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Lunar knowledge

The List: 7 facts about the moon

Apollo 11 astronauts Neil Armstrong, left, and Buzz Aldrin, right, shown with Michael Collins, are among the 12 humans who have walked on the moon. Image: NASA

To help mark the release of the 1969: First Moon Landing stamps this week, here are seven facts about Earth’s closest neighbor.

1. The moon is not a dairy product. Despite countless children’s stories to the contrary, the moon is not made of cheese. Rocks that have been brought back from NASA’s Apollo missions show that the elements present in the moon’s surface are oxygen, silicon, iron, magnesium, calcium, aluminum, manganese and titanium, among others, but not cheese.

2. The moon has two sides. Spherical objects don’t have sides. However, the moon is in synchronous rotation with the Earth, which means the same portion of the moon always faces us. This is called the near side. And the other side — the one we don’t see — is the far side.

3. We don’t know how the moon was formed. The leading theory is that a Mars-size object collided with the Earth approximately 4.5 billion years ago. The resulting impact blasted material from the Earth into orbit, eventually forming the moon.

4. The moon is thought to be approximately 4.51 billion years old. While that’s plenty old, the Earth is a little older and the solar system is about 4.6 billion years old.

5. More than 600 million people worldwide watched the 1969 moon landing. This is the estimated size of the television audience that tuned in to see Apollo 11 astronauts Neil Armstrong and Buzz Aldrin walk on the moon. The audience in the United States was estimated to be between 125 million and 150 million, despite the fact that the landing occurred at 10:56 p.m. on a Sunday.

6. Only 12 humans have walked on the moon. In chronological order, they are Armstrong, Aldrin, Pete Conrad, Alan Bean, Alan Shepard, Edgar Mitchell, David Scott, James Irwin, John Young, Charles Duke, Gene Cernan and Harrison Schmitt. Only four are still living: Aldrin, Scott, Duke and Schmitt.

7. At least one human has called the moon. After Apollo 11 landed on the moon, Armstrong and Aldrin took a phone call from President Richard M. Nixon. “This certainly has to be the most historic phone call ever made from the White House,” he said.

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