Ten Apollo 11 facts

1. Buzz Aldrin had hoped to be the first man to walk on the moon. However, the honour went to Neil Armstrong for reasons of both protocol and practicality – he was the mission commander, and also the way the hatch of the lunar module opened meant that Armstrong had to get out first.

2. Neil Armstrong was a civilian, and the highest paid astronaut, with a salary reported at the time as being over 27,000 dollars. Buzz Aldrin and Michael Collins were military.

3. Armstrong had nearly been killed on the Gemini 8 space mission in 1966 when a thruster stuck open, sending the spacecraft rotating crazily. He managed to regain control but the mission was abandoned.

4. As the lunar module came in to land, alarms went off because the computers were overloaded. After assessment, the alarms were ignored.

5. The lunar module was down to only about 20 seconds of fuel left after Armstrong had manoeuvred to find a safe site.

6. Nobody could be certain what would happen when the lunar module touched down. One astronomer, Thomas Gold, had predicted that the lander would be completely swallowed up by a surface of powdery moon dust.

7. As they got out, Armstrong and Aldrin accidentally bumped into, and broke off, the switch to arm the rocket engine to blast off again. Aldrin fixed it by shoving a pen into the broken switch.

8. The American flag they planted on the moon was stiffened with wire so that it would "wave." It was blown over when the lunar module blasted off.

9. On their return to Earth the three Apollo astronauts were kept isolated as a precaution against "moon germs."

10. The lunar footprints of Armstrong and Aldrin may last for 100 million years.