When people witness a total solar eclipse from within the path of totality, they become captivated by the awe-inspiring beauty of the sun’s corona.
This is the only time when it is visible to the naked eye and can be captured in photographs.
However, there is another layer known as the chromosphere that becomes visible during the total eclipse. The chromosphere is a layer of superheated gas (plasma) that lies between the sun’s surface, known as the photosphere, and the corona. Within this layer, jets and plumes of plasma flow as they make their way into space.
However, there is an issue. “Solar physicists are uncertain about the amount of the sun’s mass that is being emitted from the sun,” stated Laura Peticolas, a researcher from Sonoma State University in California, who is leading the Eclipse Megamovie 2024 project funded by NASA, in an interview with Space.com. “Total solar eclipses offer invaluable insights to the solar community that are simply unattainable through any other means.”
The main goal of the Eclipse Megamovie 2024 project is to develop a publicly accessible dataset that will assist solar physicists in addressing a crucial issue related to plasma dynamics during the total solar eclipse on April 8. The plasma from the sun’s photosphere flows into space, but it is not possible to determine its distance with the help of NASA’s space-based Solar Dynamics Observatory. To protect the optics from any potential damage caused by the sun’s light, an occulter is used to block the bright disk of the sun. However, in doing so, it also blocks the chromosphere and lower corona. That’s where all the excitement takes place. “There’s a region that is not easily observable with NASA satellites in visible light,” explained Peticolas. “By capturing the scattered visible white light, we can calculate the density of the plasma as it moves out. This presents us with a valuable opportunity.”
That phenomenon can only be observed during a total solar eclipse. Approximately 100 dedicated citizen scientists, each equipped with their own DSLR camera and an equatorial mount to account for Earth’s rotation, will capture approximately 1,200 images of the corona and chromosphere. Furthermore, the data generated by this project will be used for scientific analysis. Additionally, the findings will be compared to the data collected during the previous total solar eclipse in the United States, which occurred in 2017.
The project received support from Google and involved 2,000 smartphone owners who downloaded an app to capture and upload more than 34,000 images of the eclipsed sun. The endeavor to create a video using images gathered by citizen scientists along the path proved to be a success in terms of outreach. However, it did not yield the scientific value that was initially anticipated. “We didn’t insist on people having equatorial mounts, so the sun would move within the field of view in their images,” explained Peticolas. “We provided them with four different exposure times as an example, expecting people to experiment with them. However, most individuals did not make any changes.” Peticolas had high expectations for the number of exposure times in the thousands of images, hoping for at least 90 different ones. This is a standard achieved by experienced eclipse photographers during totality. “That didn’t happen, so we didn’t have enough data to generate high-quality images,” explained Peticolas. However, scientists were able to discover evidence of a plasma plume in our data. Nevertheless, certain adjustments were required for 2024.
Now, thanks to improved equipment and the participation of 100 individuals who are capturing and sharing higher quality images in 50 different exposures, there is great anticipation for the Eclipse Megamovie 2024 to deliver even more intricate and captivating results.
For this upcoming event, we have prepared an increased number of photos and a wider range of exposure times. Moreover, the sun is nearing, or potentially already at, solar maximum, resulting in a greater number of visually stunning processed images compared to 2017. The solar maximum, which represents the peak of the sun’s magnetic activity in its 11-year cycle, holds great significance. During this time, citizen scientists have the opportunity to observe and document more activity in the corona and chromosphere compared to the previous year of 2017. “In 2017, we simply lacked the variety of exposure times needed to capture a high dynamic range image of the solar corona,” stated Peticolas. She is optimistic about obtaining a wide range of images from an additional 2,000 volunteers using DSLR cameras, as well as from the 100 trained photographers. “This time we will.”
