Incredible views of Mercury passing in front of the Sun. Credit: Solar Dynamics Observatory Beyond Our Sight NASA Goddard | The Science Explorer

Fifty years ago, three NASA Astronauts embarked on a journey that would take them “Round the Moon and back." The Apollo 8 mission proved the performance of the command and service module. This historic mission launched on December 21, 1968 to demonstrate a lunar trajectory and was the first crewed launch of the Saturn V rocket. On Christmas Eve, Frank Borman, Jim Lovell, and Bill Anders were the first humans to orbit the Moon and the first to see an Earthrise above its surface. | NASA History