National Aeronautics and Space Administration technicians in charge of Jupiter's final mission lost contact with Galileo shortly after 1940 hours GMT Sunday.

However, the probe was lost almost a hour before this, as it took some 52 minutes for Galileo's transmissions to reach earth.

NASA technicians put Galileo on a crash course with Jupiter rather than risk the craft hitting one of Jupiter's moons, where Galileo had discovered underground oceans.

Galileo's 14-year mission was drawn to a close as the craft had run low on fuel.

"I'm just a little sad, but Galileo has done a tremendous job for us, and it's a nice ending for it," Claudia Alexander, Galileo project manager at NASA's Jet Propulsion Laboratory (JPL), in California, said in a press conference.

The probe had notably discovered the existence of an underground ocean on Europa, one of Jupiter's moons, during its voyage.

"Basically we discovered an ocean, it's the most important discovery in decades for scientific exploration. The last time was 500 years ago, it was the Pacific Ocean," Alexander stressed.

NASA hopes to explore Jupiter's four moons further in future missions currently being planned.

The end of the mission gave NASA a chance to showcase the successes of its unmanned space probes, even as the agency faces widespread criticism over the Columbia space shuttle disaster.

Galileo transmitted data back to NASA until its signal was lost for good.

The 1.35-tonne probe entered Jupiter's hostile atmosphere just south of the planet's equator at a speed of 48.2 kilometers (30 miles) per second.

Galileo, which had circled Jupiter 34 times, discovered that Europa -- one of Jupiter's four moons -- likely has an underground ocean.

NASA technicians feared Galileo could contaminate that ocean with microbes carried from Earth if it had collided with Europa, and thus affect a potential source of life and future scientific discovery.

Galileo was named after 17th Century Italian astronomer Galileo Galilei, who discovered Jupiter's four key moons.

The probe also discovered oceans on Ganymede and Callisto as well as volcanic activity on Jupiter's fourth moon, Io.

Launched in October 1989, Galileo arrived at Jupiter in December 1995.

It took about 14,000 pictures during its lifetime. It was the first spacecraft to pass near an asteroid, and the first to discover a moon of an asteroid.

It was also the first spacecraft to directly measure with a probe the atmosphere of Jupiter, the largest planet in the Earth's solar system, and was the first to carry out long-term observations from orbit.

SPACE.WIRE