In a few short hours, many in North America will be treated to a total solar eclipse. Beyond the novelty, scientists have much to gain from the experience. To this day, many aspects of the sun remain a mystery: What causes solar flares, when massive amounts of energy and plasma are ejected from the sun? Why is the corona, the solar atmosphere, actually hotter than the surface? The eclipse provides a natural experiment to test some of these questions. The moon is perfectly sized to block out the entire surface of the sun, leaving the corona, which is some million times fainter in our view.
The next total solar eclipse visible in North America will take place in 2024.
image: National Geographic