#大學英語聽力
As objects go, Earth is getting on in years.
隨著物體的移動，地球在年複一年地向前發展。
But it is definitely not ancient by cosmic standards.
但從宇宙標准來看，它絕對不是遠古的。
The very oldest native planetary material we can examine are tiny zircon crystals that formed here about 4.4 billion years ago.
我們可以檢查的最古老的原生行星材料是大約44億年前在這裏形成的微小的锆石晶體。
But the universe has been around for approximately 13.8 billion years, and has been building stars and forging heavy elements since it was some 200 million years old.
但是宇宙已經存在了大約138億年，並且從大約2億年前開始就一直在建造ω星和锻造重元素。
That means that element-rich matter has been polluting interstellar space for a long, long while.
這意味著富含元素的物質已經汙染星際空間很長一段時間了。
Some of that matter, especially from older stars and supernova, has condensed and frozen into microscopic grains of silicate and carbon compounds.
其中一些物質，特別是來自較老恒星和超新星的物質，已經凝結並凍結成硅酸鹽和碳化合物的微觀顆粒。
Eventually those stardust grains might find themselves pulled into the gravity-well of new-forming stars, and planets.
最終，這些星塵顆粒可能會發現自己被拉入新形成的恒星和行星的重力井中。
But the vigor and turmoil of star and planet formation can erase the evidence of the age of those building blocks.
但是恒星和行星形成的活力和混亂可以抹去那些積木年代的證據。
Some of the most ancient crumbs of building material we can study are those inside certain kinds of meteorites that still conveniently fall to Earth.
我們可以研究的一些最古老的建築材料碎屑是那些在某些種類的隕石內部仍然方便地落到地球上的東西。
Stardust swept up as the solar system coalesced.
隨著太陽系的合並，星塵被掃了起來。