NASA Johnson Pilots Chase Moon’s Shadow for Eclipse Science

During the Aug. 12 total solar eclipse over Europe, scientists aimed to study a long-standing mystery: why the Sun’s outer atmosphere, the corona, is far hotter than its visible surface. Capturing the data they needed meant being in exactly the right place at exactly the right time. Pilots from NASA’s Johnson Space Center flew the WB-57F high altitude research aircraft from Ellington Field in Houston to Iceland, their base for flying through the path of totality to give scientists a clearer view of the Sun’s corona. A total solar eclipse provides a unique opportunity to examine the corona because the Moon temporarily blocks the Sun’s bright surface, revealing its fainter outer atmosphere. Observations collected during this brief window can help scientists better understand how energy and material move through the corona and away from the Sun, improving our understanding of space weather. At about 50,000 feet, the WB-57F flew above most clouds, dust, and water vapor that can interfere with observations from the ground. The altitude reduced atmospheric interference while also allowing the science instruments to observe infrared wavelengths that are largely absorbed lower in Earth’s atmosphere. Capturing those observations required careful coordination between scientists and the flight crew. Before the mission, teams calculated where the aircraft needed to be as the Moon’s shadow moved across the North Atlantic. “Going into a mission like this takes a huge team. It starts with the science team establishing the requirements, and then we work closely with them for months leading up to the mission,” said Tom Parent, NASA WB-57F pilot. “We rely heavily on our maintenance team to get the instruments serviced, prepared, loaded onto the aircraft, and flight tested. It’s a huge team effort to get an aircraft like this up there to image and achieve these objectives.” During totality, NASA WB-57F pilot John Gustine positioned the aircraft along the eclipse path to maximize time in the Moon’s shadow and give scientists as much opportunity as possible to collect data. From the back seat, Cary Klemm, sensor equipment operator for NASA’s WB-57F, controlled the camera systems, adjusting focus and exposure times while tracking features of interest throughout totality. With the cameras capturing observations throughout the brief window, every second mattered. “Every image is another piece of data that could reveal something new about the Sun,” Klemm said. What scientists can learn from those observations reaches far beyond the eclipse itself. The Sun’s corona is made of plasma shaped by magnetic fields, and many of the same physical processes occur elsewhere in the universe. “The NASA WB-57F’s unique capabilities of high-altitude flight were truly crucial in providing access to these valuable wavelengths during an eclipse whose path crossed mostly over the ocean in an area where clouds are common,” said Amir Caspi, principal investigator for the study at Southwest Research Institute in Boulder, Colorado. “We could not have achieved this success without this platform, and all of the efforts of the many intrepid ground, air, and science crew members.” The data gathered during the flight will give scientists another opportunity to investigate the Sun and the processes that influence the space environment around Earth. View images and videos from NASA’s eclipse mission.