A Chinese astronomer viewing the live coverage on a US impactor hitting a comet said Monday in Beijing that the carefully-planned collision provides scientists the first look on comet nucleus, which is instrumental to a clearer understanding on the solar system formation.

Li Jing, a senior researcher with the Chinese Academy of Sciences (CAS) National Observatory in Beijing, said in an interview with Xinhua that the comet, Tempel 1, orbits around the Neptune where is very far from the Sun and moves near the Earth in every 5.51 years.

"Celestial bodies which move far from the Sun more possibly contain pristine substance which existed in early periods of solar system formation," Li said.

The successful strike 134 million kilometers away from the Earth occurred before 0600 GMT (14:00 Beijing Time) Monday, released mission control at the US National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory in Pasadena, California.

NASA blasted off a spaceship, named Deep Impact which coincides with a Hollywood 1998 movie, January 12 from Cape Canaveral, Florida.

The six-month suicidal voyage of the 590-kilogram spacecraft led to the first ever man-planned touch of a comet, which ignited dazzling fireworks in space.

The impactor's mothership has already sent back pictures after collision to the ground, according to NASA.

Another Chinese astronomer Wang Sichao who works for the CAS Nanjing Zijinshan Observatory, said over a telephone conversation earlier with Xinhua that comets have brought water, ice and organic substance to the Earth from the outer space.

"The Deep Impact mission will help the human being to explore origin of life on the Earth," Wang said.

"Organic stuff could evolve into life in suitable environment," Wang said, adding that study on comets might give scientists keys to unravel mystery of life beginning.

"Primordial ingredients inside the comet might also provide us clues on how the sun and other celestial bodies were formed," Wang said.

NASA said that the collision will not significantly change the orbital path of the dirty snowball, which might pose no threat to the Earth.

However, Wang said, the successful impact would teach scientists ways for evading future possible collision between comets and the Earth by bouncing comets with man-made spacecraft.

In 1994, a comet crashed into the Jupiter, which aroused worry among the Earth's residents.

Wang said his observation team has already taken pictures of Tempel 1 Saturday evening with a high-resolution telescope. His team will closely track the collision and movement afterwards.

Skygazers in the Western Hemisphere might able to see a shining brighter than normal.

An expert with Beijing Observatory said Chinese skygazers could also view the celestial fireworks, which might last for several hours after the collision, with professional telescopes.

A Beijing astronomy fan told Xinhua that he and his friends sharing similar interest surfed on websites, such as www.space.com and www.nasa.gov/deepimpact, to view live images.

Huang Chunping, a leading engineer who oversees the rocket system for China's first manned space mission in 2003, said that China is also able to send an impactor into the space to hit comets.

"But we still need to make sure that scientific data could be successfully transmitted back to the Earth via impactor's mothership," Huang said, citing that clouds of gas and dust after impacts would prevent data transmissions back to the Earth.