It was the morning of October 13, 1917, and an immense crowd was making its way to the Cova da Iria. People came from all over Portugal. Some had walked for days. Wagons, carriages, automobiles, bicycles, and thousands on foot, all heading for a simple field where three children said that Our Lady appeared.

But there was a problem: it was raining without pause, a cold October rain. The field had turned to mud, and everyone was soaked through. Journalists who believed in nothing at all were there too, laughing under their umbrellas, ready to write that the whole thing was a hoax. The sky was covered with heavy gray clouds, without a single ray of sun. How could there be a miracle in weather like that?

There were about seventy thousand people. Elegant ladies with their umbrellas, poor farmers, priests, curious onlookers, believers and unbelievers, journalists and photographers. All of them wet, all of them in the mud, all of them waiting.

At midday, Lucia, Francisco, and Jacinta arrived, small and humble, making their way through that enormous crowd.

"Close your umbrellas," Lucia asked. "Our Lady is coming."

And a curious thing happened: seventy thousand people obeyed. They closed their umbrellas in the pouring rain and got wetter still. There was something in that little girl's voice that made people believe.

Then came the flash of light, and Our Lady appeared over the holm oak. Only the three children could see her.

"What do you want of me?" Lucia asked.

"I want to tell you to have a chapel built here in my honor," Our Lady answered. "Continue always to pray the Rosary every day. The war is going to end, and the soldiers will soon return to their homes."

"I have many things to ask," said Lucia. "Cures for the sick, conversions..."

"Some yes, others no," Our Lady replied. "They must amend their lives and ask forgiveness for their sins."

And, growing very serious, she added:

"Do not offend the Lord our God any more, for He is already much offended."

Then Our Lady opened her hands, and the light streaming from them rose up and seemed to reflect off the sun itself.

"Look at the sun!" Lucia cried to the crowd.

And it happened. The rain stopped all at once, the clouds parted, and the sun came out. But it was not the everyday sun. It was like a silver disc, and people could look at it without hurting their eyes. And then the sun began to dance.

The witnesses later told what they had seen. The sun began to spin like a wheel of fire, faster and faster, throwing out rays of colored light in every direction: red, blue, yellow, green, purple. The whole landscape kept changing color. The people, the trees, the ground — everything was bathed in that light no one could explain.

"A miracle! A miracle!" thousands of voices cried.

People knelt in the mud, weeping. People who never prayed began to pray. Sinners asked God's forgiveness out loud.

But then something frightening happened. The sun seemed to break loose from the sky and began to come down, as if it were going to fall upon the earth.

"The sun is falling!" people screamed in terror. "It's the end of the world!"

Mothers clutched their children. Grown men wept. The whole crowd begged for mercy, because the sun seemed bigger and closer with every moment.

And then, when the fear was at its greatest, the sun stopped. It climbed slowly back to its place in the sky and stood still, as it always had. The miracle had lasted about twelve minutes.

The people rose slowly to their feet, trembling, crying, but alive. And then they noticed something else astonishing: everyone's clothes were completely dry. Minutes before, they had been drenched with rain and covered in mud; now they were dry and clean, as if it had never rained at all. Even the ground of the field was dry.

The journalists who had come to mock were left without words. Avelino de Almeida, a reporter for the biggest anti-Catholic newspaper in Portugal, wrote that before the astonished eyes of that crowd, the sun trembled and made sudden movements never seen before — the sun "danced," as the country people said. Another journalist wrote that the sun turned pale like a disc of dull silver, spinning upon itself. And a professor from the University of Coimbra, Dr. Jose Almeida Garrett, described in a careful report how the sun at times seemed to loosen itself from the sky and rush toward the earth. Even those who doubted everything had to admit that something far out of the ordinary had happened there.

Meanwhile, the three children had seen something more. When Our Lady opened her hands, they saw, beside the sun, three visions. First, Saint Joseph with the Child Jesus in his arms, both of them blessing the world. Then Jesus grown, blessing the people, with Our Lady of Sorrows at his side, dressed in purple. And finally, Our Lady alone, radiant, as Our Lady of Mount Carmel. Only the children saw these visions. But the sun — the whole crowd saw the sun dance.

When it was all over, the field was in an uproar. People laughed and cried at the same time, embraced one another, and told each other what they had seen. A man who had gone there to mock fell to his knees and asked God's forgiveness on the spot. Cures and very many conversions are told of that day. Thousands of people went home different from how they had arrived.

In the days that followed, the newspapers reported the solar phenomenon of Fatima, and even those hostile to religion had to admit that something inexplicable had taken place. Some tried to explain it: perhaps it was the crowd's imagination. But how could seventy thousand people imagine the same thing at the same time? Perhaps it was a trick of the weather. But what weather makes the sun seem to fall, and dries the clothes of seventy thousand people and a whole muddy field in an instant? For those who were there, there was no doubt. It was a miracle. God had spoken.

And why would God work such a spectacular miracle? To confirm the message. Our Lady had entrusted important requests to the children, but many people doubted, saying they were only children making up stories. So God did something no one could deny, before seventy thousand witnesses: believers, unbelievers, journalists, photographers. Our Lady's message was true, and it needed to be heard: pray the Rosary every day, do penance, turn your heart back to God.

The Miracle of the Sun is considered the greatest public miracle of modern times. Never had so many people witnessed such an event together, so clearly. The Catholic Church investigated everything with great care, over many years: it heard witnesses, examined accounts, and consulted scholars. In 1930, the Bishop of Leiria officially declared that the apparitions of Our Lady at Fatima were worthy of belief, and that the faithful were free to believe in them. Fatima was approved by the Church.

Today, the Shrine of Fatima is one of the most visited places of pilgrimage in the world. Millions of people come every year, from every country. Several Popes have been there and have consecrated the world to the Immaculate Heart of Mary. Saint John Paul II had a special devotion to Fatima: when he was shot in 1981 — on the thirteenth of May, the anniversary of the first apparition — he credited Our Lady of Fatima with saving his life. The bullet that nearly killed him was placed in the crown of the statue of Our Lady of Fatima.

The Miracle of the Sun has remained in the world's memory as a sign that God exists and cares about us, that Our Lady is our Mother who comes to warn and help us, and that miracles did not happen only in Bible times. The promise made in July was kept in October, on the appointed day and at the appointed hour, before everyone.

"I am the Lady of the Rosary," she said that day. "Continue always to pray the Rosary every day."