Final answer:
The feather and coin experiment on the Moon showed that without air resistance, objects of different masses fall at the same rate, confirming Galileo's theory.
Step-by-step explanation:
The main conclusion of the feather and coin experiment is that in the absence of air resistance, objects with different masses fall at the same rate due to gravity. This was famously demonstrated on the Moon by Apollo 15 astronaut David Scott in 1971. Without an atmosphere to create air resistance, the feather and hammer he dropped landed on the lunar surface at the same time. This experiment confirms Galileo's theory of falling objects and illustrates the principle that in a vacuum, all objects accelerate at the same rate regardless of their mass.