Celebrate Space Exploration Day by looking up at the sky on July 20 and reflecting on human achievements in space and all that’s to come.

On July 20, 1969, U.S. astronauts Neil Armstrong and Buzz Aldrin became the first humans to set foot on the moon’s surface. Fellow astronaut Michael Collins flew the command module.

Here is a look back at the first moon landing:

Three men in spacesuits posing in front of image of moon (NASA/AP Images)

All of the  Apollo 11 crew had flown at least one space mission. Pictured from left: Neil Armstrong, commander; Michael Collins, module pilot; Edwin E. “Buzz” Aldrin, lunar module pilot, on March 30, 1969. (NASA/AP Images)

Men in spacesuits walking toward vehicle and waving to men watching them (© AP Images)

Neil Armstrong, waving in front, heads for the van that will take the crew to the rocket for launch to the moon at Kennedy Space Center in Merritt Island, Florida, on July 16, 1969. (© AP Images)

Rocket with smoke and flames taking off from launch pad (NASA/AP Images)

The 363-foot Saturn V rocket carrying the Apollo 11 crew launches July 16, 1969, from Pad A, Launch Complex 39, at the Kennedy Space Center in Florida. (NASA/AP Images)

Photo of players lined up on baseball field (© Bill Ingraham/AP Images) next to photo of crowd watching TV through storefront window (© Edwin Reichert/AP Images)Left: The Chicago Cubs (foreground), Philadelphia Phillies and fans in attendance bow their heads in a moment of silent prayer in Philadelphia on July 20, 1969, hoping for the safe voyage of the Apollo 11 mission to the moon. (© Bill Ingraham/AP Images)

Right: Berliners stand in front of a TV shop and watch the Apollo 11 space mission on television July 16, 1969, in Germany. (© Edwin Reichert/AP Images)

Blurry image of Neil Armstrong walking on surface of moon (NASA/AP Images)

“That’s one small step for man, one giant leap for mankind,” said astronaut Neil Armstrong as he became the first human to set foot on the moon, as shown in the image from television. (NASA/AP Photo)

Photo of foot on surface of moon (Buzz Aldrin/NASA/AP Images) next to photo of spacesuited man on surface of moon (Neil Armstrong/NASA/AP Images)

Left: Buzz Aldrin leaves a footprint on the moon’s Sea of Tranquility. Photographs of the footprints were actually part of a planned experiment by Aldrin to study the nature of the lunar dust and the effects of pressure on the surface. (Buzz Aldrin/NASA/AP Images)

Right: Neil Armstrong took this picture of Buzz Aldrin, which shows a reflection of Armstrong and the Lunar Module in Aldrin’s visor. (Neil Armstrong/NASA/AP Images)

Photo of Earthrise over the lunar horizon (NASA) next to photo of the lunar module in space (NASA/AP Images)

Left: This photo of Earthrise over the lunar horizon, taken July 20, 1969, from the orbiting command module, is one of the most famous images captured by the space program, although even the astronauts cannot remember who actually took the photo. (NASA)

Right: After lifting off from the lunar surface, the lunar module made its rendezvous with the command module. The Eagle docked with Columbia, and the lunar samples were brought aboard. (NASA/AP Images)

Photo of lunar module floating in ocean (NASA) next to photo of men in room with computers and large, elevated screen waving American flags (NASA/AP Images)

Left: The three astronauts and a Navy frogman, all wearing biological isolation garments, awaiting helicopter pickup and transport to the USS Hornet after the lunar module splashed down about 1,504 kilometers southwest of Hawaii at 16:50 UTC on July 24, 1969. They stayed in quarantine for three weeks. (NASA)

Right: NASA flight controllers at the Mission Operations Control Room in the Mission Control Center at the Manned Spacecraft Center in Houston celebrate the successful conclusion of the Apollo 11 lunar landing mission. (NASA/AP Images)