On July 20, 1969, Neil Armstrong and Buzz Aldrin landed on the moon.
Since then, the United States has put men on the moon six more times.
Yet conspiracy theorists insist none of this ever happened, believing instead that the lunar landings were nothing more than an expensive plot involving elaborate film sets executed under the creative direction of filmmaker Stanley Kubrick.
A full 11 percent of Americans either have their doubts the lunar landings actually happened, according to a 1999 Gallup poll, as reported by Time.
Forget the moon, if you believe the news, a human mission to Mars is no longer a sci-fi fantasy. But what problems would we need to overcome? And should we even try?