However, in any one location along April’s eclipse path, totality will last less than four and a half minutes – not long enough to watch the corona change. By staging observers all along the eclipse path, though, these NASA projects hope to essentially extend totality for over 90 minutes – the time it takes for the Moon’s shadow to cross from Mexico to Canada. Afterward, the projects will combine their images into “movies” revealing activity in the corona that would otherwise be hard to see.