If you’ve ever wondered where the Earth came from, the answer, it seems, is ___1___—the solar wind. Or so say scientists who, after examining solar wind samples collected by the Genesis spacecraft, conclude that the inner planets of our solar system formed a little differently than we’d thought. The work appears in the journal Science. [Bernard Marty et al., "A 15N-Poor Isotopic Composition for the Solar System as Shown by Genesis Solar Wind Samples"]

Our solar system ___2___ a large, rotating cloud of interstellar debris called the solar nebula. The sun came first and the planets followed not long after.

But the new study shows that the ___3___ of oxygen and nitrogen isotopes found in the solar wind is different from the ___3___ here on earth, or on the moon or Mars. We’ve got more of the heavier versions of these atoms than our Sun does.

Now we just have to figure out why. Scientists say the ___4___ heavy nitrogen could have come from a comet. And the heavier oxygen from a natural process that left more of the light isotope in the part of the nebula that made the sun. So we are made of star stuff. But when it comes to our elemental composition, we’re not a ___5___.
【视听版科学小组荣誉出品】
blowing in the wind arose from ratio excess carbon copy
要问地球从哪里来？答案就是随风飘扬——随太阳风飘扬而来。检查了创世纪号太空船收集的太阳风样品之后，科学家们发现太阳系内行星的形成和人们之前想的不大一样。这项研究报告刊登在《科学》杂志上。 太阳系是星际碎片太阳星云中的大团旋转云演变而生的。首先出现的是太阳，不久之后其他行星陆续成形。 新的研究表明太阳风中发现的氧、氮同位素比例和地球上、月球上、火星上的大不相同。地球上氧、氮同位素原子要比太阳风中发现的重得多。 现在要解决为什么的问题。科学家们指出氮的超出重量可能来自彗星；重量较大的氧来自某种自然过程，在此过程中，大部分的轻同位素留在了形成太阳的部分星云中。因此，地球是星尘的产物。至于地球的元素构成嘛，那可不是仿制而成的哦~