Earlier this week, NASA celebrated the anniversary of Apollo 8, which served as the first human mission to leave low-Earth orbit and reach the Moon. During this mission, NASA's astronauts also provided a historical Christmas message from space.

Apollo 8 was NASA's first mission to send astronauts beyond Earth's vicinity to orbit the Moon. Its crew consisted of Frank Borman, William Anders and James Lovell.

Apollo 8's launch history
Fifty years ago on Dec. 21, 1968, Apollo 8 launched from Pad A, Launch Complex 39, Kennedy Space Center at 7:51 a.m. EST. Frank Borman commanded the crew of the Apollo 8 lunar orbit mission. James Lovell served as command module pilot and William Anders was the lunar module pilot. Apollo 8 was the first crewed Saturn V launch. Apollo 8 was supposed to be a test flight to simulate atmospheric re-entry from the Moon but never meant to go there. But then the Soviet Union successfully launched two successful uncrewed lunar missions -- Zond 5 and 6 -- and NASA's plans changed. The rest, as they say, is history. NASA

First Human Mission To The Moon

The mission was officially launched on December 21, 1968, through the Saturn V rocket. Although the astronauts involved in the mission were not able to land on the Moon, they were still able to complete a historical achievement for being the first humans to escape Earth's gravity and venture out into space. They were also the first humans to reach and orbit the Moon before returning to Earth.

Apollo 8 also provided the iconic "Earthrise" photo of Earth from the Moon's orbit. Taken by Anders, the photo shows a half-covered Earth and a portion of the lunar surface. According to the astronaut, despite being the first crewed mission to the Moon, the discoveries made during Apollo 8 gave him and his colleagues a new perspective of Earth.

Christmas Message From The Moon

Earthrise
"Earthrise" photo taken by astronaut Bill Anders. NASA/Bill Anders

The entire mission lasted for six days, which means that the astronauts spent Christmas in space. During the conversations with NASA's mission control, the astronauts were instructed to provide an appropriate message for the millions of people listening to them back on Earth. "We were told that on Christmas Eve we would have the largest audience that had ever listened to a human voice," Borman said as per NASA. "And the only instructions that we got from NASA was to do something appropriate."

After circling the Moon on Christmas Eve 10 times, the Apollo 8 mission prepared to return to Earth. Since the mission was the first of its kind, NASA anxiously waited for the astronauts' message from the Moon.

Establishing contact with the astronauts would also let Mission Control know that the Apollo 8's manoeuvre to leave the lunar orbit had worked. After waiting for several minutes for a response from Apollo 8, Mission Control finally heard back from one of the astronauts who provided an appropriate Christmas message. "Please be informed there is a Santa Claus," Lovell said.