Here's why we know this is true:

* Multiple Missions: There were six successful Apollo missions that landed astronauts on the Moon between 1969 and 1972.

* Physical Evidence: We have tons of physical evidence from these missions, including:

* Moon rocks: Brought back to Earth and analyzed by scientists worldwide.

* Lunar surface photographs and videos: Taken by the astronauts, showing the Moon's landscape and their activities.

* Laser reflectors: Placed on the Moon by the Apollo astronauts, used to precisely measure the distance between Earth and the Moon.

* Independent Confirmation: Data from independent sources, like telescopes and orbiting spacecraft, have corroborated the Apollo missions' findings.

* Eyewitness Accounts: Multiple astronauts have provided detailed and consistent accounts of their experiences on the Moon.

While some conspiracy theories exist, the overwhelming evidence points to the undeniable fact that humans have walked on the Moon.