Each time the Moon covers the Sun during a total solar eclipse (darkening the daytime skies and briefly revealing the Sun’s ethereal outer atmosphere, the corona), new opportunities present themselves to better understand our star and its influence on Earth.

On Wednesday, August 12, when the next total solar eclipse passes over Greenland, Iceland and Spain, NASA-funded science teams will chase the Moon’s shadow with a high-altitude jet and scientific balloons to investigate the dynamics of the Sun 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 lives, satellites and astronauts in space, and we can take advantage of this moment to advance our understanding of that influence.”

An array of four cameras rise in the nose cone of NASA’s WB-57 high-altitude research aircraft to take high-resolution images of the corona in several different wavelengths of visible and infrared light. As part of an instrument developed by NASA’s Scientifically Calibrated In-Flight Imaging (SCIFLI) team at NASA 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 bulges (solar material that remains suspended above the Sun’s surface), better understand the corona and how it heats up to nearly a million degrees, and investigate how coronal material and the solar wind, which flows from the Sun through the solar system, are related.

By chasing the Moon’s shadow, the jet will prolong the time that cameras can observe the corona. On land, the maximum time anyone will be able to see the crown is two minutes and 18 seconds. But flying along the eclipse path at 460 miles per hour, the plane’s view of the corona will last almost three minutes.

NASA’s WB-57 will fly at 50,000 feet, above any clouds that could obscure the view of the corona from the ground. The altitude also allows cameras to observe some infrared wavelengths that are absorbed by the lower atmosphere before reaching the ground, and the corona has only been observed at 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 of April 8, 2024, providing valuable images and information about the corona. However, the study’s principal investigator, Amir Caspi of the Southwest Research Institute in Boulder, Colorado, says that 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 were able to see things we didn’t see before. And from each eclipse we learn how to better observe the next one.”

The Caspi team is also making some improvements 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 the 2024 images. They will also take advantage of software developed since 2024 to process and analyze the data earlier than before.

The experiment is funded by NASA’s Low-Cost Heliophysics Space Access Program.

When a total solar eclipse suddenly darkens the daytime skies, our atmosphere changes in ways we don’t yet fully understand.

The National Eclipse Balloon Project, supported by NASA and led by Angela Des Jardins of Montana State University, is sending students from several American 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 from 18 hours before the eclipse to eight hours after 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 air humidity.

Previous balloon flights during the October 2023 and April 2024 solar eclipses showed that the boundary layer collapsed, or decreased in thickness, in places with clear skies but not where there were cloudy skies. Scientists wonder if that will be different in Iceland in 2026. The changes in the boundary layer are driven by the day-night cycle. However, in Iceland in August, the days are long and the nights short, so nighttime influences might not be as strong as in 2023 or 2024.

“Will this eclipse 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 photograph the shadow of the eclipse from above. These balloons will also include instruments designed to measure ozone levels in the atmosphere, which requires sunlight to form. Similar balloon experiments showed that ozone decreased during totality in April 2024. Scientists wonder if there will be differences with this eclipse, especially because it occurs at a later time of day and during a different season.

While the total solar eclipse will not be visible in the US, some parts of the country will be able to see a partial solar eclipse. Learn more about where to view the eclipse and how to view it safely.

by Vanessa Thomas
NASA Goddard Space Flight Center, Greenbelt, Maryland.