當年今日﹕New Horizons sent into space
【明報專訊】On 19 January 2006, New Horizons (新視野號), an interplanetary space probe (星際深空探測器), was launched into space from the John F Kennedy Space Centre in Florida, the US. Having performed a fly-by of Pluto (冥王星), it has sent scientists breathtaking pictures of the dwarf-planet (矮行星) that were never seen before.
The adventure of New Horizons
New Horizons is part of the New Frontiers programme being conducted by NASA (美國太空總署). The purpose of the programme is to research several of the Solar System's planets including Jupiter (木星), Venus (金星) and the dwarf planet Pluto.
On 19 January 2006, New Horizons was launched directly into an Earth-and-solar escape trajectory (軌道) at a speed of about 16.26 kilometres per second. The space probe made its closest approach to Jupiter on 28 February 2007, at a distance of 2.3 million kilometres. On 14 July 2015, it flew 12,500 kilometres above the surface of Pluto, becoming the first spacecraft to explore the dwarf planet.
New Horizons revealed to us the spectacular landscape of Pluto unknown to scientists before. The dwarf planet has been found to feature vast, smooth plains, towering ice mountains and a blue haze of hydrocarbons. Scientists say this is a surface unlike any planetary surface they have ever seen. The bright, smooth region named Sputnik Planum, for example, is a plain of frozen nitrogen that covers hundreds of miles.
Pluto —— from a planet to a dwarf planet
Those who were in primary school two decades ago - or even earlier - must have been told Pluto was a planet like the Earth for that was what scientists used to think. But in 2006, they discovered Eris (鬩神星), a rocky body that is even larger than Pluto. Scientists at first regarded Eris as a planet as well. That led to the announcement that the Solar System contained ten planets. As more and more objects like Eris were discovered, scientists redefined the term "planet". They also coined a new term "dwarf planet", which now includes Pluto and Eris.
What about China?
What New Horizons has sent to Earth has pushed back the boundaries of space exploration. It has also extended the US's lead in aerospace science and technology. So what about China? Though still lagging behind the US and Russia, China has made great strides in the field since 1956, when Qian Xuesen (錢學森), a Chinese expert in missiles, gave Mao Zedong (毛澤東) a roadmap of developing aerospace science and technology. In 1970 Dong Fang Hong I (東方紅一號), the first space satellite made by China, was launched successfully. In 2003 Yang Liwei (楊利偉) became the first Chinese astronomer to be sent into space by the Chinese.
China's recent breakthrough was made in 2012, when Shenzhou 9 (神舟九號), a manned spacecraft of China's Shenzhou programme, was launched into space. Carrying on board Jing Haipeng (景海鵬), Liu Wang (劉旺) and Liu Yang (劉洋), China's first female astronant, the spacecraft docked with the Tiangong 1 (天宮一號) space station on 18 June that year.
