Title:Asteroid on collision course with Earth burns up hours after it was detected

An asteroid on a collision course with Earth has burned up in the evening sky over southern Africa eight hours after first being noticed.

在与地球的碰撞过程中，一个小行星在南部非洲的晚空中燃烧八小时之后才发现。

The asteroid, dubbed 2018 LA, was discovered out near the Moon's orbit early on Saturday morning.

这颗称为2018年洛杉矶的小行星于周六早上在月球轨道附近被发现。

Asteroid trackers at NASA and elsewhere determined the rock to be about 2 metres wide.

美国航天局和其他地方的小行星追踪者确定这块岩石宽约2米。

Automated alerts were sent out to the community of asteroid observers to obtain further observations, and to the Planetary Defence Coordination Office at NASA headquarters in Washington.

向小行星观察员社区发出自动警报，以获得进一步的观测，并送往华盛顿美国航天局总部行星防御协调处。

However, since the asteroid was determined to be so small, no further impact alerts were issued by NASA.

然而，由于确定小行星很小，美国航天局没有发出进一步的撞击警报。

Video posted on YouTube, from a farm just across the border in South Africa, showed a fireball swiftly descending and getting bigger, and then a blinding flash in the sky.

在南非边境的一个农场张贴在YouTube上的录像显示，一个火球迅速下降，变大，接着天空中盲目地闪光。

It burst apart several kilometres up, according to NASA.

Initial estimates had the impact zone stretching from southern Africa across the Indian Ocean into New Guinea, with tracking systems then narrowing it down to southern Africa.

初步估计的影响区从整个印度洋的南部非洲延伸到新几内亚。

NASA officials said the scramble among scientists and observers of the small asteroid was merely a good training exercise.

美国宇航局官员表示，小行星科学家和观察者之间的争斗只是一次很好的训练演习。

"This was a much smaller object than we are tasked to detect and warn about," NASA's planetary defence officer Lindley Johnson said in a statement.

美国宇航局的行星防御官员林德利·约翰逊在一份声明中说：“这个天体比探测和警告任务要小得多。

"However, this real-world event allows us to exercise our capabilities and gives some confidence our impact-prediction models are adequate to respond to the potential impact of a larger object."

"然而，这一现实世界事件使我们能够发挥我们的能力，并赋予我们某种信心，我们的影响预测模式足以应对更大的物体的潜在影响"。

It is the third-time scientists have spotted an incoming asteroid on a direct collision course with Earth.

这是第三次科学家在与地球直接碰撞的过程中发现了一颗进入的小行星。

In 2008, an asteroid measuring 4 metres was spotted 19 hours in advance. It came apart above Sudan, as predicted.

2008年，提前19小时发现4米的小行星。

A 2014 asteroid was discovered just a few hours before entering over the Atlantic, with little time for tracking.

2014年的小行星在进入大西洋上空之前仅仅几小时就被发现了，几乎没有时间跟踪。

All three asteroids were discovered through the Catalina Sky Survey near Tucson, Arizona, which is run by the University of Arizona and funded by NASA.

所有这些小行星都是通过亚利桑那州图森市附近的CatalinaSky调查发现的，该调查由亚利桑那大学管理，由美国航天局资助。

The same asteroid hunter, Richard Kowalski, made all three discoveries.

"We search the night sky methodically nearly each clear night," he said.

"While it is good fortune that I happened on this object, it is what our program is designed to do."

Objects this small, "are quite faint and hard to detect until they are very close, which is why we did not see it sooner", he said.

AP