When man first harnessed fire, no one recorded it. When the Wright Brothers showed man could fly, only a handful of people witnessed it. But when Neil Armstrong took that first small step on the moon in July 1969, an entire globe watched in grainy black-and-white from a quarter-million miles away.
We saw it. We were part of it. He took that "giant leap for mankind" for us.
Although more than half of the world's population wasn't alive then, it was an event that changed and expanded the globe.
"It's a human achievement that will be remembered forever," said John Logsdon, professor emeritus of space policy at George Washington University.
Those first steps were beamed to nearly every country around the world, thanks to a recently launched satellite. It was truly the first global mass media event, Mr. Logsdon said. An estimated 600 million people -- 1 out of every 5 on the planet -- watched.
The two historical events likely to be long remembered from the 20th century are the moon landing and the first atomic bomb, said Smithsonian Institution space curator Roger Launius.
"There is no way to overestimate that significance in human history and he is forever linked to that," Mr. Launius said of Mr. Armstrong, who died Saturday at age 82.
Just as the voyage of Christopher Columbus split historic eras 500 years ago, so will Mr. Armstrong and Apollo 11, said Rice University historian Douglas G. Brinkley, a specialist in 20th century history.
"We may be living in the age of Armstrong," said Mr. Brinkley, who conducted oral histories for NASA, including sessions with Mr. Armstrong.
Since that day, there's been a common phrase: "If we can send a man to the moon, why can't we ?" with the blank filled with a task that seems far less difficult.
Mr. Armstrong's small step was that leap in confidence telling the world, "If we can do this, we can do anything," said Howard McCurdy, a professor of space and public policy at American University and author of the book "Space and the American Imagination."
"He took something that 20 years earlier was pure fantasy and turned it into reality and if we could do that for space we could do it for anything," Mr. McCurdy said.
The Apollo 11 moon landing was the finish line in a decade-long space race started by the Soviet Union. And so the first steps on the moon coming from an American civilian had many meanings. Getting there first showed American technological superiority, but Mr. Armstrong mentioned mankind -- not Americans -- demonstrating that this was a moment for the people of Earth, Mr. McCurdy said.
Mr. Armstrong and Buzz Aldrin left a plaque on the moon that read: "Here men from the planet Earth first set foot upon the moon. July 1969 A.D. We came in peace for all mankind."
For all mankind. And that's how the world took it.
Reported the Swahili-language newspaper Nguromo of Dar at the time: "The success for America [is] success for every living man"
If that wasn't enough, Mr. Armstrong and Mr. Aldrin also left a patch to commemorate NASA astronauts and Soviet cosmonauts who had died in pursuit of space.
It's permeated into culture, probably because in some ways that walk touched something that has been hard-wired into humanity: the need to explore. For 25,000 years, humans have been migrating and pushing into new places.
Mr. Armstrong took it to new heights.