A half-century ago, men from planet Earth stepped onto another world for the first time, uniting people around the globe in a way not seen before or since.

Hundreds of millions tuned in to radios or watched the grainy black-and-white images on TV as Apollo 11’s Neil Armstrong and Buzz Aldrin set foot on the moon on July 20, 1969, in one of humanity’s most glorious technological achievements.

In this July 20, 1969 photo made available by NASA, astronaut Buzz Aldrin, lunar module pilot, walks on the surface of the moon near the leg of the Lunar Module
In this July 20, 1969 photo made available by NASA, astronaut Buzz Aldrin, lunar module pilot, walks on the surface of the moon near the leg of the Lunar Module “Eagle” during the Apollo 11 extravehicular activity. (Neil Armstrong/NASA via AP)
FILE - In this July 16, 1969 file photo, from right, Neil Armstrong, Michael Collins and Buzz Aldrin walk to the van that will take the crew to the launchpad at Kennedy Space Center on Merritt Island, Florida. (AP Photo/File)
FILE – In this July 16, 1969 file photo, from right, Neil Armstrong, Michael Collins and Buzz Aldrin walk to the van that will take the crew to the launchpad at Kennedy Space Center on Merritt Island, Florida. (AP Photo/File)
In this July 16, 1969 photo made available by NASA, the 363-feet Saturn V rocket carrying the Apollo 11 crew, launches from Pad A, Launch Complex 39, at the Kennedy Space Center in Florida. (NASA via AP)
In this July 16, 1969 photo made available by NASA, the 363-feet Saturn V rocket carrying the Apollo 11 crew, launches from Pad A, Launch Complex 39, at the Kennedy Space Center in Florida. (NASA via AP)
FILE - In this July 16, 1969 file photo, people watch the Apollo 11 Saturn V rocket launch on multiple TV's at a Sears department store in White Plains, N.Y. (AP Photo/Ron Frehm, File)
FILE – In this July 16, 1969 file photo, people watch the Apollo 11 Saturn V rocket launch on multiple TV’s at a Sears department store in White Plains, N.Y. (AP Photo/Ron Frehm, File)
FILE - In this July 20, 1969 file photo, Andy Aldrin, 10, sits on a pile of cordwood in the backyard of his home in Houston while other members of his family listen to the reports of the progress of the Apollo II lunar module carrying his father, Col. Buzz Aldrin and fellow astronaut Neil Armstrong to a landing on the moon. (AP Photo)
FILE – In this July 20, 1969 file photo, Andy Aldrin, 10, sits on a pile of cordwood in the backyard of his home in Houston while other members of his family listen to the reports of the progress of the Apollo II lunar module carrying his father, Col. Buzz Aldrin and fellow astronaut Neil Armstrong to a landing on the moon. (AP Photo)
This July 16, 1969 photo made available by NASA shows the Earth as the Apollo 11 mission heads to the moon. (NASA via AP)
This July 16, 1969 photo made available by NASA shows the Earth as the Apollo 11 mission heads to the moon. (NASA via AP)
This July 20, 1969 photo made available by NASA shows Apollo 11 astronaut Buzz Aldrin in the Lunar Module cabin during the translunar coast. (Neil Armstrong/NASA via AP)
This July 20, 1969 photo made available by NASA shows Apollo 11 astronaut Buzz Aldrin in the Lunar Module cabin during the translunar coast. (Neil Armstrong/NASA via AP)
In this July 20, 1969 photo made available by NASA, the Apollo 11 Lunar Module undocks from the Command Module on its way to the surface of the moon. (Michael Collins/NASA via AP)
In this July 20, 1969 photo made available by NASA, the Apollo 11 Lunar Module undocks from the Command Module on its way to the surface of the moon. (Michael Collins/NASA via AP)
This July 20, 1969 photo made available by NASA shows crater Daedalus and Daedalus B, center left, during the Apollo 11 mission to reach the surface of the moon. (NASA via AP)
This July 20, 1969 photo made available by NASA shows crater Daedalus and Daedalus B, center left, during the Apollo 11 mission to reach the surface of the moon. (NASA via AP)
In this July 20, 1969 photo made available by NASA, astronaut Buzz Aldrin Jr. descends a ladder from the Lunar Module during the Apollo 11 mission. (Neil Armstrong/NASA via AP)
In this July 20, 1969 photo made available by NASA, astronaut Buzz Aldrin Jr. descends a ladder from the Lunar Module during the Apollo 11 mission. (Neil Armstrong/NASA via AP)
This July 20, 1969 photo made available by NASA shows Buzz Aldrins boot and bootprint during a test of the lunar soil during the Apollo 11 extravehicular activity. (Buzz Aldrin/NASA via AP)
This July 20, 1969 photo made available by NASA shows Buzz Aldrins boot and bootprint during a test of the lunar soil during the Apollo 11 extravehicular activity. (Buzz Aldrin/NASA via AP)
In this July 20, 1969 photo made available by NASA, astronaut Buzz Aldrin Jr. poses for a photograph beside the U.S. flag on the moon during the Apollo 11 mission. Aldrin and fellow astronaut Neil Armstrong were the first men to walk on the lunar surface with temperatures ranging from 243 degrees above to 279 degrees below zero. Astronaut Michael Collins flew the command module. (Neil Armstrong/NASA via AP)
In this July 20, 1969 photo made available by NASA, astronaut Buzz Aldrin Jr. poses for a photograph beside the U.S. flag on the moon during the Apollo 11 mission. Aldrin and fellow astronaut Neil Armstrong were the first men to walk on the lunar surface with temperatures ranging from 243 degrees above to 279 degrees below zero. Astronaut Michael Collins flew the command module. (Neil Armstrong/NASA via AP)
In this July 20, 1969 photo made available by NASA, astronaut Buzz Aldrin Jr. stands next to the Passive Seismic Experiment device on the surface of the the moon during the Apollo 11 mission. (Neil Armstrong/NASA via AP)
In this July 20, 1969 photo made available by NASA, astronaut Buzz Aldrin Jr. stands next to the Passive Seismic Experiment device on the surface of the the moon during the Apollo 11 mission. (Neil Armstrong/NASA via AP)
In this July 20, 1969 photo made available by NASA, flight controllers work in the Mission Operations Control Room in the Mission Control Center during the Apollo 11 lunar extravehicular activity. The television monitor shows astronauts Neil Armstrong and Buzz Aldrin on the surface of the moon. (NASA via AP)
In this July 20, 1969 photo made available by NASA, flight controllers work in the Mission Operations Control Room in the Mission Control Center during the Apollo 11 lunar extravehicular activity. The television monitor shows astronauts Neil Armstrong and Buzz Aldrin on the surface of the moon. (NASA via AP)
FILE - In this July 21, 1969 file photo, a family in Tokyo watches TV showing U.S. President Richard Nixon superimposed on a live broadcast of the Apollo 11 astronauts saluting from the moon. (AP Photo)
FILE – In this July 21, 1969 file photo, a family in Tokyo watches TV showing U.S. President Richard Nixon superimposed on a live broadcast of the Apollo 11 astronauts saluting from the moon. (AP Photo)
FILE - In this July 21, 1969 file photo, U.S. Air Force Sgt. Michael Chivaris, Clinton, Mass.; Army Spec. 4 Andrew Hutchins, Middlebury, Vt.; Air Force Sgt. John Whalin, Indianapolis, Ind.; and Army Spec. 4 Lloyd Newton, Roseburg, Ore., read a newspaper headlining the Apollo 11 moon landing, in downtown Saigon, Vietnam. (AP Photo/Hugh Van Es)
FILE – In this July 21, 1969 file photo, U.S. Air Force Sgt. Michael Chivaris, Clinton, Mass.; Army Spec. 4 Andrew Hutchins, Middlebury, Vt.; Air Force Sgt. John Whalin, Indianapolis, Ind.; and Army Spec. 4 Lloyd Newton, Roseburg, Ore., read a newspaper headlining the Apollo 11 moon landing, in downtown Saigon, Vietnam. (AP Photo/Hugh Van Es)
In this July 20, 1969 photo made available by NASA, Apollo 11 astronaut Buzz Aldrin works on a solar wind experiment device on the surface of the moon. (Neil Armstrong/NASA via AP)
In this July 20, 1969 photo made available by NASA, Apollo 11 astronaut Buzz Aldrin works on a solar wind experiment device on the surface of the moon. (Neil Armstrong/NASA via AP)
In this July 21, 1969 photo made available by NASA, astronaut Neil Armstrong, Apollo 11 commander, sits inside the Lunar Module after he and Buzz Aldrin completed their extravehicular activity on the surface of the moon. (Buzz Aldrin/NASA via AP)
In this July 21, 1969 photo made available by NASA, astronaut Neil Armstrong, Apollo 11 commander, sits inside the Lunar Module after he and Buzz Aldrin completed their extravehicular activity on the surface of the moon. (Buzz Aldrin/NASA via AP)
This July 21, 1969 photo made available by NASA shows Tranquility Base and the U.S. flag from a window on the Lunar Module as Neil Armstrong and Buzz Aldrin prepare for liftoff from the surface of the moon. (NASA via AP)
This July 21, 1969 photo made available by NASA shows Tranquility Base and the U.S. flag from a window on the Lunar Module as Neil Armstrong and Buzz Aldrin prepare for liftoff from the surface of the moon. (NASA via AP)
In this July 21, 1969 photo made available by NASA, the Apollo 11 Lunar Module ascent stage, carrying astronauts Neil Armstrong and Buzz Aldrin, approaches the Command and Service Modules for docking in lunar orbit. Astronaut Michael Collins remained with the CSM in lunar orbit while the other two crewmen explored the moon's surface. In the background the Earth rises above the lunar horizon. (Michael Collins/NASA via AP)
In this July 21, 1969 photo made available by NASA, the Apollo 11 Lunar Module ascent stage, carrying astronauts Neil Armstrong and Buzz Aldrin, approaches the Command and Service Modules for docking in lunar orbit. Astronaut Michael Collins remained with the CSM in lunar orbit while the other two crewmen explored the moon’s surface. In the background the Earth rises above the lunar horizon. (Michael Collins/NASA via AP)
In this July 24, 1969 photo from the U.S. Navy, Navy UDT swimmer Clancy Hatleberg prepares to jump from a helicopter into the water next to the Apollo 11 capsule after it splashed down in the Pacific Ocean, to assist the astronauts into the raft at right. (Milt Putnam/U.S. Navy via AP)
In this July 24, 1969 photo from the U.S. Navy, Navy UDT swimmer Clancy Hatleberg prepares to jump from a helicopter into the water next to the Apollo 11 capsule after it splashed down in the Pacific Ocean, to assist the astronauts into the raft at right. (Milt Putnam/U.S. Navy via AP)
FILE - In this July 24, 1969 file photo, President Richard Nixon gives an
FILE – In this July 24, 1969 file photo, President Richard Nixon gives an “OK” sign as he greets Apollo 11 astronauts Neil Armstrong, Michael Collins, and Buzz Aldrin in a quarantine van aboard the USS Hornet after splashdown and recovery in the Pacific Ocean. (AP Photo)
FILE - In this Aug. 13, 1969 file photo, people line 42nd Street in New York to cheer Apollo 11 astronauts, in lead car from left, Buzz Aldrin, Michael Collins and Neil Armstrong, traveling east on 42nd street, towards the United Nations. (AP Photo/File)
FILE – In this Aug. 13, 1969 file photo, people line 42nd Street in New York to cheer Apollo 11 astronauts, in lead car from left, Buzz Aldrin, Michael Collins and Neil Armstrong, traveling east on 42nd street, towards the United Nations. (AP Photo/File)
This March 30, 1969 photo made available by NASA shows the crew of the Apollo 11, from left, Neil Armstrong, commander; Michael Collins, module pilot; Edwin E.
This March 30, 1969 photo made available by NASA shows the crew of the Apollo 11, from left, Neil Armstrong, commander; Michael Collins, module pilot; Edwin E. “Buzz” Aldrin, lunar module pilot. Apollo 11 was the first manned mission to the surface of the moon. (NASA via AP)
In this July 20, 2009 file photo, Apollo 11 astronauts, from left, Buzz Aldrin, Michael Collins and Neil Armstrong stand in the Oval Office at the White House in Washington, on the 40th anniversary of the mission's moon landing. (AP Photo/Alex Brandon)
In this July 20, 2009 file photo, Apollo 11 astronauts, from left, Buzz Aldrin, Michael Collins and Neil Armstrong stand in the Oval Office at the White House in Washington, on the 40th anniversary of the mission’s moon landing. (AP Photo/Alex Brandon)