In 2013, NASA's Cassini spacecraft captured this image of Earth from Saturn. Seen here, our planet is 898 million miles away (1.44 billion kilometers) and appears as a blue dot at center right. NASA/JPL-Caltech/Space Science Institute hide caption

itoggle caption NASA/JPL-Caltech/Space Science Institute

In this rare image taken on July 19, 2013, the wide-angle camera on NASA's Cassini spacecraft has captured Saturn's rings and our planet Earth and its moon in the same frame. NASA/JPL-Caltech/Space Science Institute hide caption

itoggle caption NASA/JPL-Caltech/Space Science Institute