In 1531, in Mexico City, Mexico, our Lady appeared to 57-year-old widower, Juan Diego as he was on his way to attend Mass. Juan Diego was an Aztec Indian and a convert to Christianity.
Our Blessed Mother revealed her identity to Juan Diego and told him she wanted him to inform the bishop of the diocese that she would like a chapel built in the place she was standing so she could have a place in which she could lead people to her Son. Juan agreed and met with the bishop, however was quickly dismissed.
Our Blessed Mother appeared to Juan a second time to see if he had made any progress with her request. Juan explained that he was quickly dismissed and suggested to our Lady that she find a more prominent member of the village, someone whom the bishop would be more likely to listen to. Our Blessed Mother insisted that Juan go back to the bishop once more, which he did. This time, the bishop told Juan he would take the request seriously if Our Lady would give a sign.
In an attempt to avoid Our Lady, Juan took a different route as he walked to attend Mass, however, Our Lady once again appeared to him to question him regarding her request. Juan explained about the bishop's request for a sign.
Our Blessed Mother than directed Juan to pick some roses on a hill nearby and bring them to her. The roses that Our Lady requested did not normally grow in the season in which she appeared to Juan Diego. Nonetheless, Juan brought a bunch of roses back to Our Lady. She then directed him to give her his tilma (cloak). Our Blessed gently laid the tilma on the ground, wrapped the roses in the tilma, and gave it back to Juan directing him to take it and give it to the bishop.
Juan promptly delivered his tilma to the bishop, and upon opening it in the bishop's presence, the roses fell out and the two gazed in amazement upon the most beautiful image of Our Lady which covered the entire tilma. The bishop was convinced of the miracle and built the chapel. Within approximately eight years of the building of the chapel, there were nearly 7 million converts to Christianity in what was then a pagan society.
Recently scientists have discovered some truly amazing facts about the tilma and its image that defy nature and all scientific explanation. Here are a few:
The plant fibers tilmas are made of wear out after fifty years, but the Tilma of Our Lady has endured 480 years. For 116 years it was left unprotected from smoke, dust, heat, humidity, and continual contact with hands and other objects. Not even the accident in 1791, when muriatic acid fell on the Tilma, nor the terrorist attack in 1921, when a bomb was placed in front of her in a flower vase, have been able to destroy the Tilma of Guadalupe.
NASA has stated that the image’s colors are not made from any material found on Earth. A laser that scanned the image even found that the colors float three tenths of a millimeter in front of the Tilma surface, without touching it.
Microscopic analysis of the pupils of Our Lady of Guadalupe reveals what she must have seen in the instant her image appeared. She is surrounded by thirteen people. One of these is clearly identified as Bishop Juan de Zumárraga. Zooming in even more, to the point of examining the Bishop’s pupils, reveals the spectacle he saw: Juan Diego opening his garment in front of him. The Virgin exhibits qualities of a living person, too. Her eyes contract and dilate in response to light and darkness. The temperature of the Tilma remains stable at 98.6 degrees. A stethoscope has even measured the heartbeats of a baby in her womb.
The aforementioned facts were obtained from the following source - http://www.catholic.net/index.php?option=dedestaca&id=6003.