How fast can humans run?

Source: NASA

After 40 years in the dark, this question was finally answered. Experiments to see how fast a human can run on the moon has taken place. Taking place on NASA's DC-9 aircraft. An aircraft capable of reducing its internal gravity to the match the moon's while in the swooping motion. There were eight participants, three being astronauts. Each astronaut was asked to run for 20 seconds long in the artificial lunar gravity.

Source: NASA

The theoretical average calculated by NASA was 1.8 miles per hour (2.89 km), was a dramatic difference to the average on Earth being 4.5 miles per hour (7.24 km). After the experiments, the results was an average of 3 miles per hour (5 km), a much closer calculation. The theory revolving around why their theoretical calculation is the boost created by the counter-swinging motion of the participants' arms and legs.