TUCSON, Ariz. (AP) _ A NASA spacecraft exploring Jupiter and its moons may be deliberately crashed to avoid any chance that it could strike and contaminate the moon Europa, where scientists believe simple life forms may exist.

Galileo, launched in 1989, has traveled 2.7 billion miles to study the giant planet.

A member of the Galileo imaging team says NASA are considering crashing the spacecraft into Jupiter or one of its icy moons in 2002 because it might still contain microbes from Earth.

``It was never put into quarantine or cleaned up before it left the Earth, though I can't imagine any bugs would be alive on it after all the radiation it's been exposed to,'' Kitt Peak astronomer Michael Belton said Wednesday.

``Just to be sure, they want to get rid of it and make sure it doesn't go into Europa, where we have a possible habitat of some kind of extraterrestrial life.''

Scientists suspect that Europa has an ocean beneath its ice shell that might contain simple life forms.

Galileo Project Manager Jim Erickson confirmed that the space agency is considering plunging the spacecraft into Jupiter, the moon Io or an icy satellite other than Europa.

Another option would be to aim the craft away from the planet and its moons ``so the odds are it will never hit anything,'' he said.

``We're looking at all kinds of options,'' said Erickson, who works at the Jet Propulsion Laboratory in Pasadena, Calif.

The $1.5 billion Galileo probe was launched in 1989 from the space shuttle Atlantis. It entered orbit around Jupiter in December 1995, and its two-year main mission was followed by a two-year extension that focused on Europa.

The Europa extension ended in January, and the battered probe has embarked on a new one, called the Galileo Millennium Mission. The craft completed its closest flyby of Io last month, passing 124 miles above the fiery moon. Galileo has begun relaying volcano pictures and other data from that encounter.

The Millennium Mission is expected to last until at least February 2001.