DARMSTADT, Germany - A European space probe has landed on the surface of Saturn's moon Titan after a seven-year journey, a space official said Friday, buoying hopes that the mission could shed light on the origins of life on Earth.

Mission controllers were confident the Huygens probe made a soft landing by parachute because it was transmitting steadily long after it was to have landed, said David Southwood, the European Space Agency's science director.

"We know that it has landed based on the laws of gravity," Southwood said. "It simply cannot still be flying. It's got to be on a solid surface, and it must be soft."

Southwood later announced that the probe had relayed scientific data - expected to include pictures and atmospheric measurements - to the Cassini mothership orbiting Saturn and the information had been transmitted back to Earth.

Applause erupted at mission control in Germany at news of the data transmission. The data is expected to shed light on what Titan's atmosphere and surface are made of - and possibly on the origins of life on Earth.

"The scientific data we are collecting now shall unveil the secrets of this new world," said Jean-Jacques Dordain, ESA's general director. "This is a fantastic success for Europe."

Friday's landing makes Titan the only moon other than Earth's to be explored by spacecraft.

The heart of the mission was its 2½-hour parachute descent, during which it was to take pictures and sample the atmosphere, believed to resemble that of the Earth when it was young.

Early signals confirmed it had powered up for entry and deployed the parachute, and officials were confident it had made a safe landing because Huygens was designed to go on transmitting from the surface for at least three minutes before its batteries died - a total transmission of less than three hours. But the signal had kept coming for more than five hours.

Mission officials - who have waited since 1997 for Huygens to reach its destination - had tears in their eyes as the first signal was picked up, indicating that the probe was transmitting to its mothership, the international Cassini spacecraft.

Huygens was spun off from Cassini on Dec. 24 to begin its free-fall toward Titan, the first moon other than the Earth's to be explored by spacecraft.

Named after Titan's discoverer, the 17th century Dutch astronomer Christiaan Huygens, the probe carries instruments to explore Titan's atmosphere and find out whether it has the cold seas of liquid methane and ethane that have been theorized by scientists.