In Spring of 1916, three Portuguese children reported that they saw visions of an angel. They were shepherds under the age of ten. Then, in May of 1917, they said the Virgin Mary appeared to them. She told them prayer was needed for the world to know peace. Prayer would bring an end to the Great War, World War I. The children began telling others that Mary would show herself and perform a miracle to bring people to faith on October 13th.1
When the day came, the crowd was massive. Some estimate between 30,000 and 100,000 people. Members of the crowd say it had been raining, but then the sun emerged, looking opaque. Sparkling lights streamed across the sky – scarlet, purple, blue, all colors of the rainbow. To some, it seemed that the sun was about to crash into the earth. To others, it just whirled and turned. Some saw nothing at all.2 What really happened that day?
[1] https://en.wikipedia.org/wiki/Miracle_of_the_Sun
[2] https://en.wikipedia.org/wiki/Miracle_of_the_Sun