The supplies stored by the Indians were very few, so they looked forward to the arrival of the next moon for the harvest, feed their people and re-cultivate.
That would happen the next night, but the dawn of that day was not as usual, there was a lot of humidity, the sky began to turn red, the desperate Indians panicked, they began to pray and implore their gods to help them, they believed that it would rain blood and their crops and all their work would be ruined.
After a while, the sky gradually cleared and returned to normal, the happy natives celebrated the miracle that the gods had granted them, offering them offerings for having heard their pleas.
They would never know what really happened, for that time there was no science, only their beliefs, the sun's rays almost reaching the surface in parallel, they cross a layer of atmospheric gases, filtering radiation, letting only red light pass, a simple natural phenomenon.