https://www.youtube.com/watch?v=f7BCzm4IGpY As the eclipse laid a swath of darkness across the heart of the United States, thousands of amateur photographers pointed phones and cameras skyward to memorialize the occasion. The images together comprise a mosaic of stellar imagery spanning more than an hour and a half, and give scientists a chance to study a feature of the sun still shrouded in mystery: the corona. The delicate atmosphere of our home star, the corona is a wispy collection of charged particles that extends millions of miles above the sun's surface. It's also much hotter than the surface itself, a phenomenon that scientists still don't completely understand. The Eclipse Megamovie, a collaboration between the University of California, Berkeley and Google, is giving astronomers a trove of data to analyze the corona by assembling images from photographers along the path of totality. They've just released the first, preliminary glimpse of the movie as they begin to stitch the shots together. The result is a series of shots of the occluded sun, with the corona on full display. Each clip is time-stamped, and they all come together in a kind of flip-book view of the sun as the moon's shadow races across the country. The movie will be filled out with many more images as the researchers continue to add them; they say that well over 1,000 people participated. While researchers are able to study the corona using radio wave emissions, this will be their best opportunity to gather data in the visible spectrum, which could bring new insights into its behavior.