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“l(fā)ucky”ladyAnn Hodges.

2022年12月15日晚，一個(gè)“火球”照亮了浙江的天空。微博上有目擊者留言稱“火球”滑落時(shí)“速度極快、異常明亮”，因此人們都被這個(gè)外星來物嚇壞了，而沒有對(duì)著它許愿。

浙江省天文學(xué)會(huì)理事秦鴻翼判斷稱，這個(gè)“火球”亮度超過滿月，很可能是一顆“火流星”（隕石）。他表示，“火球”的星體尺寸應(yīng)該超過10厘米，在下落過程中可能不會(huì)燃燒殆盡。據(jù)澎湃新聞報(bào)道，近期正值雙子座流星雨的活躍期，不排除火流星的出現(xiàn)和雙子座流星雨有關(guān)。

后來，在農(nóng)村地區(qū)有人發(fā)現(xiàn)了這個(gè)“火球”的殘骸。中國空間科學(xué)學(xué)會(huì)的專家鄭永春檢查了這些殘骸，稱這塊隕石在研究地球早期歷史方面具有巨大價(jià)值。

據(jù)美國國家航空航天局（NASA）表示科學(xué)家估計(jì)，每天約有48.5噸隕石等物質(zhì)落在地球上。而幾乎所有物質(zhì)都會(huì)在地球大氣層中蒸發(fā)，并留下一條明亮的痕跡，我們稱之為“流星”。任何一個(gè)晚上，人們在每小時(shí)里都可能看見數(shù)顆流星，通常將其稱為流星雨。

隕石是如何降落在地球上的？據(jù)美國國家航空航天局稱，流星體，也就是我們通常所說的太空巖石，高速進(jìn)入地球大氣層并燃燒，由此產(chǎn)生了流星。一個(gè)流星體穿過大氣層并撞擊地面時(shí)，就被稱為隕石。據(jù)估計(jì)，只有5%的隕石能到達(dá)地球表面，這些隕石的尺寸從鵝卵石到拳頭大小不等。

雖然知道了天降“火球”背后的科學(xué)原理，但你仍可能會(huì)擔(dān)心有多大概率被隕石砸中。據(jù)英國媒體《鏡報(bào)》報(bào)道，隕石擊中人的可能性非常小，約為8.4億分之一。從歷史記錄上看，世界上只有一個(gè)人曾被隕石擊中，事情發(fā)生在1954年的美國，當(dāng)時(shí)流星穿過窗戶，落在了“幸運(yùn)的”安·霍奇斯女士身上。