The first planned contact with a comet, staged by the US Deep Impact mission yesterday, has left a significant impact on Chinese stargazers.

A NASA space probe hit its target, comet Tempel 1, at 0552 GMT (1:52 pm Beijing time) yesterday in a mission scientists hope will reveal clues about how the solar system formed.

One team of Chinese scientists, closely tracking the collision and the resulting fireworks, reported seeing a brighter Tempel 1 around 9:02 pm last night, said Yao Jinsheng, an astronomer at the Chinese Academy of Sciences' (CAS) Nanjing Zijinshan Observatory.

Cloud cover at the observatory in Xuyi, a two-hour drive from Nanjing, capital of East China's Jiangsu Province, prevented the team from seeing anything sooner.

They will analyze and evaluate the data they collected before making their findings public, Yao said by telephone.

The US National Aeronautics and Space Administration (NASA) launched the spacecraft, named Deep Impact after a 1998 Hollywood movie about a comet hurtling towards the Earth, on January 12 from Cape Canaveral, Florida.

The 590-kilogram spaceprobe's six-month, 431 million-kilometre voyage, as well as its meticulously planned destruction, has aroused extensive interest among the Chinese public.

The cosmic smash-up was broadcast live by China Central Television, with websites and radio talk shows discussing the event in detail, and explaining how people could see the results of the impact after nightfall.

Some scientists said the celestial fireworks might last for several hours after the collision.

The strike did not significantly alter the comet's orbit around the sun, and NASA said the experiment does not pose any danger to the Earth.

In 1994, a comet crashed into Jupiter, arousing fears that the same could happen to Earth.

Wang Sichao, another astronomer at the Zijinshan Observatory, said a successful impact may teach scientists ways to evade future possible collisions between comets and the Earth by hitting comets with man-made spacecraft.

"The Deep Impact mission will help us explore the origins of life on Earth," Wang said.

Li Jing, a senior researcher with the Chinese Academy of Sciences' National Observatory in Beijing, said Tempel 1 started near Neptune but now orbits between Mars and Jupiter and moves near the Earth every 5.51 years.

"Celestial bodies that move far from the sun are more likely to contain pristine substances that existed in early periods of the solar system's formation," Li said.

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

Huang Chunping, a leading engineer who oversaw the rocket system of China's first manned space mission in 2003, said China could also send an impactor into space to hit a comet.

"But we still need to make sure that scientific data could be successfully transmitted back to the Earth via the impactor's mother ship," Huang told the Xinhua News Service.

Clouds of gas and dust after impact could prevent the transmission of data back to the Earth, he said.

An image of the crash taken by the mother ship, which released the barrel-sized "impactor" probe on its suicide mission 24 hours earlier, showed a bright spot in the lower section of the comet where the collision took place.

A cloud of debris was hurled into space. When the dust settles, scientists hope to peek inside the comet's frozen core - a composite of ice and rock left over from the early solar system.

"We hit it just exactly where we wanted to," said Don Yeomans, a scientist at NASA's Jet Propulsion Laboratory, in Pasadena, California.

The spectacular collision, 134 million kilometres from Earth, marked the first time a craft has come into contact with a comet's nucleus.

(China Daily 07/05/2005 page1)