The Pope's chief astronomer says that life on Mars cannot be ruled out.
Writing in the Vatican newspaper, the astronomer, Father Gabriel Funes, said intelligent beings created by God could exist in outer space.
Father Funes, director of the Vatican Observatory near Rome, is a respected scientist who collaborates with universities around the world.
The search for forms of extraterrestrial life, he says, does not contradict belief in God.
The official Vatican newspaper headlines his article 'Aliens Are My Brother'.