一詞：南極的雪中發現罕見宇宙塵埃
crucial ['kruːʃ(ə)l]
adj.決定性的；關鍵的
圖片來源：視覺中國
Scientists studying freshly fallen snow in Antarctica have uncovered a rare isotope of iron in the interstellar dust hidden inside it, suggesting the dust showed up recently.
研究南極洲新落雪的科學家在雪中隱藏的宇宙塵埃中發現一種罕見的鐵同位素，這表明這種塵埃是最近出現的。
This discovery could give us crucial information about the history of stellar explosions in our galactic neighbourhood.
這項發現或許給我們提供了銀河系附近行星爆炸歷史的關鍵信息。
We know that cosmic dust is drifting down to Earth all the time, tiny bits of debris from the rough and tumble of star and planet formation, sometimes billions of years old.
我們知道宇宙塵埃一直都飄向地球，這些塵埃來自恆星的混亂和行星岩層，有些已經數十億歲了。
Antarctica is a great place to look for such dust, because it's one of the most unspoilt regions on Earth, making it easier to find isotopes that didn't originate on our own planet.
南極是找尋這種塵埃的絕佳場地，因爲這是地球上最沒有受到破壞的地區之一。這使得找到非地球原產的同位素更加容易。
In this case, the isotope that researchers have pinpointed is the rare 60Fe (or iron-60), one of many radioactive variants of iron.
在這個案例中，研究員確定的同位素是罕見的60 Fe（或者鐵-60），鐵衆多的同位素中的一種。
Previously, the presence of this iron in deep-sea sediment and fossilised remains of bacteria has suggested one or more supernovae exploded in Earth's vicinity between 3.2 and 1.7 million years ago.
之前，這種鐵出現在深海沉澱物和細菌的化石遺骸中，表明一個或多個超新星在320萬年至170萬年前在地球附近爆炸了。
The new study marks the first time interstellar iron-60 has been detected in recent Antarctic snow - the dust would have fallen from the skies within the last 20 years, the researchers say.
這項新研究標誌着鐵60首次在最近的南極雪中被檢測到。研究員說，塵埃可能是在過去20年間從天空中掉落下來的。
"I was personally very surprised, because it was only a hypothesis that there might be iron-60 and it was even more uncertain that the signal is strong enough to be detected," nuclear physicist Dominik Koll from Australian National University told ScienceAlert.
“我個人覺得很驚訝，因爲那裏可能存在鐵60只是一個假設，信號能強到足夠被探測到就更不確定了。”澳大利亞國立大學的核物理學家多米尼克·科爾告訴ScienceAlert網（科學警報）。
今日詞彙
crucial ['kruːʃ(ə)l]
adj.決定性的；關鍵的
He played a crucial role in the merger talks.
他在這次企業併購談判中起着決定性的作用。
常見用法：to be crucial to sth. 對.......至關重要
