Two summers ago, on August 21, 2017, thousands of people from across the world witnessed the "Great American Solar Eclipse," the first total solar eclipse to occur exclusively over the continental United States since January 11, 1880. Now, stargazers are getting excited to watch the Sun disappear again for a brief period on July 2, 2019 — this time, the eclipse's narrow path will extend across the South Pacific all the way to Chile and Argentina.