse until eight hours afterward to study how the eclipse affects Earth’s “boundary layer,” the part of the atmosphere that touches the ground. The thickness of the boundary layer changes depending on factors such as surface temperature and moisture in the air.
Previous balloon flights during solar eclipses in October 2023 and April 2024 showed that the boundary layer collapsed, or decreased in thickness, in locations with clear skies but not where there were cloudy skies. Scientists wonder whether that will be different in Iceland in 2026. Changes in the boundary layer are driven by the day-night cycle. However, in Iceland in August, the days are long and nights are short, so the nighttime influences might not be as strong as in 2023 or 2024.
“Will this eclipse be able to collapse the boundary layer?” said Matthew Bernards, a chemical engineering professor at the University of Idaho, who leads one of the Iceland teams.
In Spain, three balloon teams will launch a total of six balloons with 360-degree cameras to image the eclipse shadow from above. These balloons also will include instruments designed to measure levels of ozone in the atmosphere, which requires sunlight to form. Similar balloon experiments showed that ozone decreased during totality in April 2024. Scientists wonder whether there will be differences with this eclipse, particularly since it happens at a later time of day and during a different season.
While the total solar eclipse won’t be visible in the U.S., some parts of the country will be able to see a partial solar eclipse. Learn more about where to see the eclipse and how to view it safely.
by Vanessa Thomas
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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