On Monday, August 21 a large swath of North America will be treated to a spectacular display of celestial magic, a total eclipse of the sun. For the first time in 99 years from coast to coast across the entire continental U.S., daytime will become total darkness for about two minutes in a 70-mile wide band stretching from Oregon to South Carolina. Those outside this path of totality will see a partial eclipse, as illustrated above in the lines parallel to the path of totality.
This marks an unusual opportunity for scientists to study features of the outer atmosphere of the sun that are usually obscured by its blinding brightness. The international space station, orbiting satellites, high-altitude balloons, and ground based telescopes will all be focused on this rare astronomical event.
In spite of the well-justified attention garnered by the Eclipse of 2017, the information gathered, as the eclipse transits the continent, is likely to provide only an incremental improvement in our understanding of the sun, its outer atmosphere, and surrounding regions of space. In contrast, another eclipse, observed by only a few ground-based astronomers using mostly marginal equipment, resulted in undoing mankind’s fundamental concept of the universe accepted as immutable fact for nearly 250 years. How this happened illustrates an important lesson in how we should judge what we think we “know” is so.