有关陨石的知识，你都了解了吗？

王雨晴

A fireball lit up the sky on the evening of Dec 15， 2022 in Zhejiang. Instead of making wishes on this outer space object， some people were frightened， as the“fireball”was described as moving at a“very fast speed and very bright”， according to viewerscomments on Sina Weibo.

Qin Hongyi from the Zhejiang Astronomical Association assessed it as a“fireball”with a brightness far beyond the full moon， most likely a meteorite. Qin claimed that the object is over 10 centimeters wide， and it may not burn out completely during its fall. It was time of Geminid meteor shower activity recently， so the object might come from it， reported The Paper.

The remains of the“fireball”were later found in rural areas. Expert Zheng Yongchun at the Chinese Society of Space Research examined the remains and claimed that the meteorite has great value in investigating Earths early history.

According to NASA， scientists estimated that about 48.5 tons of materials， such as meteorites， fall on Earth each day. Almost all the material is vaporized in Earths atmosphere， leaving a bright trail called“shooting stars”. Several meteors per hour can usually be seen on any given night， which are often called meteor showers.

How does a meteorite land on Earth？ According to NASA， meteoroids， often seen as space rocks， enter Earths atmosphere at high speed and burn up， thus meteors occur. When a meteoroid survives a trip through the atmosphere and hits the ground， its called a meteorite. It is estimated that only 5 percent of meteorites can make it to Earths surface， and these can range from the size of a pebble to a fist.

Even knowing the science behind this alien event， you may still worry about the chances of being hit by a meteorite. According toUKmediaMirror，thechanceisprettysmall—about one in 840，000，000. There is only one record of a person being hit by a meteorite， which took place in 1954 in the US. The meteor crashed through the window and landed on the“lucky”ladyAnn Hodges.

2022年12月15日晚，一個“火球”照亮了浙江的天空。微博上有目击者留言称“火球”滑落时“速度极快、异常明亮”，因此人们都被这个外星来物吓坏了，而没有对着它许愿。

浙江省天文学会理事秦鸿翼判断称，这个“火球”亮度超过满月，很可能是一颗“火流星”（陨石）。他表示，“火球”的星体尺寸应该超过10厘米，在下落过程中可能不会燃烧殆尽。据澎湃新闻报道，近期正值双子座流星雨的活跃期，不排除火流星的出现和双子座流星雨有关。

后来，在农村地区有人发现了这个“火球”的残骸。中国空间科学学会的专家郑永春检查了这些残骸，称这块陨石在研究地球早期历史方面具有巨大价值。

据美国国家航空航天局（NASA）表示科学家估计，每天约有48.5吨陨石等物质落在地球上。而几乎所有物质都会在地球大气层中蒸发，并留下一条明亮的痕迹，我们称之为“流星”。任何一个晚上，人们在每小时里都可能看见数颗流星，通常将其称为流星雨。

陨石是如何降落在地球上的？据美国国家航空航天局称，流星体，也就是我们通常所说的太空岩石，高速进入地球大气层并燃烧，由此产生了流星。一个流星体穿过大气层并撞击地面时，就被称为陨石。据估计，只有5%的陨石能到达地球表面，这些陨石的尺寸从鹅卵石到拳头大小不等。

虽然知道了天降“火球”背后的科学原理，但你仍可能会担心有多大概率被陨石砸中。据英国媒体《镜报》报道，陨石击中人的可能性非常小，约为8.4亿分之一。从历史记录上看，世界上只有一个人曾被陨石击中，事情发生在1954年的美国，当时流星穿过窗户，落在了“幸运的”安·霍奇斯女士身上。