As he studies the stars, the Rev. George Coyne finds the signature of God written in the universe.

The Jesuit priest, director of the Vatican Observatory, says Christian faith has nothing to fear from science. He will speak Thursday at Washington and Jefferson College on the relationship between faith and science.

"I meet, more times than I would like to, Catholics who sort of pray that scientists will not find out answers to certain questions so that they can continue to believe in God," Coyne said. "It's like God fills in the gaps of what they can't explain. But God is not explanation. God is love."

Coyne, 71, has been director of the Vatican Observatory for 26 years. As it happens, the Observatory is at the University of Arizona. Coyne was working there as an astronomer when his religious superior tapped him upon the unexpected death of his predecessor.

"I'm a Jesuit priest," he said. "I do what my superior tells me."

Vatican sponsorship of astronomy dates to 1582, when Pope Gregory XIII decided to reform the calendar, which was so far out of sync with the seasons that Easter was in danger of becoming a winter holiday. He asked Jesuit mathematicians and astronomers then teaching in Rome to devise an accurate calendar.

The resulting Gregorian calendar is still in use. "And it will live on, if we are still around, for 5,000 years before it has to be revised again," Coyne said.

The church's pursuit of astronomy continued despite the 1633 heresy trial of Galileo Galilei for maintaining that Earth revolved around the sun. In fact, 101 years before the 1992 apology of Pope John Paul II for the condemnation of Galileo, Pope Leo XIII established the Vatican Observatory.

"His motivation was to show the world that, far from there being a contrast between religious faith and scientific research, he wanted a group of religious priests doing scientific research as a sign of the agreement between the two," Coyne said.

"It wasn't founded in order to baptize extraterrestrials or to convert atheistic scientists."

The original 1891 observatory was established in the Vatican gardens. In 1935, after the lights of Rome became too bright to see many of the stars, the observatory moved to the papal summer residence of Castelgandolfo. But by 1980, that popular tourist region also was too well lit, and the observatory moved to a stargazers' desert paradise at the University of Arizona.

Since Galileo, the Catholic Church has not tried to treat the Bible as a text on science, Coyne said. Therefore, theories such as evolution did not present the same problems to Catholics as to some conservative Protestants.

"I don't think there are any real Catholic groups that are creationist," he said. "There are no Catholic institutions, as such, that would hold to such a strict, literal interpretation of Scripture."

The church doesn't judge scientific discoveries per se, but it can judge the morality of the methods that lead to discoveries and the uses to which discoveries are put, he said.

In past centuries, the church objected to scientists who robbed graves for cadavers, just as it objects to experimentation on embryos now.

"The search for truth by science and any other means is an inalienable right," Coyne said.

"To know what an ovum is and what the whole generative process of a human being is, is an inalienable right," he said. "But to destroy a fetus in order to know that is wrong. That method is wrong. The search for truth is not wrong.

"Science gets tainted sometimes because of the technological outcome. Scientists need to understand the thermonuclear process in order to understand stars. Because that's what happens in a star. But it's wrong to make use of it to build a nuclear bomb to kill people."

For Coyne, his vocation as a priest melds seamlessly with his vocation as a scientist.

"My scientific research is in many ways a prayer. Once I believe in God and try to understand the universe that I believe God created, it's a search for God himself."