Mary appeared to three children in Portugal at the beginning of the twentieth century. She made several predictions, all of which have come true. She called the world to repentance to avoid war. You can find out more about the Marian apparitions at Fatima here
This statue travels the world for those who can't go to Portugal. By the way Catholics don't worship either Mary or the statue. The statue helps us concentrate our thoughts on Mary, just as a photo of our children on our desk at work helps us think of them. The Church teaches that Mary by herself can do nothing. It is her intersession on our behalf with Jesus that we seek. Just as we ask our living friends to pray for us so to can we ask our friends who are already with God to pray for us.

I posted this today because today is the Feast of the Solemnity of Mary Mother of God where the Church recognizes that since Jesus is both fully human and Divine Mary can rightfully be called the Mother of God. You can find out more about Catholic beliefs here

The photo was taken at Our Lady of Peace Church in Santa Clara CA. i've got more photos of the shrine here.