The Vatican has since washed its hands of the responsibility of telling the world the 3rd Secret Of Fatima. They've convinced everyone that the attempt on Pope John Paul's life was, in fact, the final secret. However, anyone interested in what actually happened at Fatima, Portugal can probably surmise what the 'true' 3rd secret was.
A young woman appears to three children. She's a child herself. Described as somewhere between 12-15 years of age. When she speaks her mouth does not move. She is more of a hologram than an actual person. She holds a globe or sphere in her hands. She wears a cloak. She looks nothing like the classic Marian depiction we've come to see on Franklin Mint statues, etc.
Then there is the Miracle of the Sun. Essentially, a UFO sighting. A metal/silver disc covered in lights, acting erratic...
If you ask me; the fact that the Vatican is interested in Extraterrestrial life and coupled with all Marian apparitions that have become historical events...it seems the 3rd Secret of Fatima is this:
WE ARE NOT ALONE.