經濟學人世界新聞簡訊 - 2023/9/24

NASA太空船將帶回小行星碎片，有助了解地球和生命的起源

美國太空總署（NASA）的太空船OSIRIS-REx將於週日（9月25日）返回地球，帶回小行星Bennu的碎片。這項耗資10億美元的任務始於2016年，旨在收集小行星樣本。雖然這些岩石的重量最多只有幾百克，但其價值卻遠不止於此。

這是因為兩個原因。首先，小行星是太陽系形成後殘留的塵埃和氣體團塊，但它們從未生長到足夠大以成為行星。科學家們通過研究小行星來了解地球和生命的起源。其次，Bennu是NASA認為可能撞擊地球的2400顆小行星之一，科學家們正越來越努力地了解它們。2024年，歐洲太空總署（ESA）將發射一個名為Hera的探測器，以分析如何避免小行星撞擊。而OSIRIS-REx本身也將於2029年訪問小行星Apophis，該小行星預計將危險地飛過一些地球衛星下方。

On Sunday OSIRIS-REx, a NASA spacecraft, will drop a chunk of an asteroid called Bennu. The payload will float down from space and land in the desert in Utah. The billion-dollar mission launched in 2016 to collect its sample. Though the rocks weigh at most a few hundred grams, its size belies its value.

That is for two reasons. Asteroids are leftover chunks of dust and gas that agglomerated after the solar system was formed, but never grew large enough to become planets. Scientists study them to understand how Earth—and life—evolved. The second reason is even more pressing: Bennu is one of 2,400 asteroids that NASA thinks may hit Earth, and which scientists are increasingly trying to understand. In 2024 the European Space Agency will launch a probe named Hera to analyse how asteroid collisions may be averted. And OSIRIS-REx itself will visit the asteroid Apophis, which is due to fly dangerously below some Earth satellites, in 2029.

_{Sources: https://www.economist.com/the-world-in-brief
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