Secchi was born in
Reggio Emilia, where he studied at the Jesuit
gymnasium. At the age of 16, he entered the
Jesuit Order in
Rome. He continued his studies at the Roman College, and demonstrated great scientific ability. In 1839, he was appointed tutor of
physics at the College. In 1841, he became Professor of Physics at the Jesuit College in
Loreto. In 1844, he began
theological studies in Rome, and was
ordained a priest on 12 September 1847. In 1848, due to the
Roman Revolution, the Jesuits had to leave Rome. Fr. Secchi spent the next two years in the
United Kingdom at
Stonyhurst College, and the
United States, where he taught for a time at
Georgetown University in
Washington, DC. He also took his doctoral examination in theology there.
During his stay in America, he met Commander
Matthew Fontaine Maury, the first Director of the
United States Naval Observatory in Washington. He studied with Maury and corresponded with him for many years.
He returned to Rome in 1850. On the recommendation of his late colleague
Francesco de Vico, he became head of the Observatory of the College at age 32. In 1853, under his direction, the crumbling Observatory was relocated to a new facility on top of the
Sant'Ignazio Church (the chapel of the College). Secchi served as Director until his death.
His position was challenged after 1870, when the remnant of the
Papal States around Rome
was taken over by the
Kingdom of Italy. In 1873, the College was declared property of the Italian government. When the government moved to take over the Observatory as well, Secchi protested vigorously, and threatened to leave the Observatory for one of several positions offered to him by foreign observatories. He was offered important scientific positions and political dignities by the government, but refused to pledge allegiance to the Kingdom in place of the Pope. The royal government did not dare to interfere with him, and he continued as Director.
He died in 1878 at age 59, in Rome.