The questions of life's origins and of whether life exists elsewhere in the universe are very suitable and deserve serious consideration according to director of the Vatican Observatory, Fr Jose Gabriel Funes.
He was speaking after dozens of scientists gathered at a Vatican-sponsored meeting to study the possibility of alien life in the universe and its implication for the Catholic Church.
The study was part of events marking the UN-designated International Year of Astronomy.
Fr Funes presented the results of the five-day conference that gathered astronomers, physicists, biologists and other experts to discuss the budding field of astrobiology — the study of the origin of life and its existence elsewhere in the cosmos.
The Jesuit priest said the possibility of alien life raises "many philosophical and theological implications" but added that the gathering was mainly focused on the scientific perspective and how different disciplines can be used to explore the issue.
At a press conference following the study week, Chris Impey, head of the Steward Observatory and the University of Arizona's department of astronomy, said that if finding extraterrestrial life is like "a detective chase, a crime to be solved, we're getting very close to the answer".
Impey was one of the 30 high-level scientists attending the study week.
Fr Funes said that even though they looked exclusively at scientific evidence and theories, it was "very important that the Church is involved in this type of research" of looking at life in the cosmos.
He quoted Cardinal Giovanni Lajolo, president of the commission governing Vatican City, as telling participants that "truth from research cannot make us afraid; what is to be feared is error."
Science opens up the human mind to new knowledge and contributes toward the fulfilment of humankind, the cardinal said, according to Fr Funes.
When asked whether God would have to be incarnated elsewhere if there were intelligent life on another planet, Fr Funes recalled the parable of the lost sheep.
God's incarnation in Jesus Christ was a singular and "unique event not only in human history but in the history of the universe and the cosmos," he said.
The existence of evil and original sin on Earth meant God, the good shepherd, had to leave behind his entire flock to go get his one lost sheep, he said.
"Humanity would be this lost sheep and in order to find this lost sheep (God) became man in Jesus," according to Fr Funes.
Chris Impey said that whether there is extraterrestrial life or not, either scenario "is staggering." He added, "If the universe is abundant in life there is companionship in our future".
But if space exploration after several decades turns up nothing, then it will help remind people that "this planet is rather special and so with that will come an extra obligation even if we didn't already feel it to care of this place and this special thing that happened here."
Jonathan Lunine, professor of planetary science and physics at the University of Arizona, said three or four worlds within the solar system also have conditions where life may be found.
He said more research into how the Earth and earthly life evolved is helpful in understanding what habitable worlds may look like.
One key mystery that lacks a complete scientific explanation is why it took so long -- 1 billion to 2 billion years -- for complex cells to appear and then another 1 billion to 2 billion years for complex animal life to emerge, Lunine said.
Discoveries of life in very inhospitable conditions on Earth, such as rock-eating microbes living deep beneath the ocean floor, show that different life forms may exist on other worlds, according to Fr Funes.
Athena Coustenis, a planetary scientist at the Paris-Meudon Observatory in France, said astronomers once thought almost all of the satellites circling Saturn "were dead icy worlds."
But space missions there have shown all of Saturn's major moons are actually "wonderful active worlds," she said, with one, called Enceladus, "spitting out its guts with water, liquid water, water vapour, organics and ammonia in these huge plumes extending more than 250 miles into space."
The evidence suggests that the jets originate in an underground ocean of liquid water, indicating that all the ingredients for life seem to be on Enceladus as well, she said.
