介绍： Scientists spot mystery object believed to come from beyond solar system
It isn't a bird, it isn't a plane and it certainly isn't Superman – but it does appear to be a visitor from beyond our solar system, according to astronomers who have discovered a new object hurtling through our cosmic neighbourhood.
 
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介绍： Scientists spot mystery object believed to come from beyond solar system
It isn't a bird, it isn't a plane and it certainly isn't Superman – but it does appear to be a visitor from beyond our solar system, according to astronomers who have discovered a new object hurtling through our cosmic neighbourhood.
 
The object, originally called A11pl3Z and now known as 3I/Atlas, was first reported by the Asteroid Terrestrial-impact Last Alert System (Atlas) survey telescope in Río Hurtado, Chile, on Tuesday.
 
According to Nasa, subsequent analysis of data collected by various telescopes before this date has extended observations back to 14 June, and further observations have also been made. As a result, experts have been plotting the path of the visitor.
 
Dr Mark Norris, a senior lecturer in astronomy at the University of Central Lancashire, said: “If confirmed, it will be the third known interstellar object from outside our solar system that we have discovered, providing more evidence that such interstellar wanderers are relatively common in our galaxy.”
 
While the nature of the new visitor was not initially apparent, the Minor Planet Center has revealed that tentative signs of cometary activity have been spotted, noting that the object has a marginal coma and short tail. As a result, the object has been given the additional name of C/2025 N1.
 
While some experts have suggested the object could be as large as 12 miles (20km) in diameter – bigger than the space rock that wiped out the non-avian dinosaurs – it seems Earth residents do not need to worry.
 
Nasa said: “The comet poses no threat to Earth and will remain at a distance of at least 1.6 astronomical units [about 150m miles].”
 
Colin Snodgrass, a professor of planetary astronomy at the University of Edinburgh, said the object could turn out to be smaller.
 
“Based on the brightness reported in the initial observations, that translates to a 20km asteroid if you assume typical properties, but only if you assume it is an asteroid and not a comet,” he said. “There are reports that it shows a small comet-like tail, so that implies a lot of the brightness will be from the coma (atmosphere) of dust around the object, and it is likely that the solid nucleus is smaller.”
 
Nasa said the object would reach its closest approach to the sun around 30 October, coming within about 130m miles of the star – or just within the orbit of Mars. The comet is then expected to leave this solar system and head back out into the cosmos.
 
spot /spɒt/ v. 发现
📗例句：She spotted her friend in the crowded supermarket.
（她在拥挤的超市里发现了朋友）
🥝搭配：spot a mistake 发现错误
mystery /ˈmɪstri/ n. 神秘事物
📗例句：The locked box in the attic was a complete mystery.
（阁楼上锁着的盒子是个谜团）
🥝搭配：solve a mystery 解开谜团
approach /əˈprəʊtʃ/ v. 接近
📗例句：The deadline is approaching quickly.
（截止日期正在快速临近）
🥝搭配：approach a problem 处理问题
diameter /daɪˈæmɪtə(r)/ n. 直径
📗例句：The pizza has a diameter of 30 centimeters.
（这个披萨直径30厘米）
🥝搭配：measure the diameter 测量直径