I’d hazard a guess that few of us are heliophysicists, but we’ve nevertheless been invited to become citizen scientists by using just our phone cameras to capture the total solar eclipse on Monday, April 8. In preparation for the upcoming event, students and faculty at Western Kentucky University (WKU) have developed a free new app called SunSketcher that allows users to photograph the eclipse, requesting public participation to allow the team to gather data about the structure of the sun.
Funded by NASA, SunSketcher invites those within or close to the path of totality to simply take photos of the eclipse on their smartphones. Once activated, the app will automatically capture specific points of “contact,” or overlap, between the sun and the moon so users don’t have to worry about taking a photo at the perfect moment. The app is scheduled to take photos during the exact moment that “Baily’s Beads” are in position — a stunning visual phenomenon in which light from the sun’s edges is visible only during the start and end of the total eclipse. But how exactly are smartphone photos of a solar eclipse going to help anyone?
The crux of the project is to learn more about the sun’s internal structure based on the irregularities on its surface. Just as the moon appears spherical to the naked eye but is rife with craters and bumps, the sun looks like a perfect circle but is actually somewhat oblate, meaning partially flattened at both poles.
“We expect to find the Sun to be slightly oblate, based on the fact that it is a rotating ball of gas and will therefore experience centripetal forces,” Hugh Hudson, a professor of physics and astronomy at WKU who serves as the science advisor for SunSketcher, said in an email to Hyperallergic. Hudson explained that because the sun is not a solid object, different parts of its surface rotate at different speeds, likely resulting in an oblate shape.
“The equatorial region is going about 10% faster than the mid-latitudes,” Hudson said. “We have only indirect information about the Sun’s interior, and this matters for the oblateness, but we shall see [with this forthcoming eclipse].”
Given enough participation from the public, photos of the eclipse taken through SunSketcher will help scientists accurately calculate not only the sun’s oblateness, but also how the force of solar gravity impacts the orbit and rotation of our solar system’s inner planets. Images submitted to the app will be geotagged but remain otherwise anonymous and added to a massive database for researchers to analyze alongside lunar maps generated by the Lunar Reconnaissance Orbiter spacecraft.
Users will get to keep their photos, as well. And since the phone should be leaned up against a hard surface and left undisturbed during the eclipse, don’t forget proper eye protection while you watch along on this special day!
