Petition sent by the astronomer Nicolaus Copernicus to pope Paul III is showed at the exhibition 'Lux in Arcana, the Vatican Secret Archives reveals itself' in Rome , Italy on February 29, 2012. Hundred original and priceless documents selected among the treasures preserved and cherished by the Vatican Secret Archives for centuries go on show for first time. It will be the first and possibly the only time in history that they leave the confines of the Vatican City walls. And they will do so in order to be housed and displayed in the beautiful halls of the Capitoline Museums in Rome. One hundred original and priceless documents selected among the treasures preserved and cherished by the Vatican Secret Archives for centuries. The exhibition which is conceived for the 4th Centenary of the foundation of the Vatican Secret Archives aims at explaining and describing what the Pope?s archives are and how they work and, at the same time, at making the invisible visible, thus allowing access to some of the marvels enshrined in the Vatican Secret Archives? 85 linear kilometers of shelving; records of an extraordinary historical value, covering a time-span that stretches from the 8th to the 20th century.The name, Lux in arcana, conveys the exhibition?s main objective: the light piercing through the Archive?s innermost depths enlightens a reality which precludes a superficial knowledge and is only enjoyable by means of direct and concrete contact with the sources from the Archive, that opens the doors to the discovery of often unpublished history recounted in documents. The 100 documents, chosen among manuscript codices, parchments, strings and registers, will remain at the Capitoline Museums for nearly seven months, from 1st March till September 2012. An extremely prestigious location, chosen to host this memorable event since it underlines the profound bond existing between the city of Rome and the Papacy since medieval times; the origins of both institutions involved in the e