Water.Earth has loads of H2O.
水,地球上有着丰富的水资源。
But did it always?
但一直是这种情况吗?
This question has plagued scientists for decades.
这个问题几十年来一直困扰着科学家们。
Conventional wisdom has it that the Earth formed without any water.
传统观点认为地球形成之初并没有水。
Then meteorites carrying water smashed into the planet, dumping their precious cargo.
而后经过携带水陨石的撞击,地球才有了珍贵的水资源。
But now, a team of geologists has challenged this idea.
但现在,一组地质学家们对此观点提出了质疑。
They say water may have been here from the start.
他们认为水资源从一开始就已经出现在地球上。
The scientists discovered that the chemical signature of water on Earth matches the signature of water in an ancient group of asteroids called eucrites.
科学家们发现地球上水的化学特征与一个名为钙长辉长陨石古老小行星群上水的化学特征匹配。
These bodies formed just a few million years after the birth of the solar system.
而这些小行星形成于太阳系诞生几百万年后。
And because Earth and eucrites seem to share the same source of water, the reasoning goes, Earth must have gotten its water around the same time the eucrites did—which has big implications.
且由于地球似乎跟这个小行星群共享着同一水源,因此地球应该和这个小行星群同一时期拥有水源—这样的推理影响重大。
“Because Earth got its water early—really the whole inner solar system got its water early—it means that planets, once they fully formed and got cool enough that water would be stable on the surface, they could be habitable.”
“由于地球很早就有水资源,整个太阳系也在很早就有了水资源。这就意味着,行星一旦完全成形且温度足够低的话,水资源将会在表面趋于稳定,这样行星就会适于居住。”
The Woods Hole Oceanographic Institution's Adam Sarafian, who led the research.
领导这项研究的伍兹霍尔海洋研究所亚当?萨拉芬恩说道。
“It wasn't like these planets are just waiting around, looking at their watches, saying,Where's the water?
“事实上那些行星并不会墨守成规等待,看着手表大喊大叫水在哪里?
Life's ready to go, we just need water here.
生命已准备好诞生,现在唯独就差水源。
So it pushes the date at which planets can become habitable back.
因此这种理论提前了行星适宜居住的时间。
And we need to go back to the drawing board on how planets are built and how water survives large impacts.”
而我们需要理清头绪研究行星如何构成及水资源在其中有着怎样的巨大影响。